Zinc is present in nearly all body tissues, especially the thyroid, pancreas and reproductive organs. This mineral is involved in the body’s enzymatic reactions, the synthesis of proteins and in carbohydrate metabolism.

Zinc as a trace mineral is second only to iron in abundance in humans.

Because Zinc is essential to cell formation, it is needed for healing and maintaining healthy tissues

Growth related problems and fatigue could be related to the role of zinc in protein synthesis, enzymes, and absorption. Mental and emotional problems could be related to zinc's role with histamine as a neurotransmitter in the hippocampusmossy fiber structure of the brain. A palpable spleen might be related to zinc deficiency induced increase in spleen seeking suppressor T-cell lymphocytes (Ref. 21). Thymic atrophy could result due to the basic nutritional need for zinc by the thymus. Zinc is a functional part of the retina and is helpful in treating cataracts of the elderly. Acne and other skin problems can be a zinc deficiency. Zinc is very helpful in alleviating acne. Diaper rash often dramatically responds to zinc oxide lotion.

As more information about the clinical hallmarks of the zinc deficiency syndrome is understood, the following are currently believed to be markers of zinc deficiency: hypozincemia, iron deficiency anemia, hepatosplenomegaly, growth retardation, arrested sexual maturation, partial adrenal insufficiency, anorexia, dryness and hyper pigmentation of the skin, impaired taste and smell acuity, delayed wound healing, sub optimal growth, poor appetite, pica, impaired immune response. Diseases that are known to be associated with zinc deficiency include malignancy and many other diseases.

Low consumption of animal protein, geophagia, parasitic infestation, hemolysis, blood loss, high intake of dietary fiber, alcoholism, liver disease, malabsorption, renal diseases, burns, pregnancy, oral contraceptives, penicillamine therapy, poor appetite, chronic debilitation, Crohn's disease, cystic fibrosis, sickle cell anemia, malignancy, sweating, excessive consumption of food products process with EDTA or other metal chelators (used to prevent spoilage), poisoning by heavy metals such as lead and cadmium, and starvation are often accompanied by zinc deficiency.

Surgery has been shown to occasionally cause a permanent disturbance to zinc metabolism, unless 1 to 5 mg zinc/pound body weight is administered during and after (several days to several months) healing process.

In the case of growing children, competition for zinc is so intense and the opportunities for zinc deficiency so numerous that normal dietary zinc intake may be quite inadequate to supply all of the growing child's needs. The result being that faulty cell mediated immunity and excessive mast cell degranulation occur with an increase in viral illnesses, allergy, and malignancy, along with failure of other zinc dependent functions such as growth.

In the saliva, atoms of zinc with its 2+ electrical charge from lozenges are water soluble and ionizable. The zinc ions combine with 4 to 8 molecules of water to form hydrated, or solution, zinc ions carrying a 2+ charge. Unlike the metal zinc, solution zinc ions (Zn²⁺ ions) have powerful, and strongly beneficial effects on upper respiratory infections (rhinovirus common colds). Rhinoviruses, one of the five genera of the picornavirus RNA virus family of which much is known, are now known to be the cause of the great majority of colds.

Colds are infections of the nasal cavity - and especially infections of the highly vascularized nasal mucosal turbinates of the nasal cavity. The digital helical CT studies by Shigeru Ishikawa, MD, PhD, of the Department of Otolaryngology at Kanazawa Municipal Hospital, Japan, greatly help visualize the nasal cavity itself, and particularly the highly vascularized mucosal turbinate tissues covering the nasal turbinate bones. According to Dr. Ishikawa, the images marked as "untreated" are similar to what one would find in a person experiencing a common cold.

Bruce Korant, PhD, of Du Pont Chemicals showed in Nature in 1974, that Zn²⁺ ions were strongly antirhinoviral. Others have shown that Zn²⁺ ions help T-cell lymphocytes release large amounts of interferon-gamma, a powerful antiviral agent. Other functions of Zn²⁺ ions helpful in treating or curing common colds include anti-inflammatory activities, destruction of histamine, stabilization of cell plasma membranes (prevents cell leakage, congestion and runny nose), and stimulates T-cell lymphocytes into action.

Wouldn't a nasal spray releasing Zn²⁺ ions be the real cure? It certainly seems logical! But, nature says, "No way!" Nasal sprays and nose drops releasing Zn²⁺ ions have been used for over a century as a mild, short acting, nasal decongestant having no role in shortening colds or curing colds. In his 1990 European patent Application (number 381522) Professor Derek Bryce-Smith of the University of Reading, Great Britain, found that frequent administration of strong zinc sulfate nose drops provided only a mild nasal decongestant effect -- consistent with literature published in the 1930s.

Conversely, Zn²⁺ ions released into the mouth can shorten or cure common colds because they are absorbed into tissues through the mouth-nose biologically closed electric circuit (BCEC), a recently discovered feature of human physiology. The directionality of the mouth-nose BCEC is easily demonstrated with an ohmmeter. Simply reversing the leads shows a diode-like differential in resistance. Zn²⁺ ions from nasal spray or drops are repelled from nasal tissue surfaces by the same mouth-nose BCEC.

Zinc gluconate lozenges releasing Zn²⁺ ions at 5 to 8 millimolar concentration kept in contact with the oral mucosa for 20 to 30 minutes used nine times a day definitely shortened common cold symptoms by 5 to 7 days! This astonishing effect was documented in two independent clinical studies, one in the U.S. in 1984, and the other in Great Britain, at the Medical Research Council Common Cold Unit (MRC) in 1987. As follow up to these reports, many common food ingredients (aspartic, citric, tartaric, other food acids, acacia, and strong bases) were used in other studies of "flavor masked" zinc lozenges in experimental therapy of colds. The researchers did not know that those chemicals strongly bound Zn²⁺ ions rendering those lozenges ineffective against colds, setting back common cold research by 10 years or more.

The technology behind efficacious zinc lozenges involves complex mathematics in the arcane field of solution chemistry. That is a study of what happens to metal compounds when they are dissolved in water. As shown in the figure, zinc chloride and zinc acetate release 100% of their zinc as antirhinoviral Zn²⁺ ions at physiologic pH 7.4, while zinc gluconate releases 30% of its zinc as Zn²⁺ ions at pH 7.4 according to solution chemistry calculations by Guy Berthon, PhD, INSERM Unit 305, Toulousse, France. These three merited close study. Other common zinc compounds do not release Zn²⁺ ions at physiologic pH 7.4 and have no utility in treating common colds. Zinc chloride reacted with lozenge ingredients, because it was too unstable. Zinc gluconate mixed with sweet tablet bases (except fructose - see MRC study) became offensively bitter after lozenges aged for a while.

Properly prepared zinc acetate lozenges release 100% of their zinc as Zn²⁺ ions at physiologic pH. They shorten common colds dependent only upon zinc ion availability (ZIA), a name for zinc lozenge strength derived from Fick's laws of permeability, the pharmacology law governing absorption of solutes through membranes and tissues. Efficacy starts at a ZIA strength of 25, where colds last a day or two less than normal (and treatment is hardly worthwhile). Amazingly, stronger ZIA 50 zinc acetate lozenges were strong enough for the U.S. Patent and Trademark Office to grant the world's first and only "Cure for Common Cold" patent. Lozenges having a ZIA strength of 50 to 100 shorten colds symptoms by 5 to 7 days; and lozenges having a ZIA 100 or higher strength often result in a "cure" in less than a day with no further treatment.

In a case of Acute Lymphocytic Leukemia (ALL)in a 3-year-old white female treated with CCG protocol 161, regimen 2 a bone marrow remission from 95+% blast cells to an observed zero blast cell count (not M-1 but M-0) occurred within 14 days of treatment.

During this same period adult therapeutic doses of all known vitamins (except folic acid) and all minerals and trace minerals were also given. In addition to the reduction of blast cells to an observed count of zero, red blood cell production and other hemopoietic functions returned to a modified normal condition at a clinically remarkable rate. No adverse effects of the chemotherapy were observed. Since most remissions after 30 days of treatment still show 3-5% blasts in the bone marrow, the question "Had there been an unknown but positive interaction between one or more of the supplemental nutrients and the chemotherapy?" was asked by the clinicians and parents. Research was initiated to ascertain if a nutrient deficiency could cause symptoms found in pre-leukemia and leukemia; and if such nutrient exists, would a positive interaction occur if it were administered as an adjunct to chemotherapy. If a nutrient could be shown to accelerate and strengthen the function of chemotherapy or the immune function, then it could be expected that the relapse rate could be lessened since the relapse rate to both the rate at which a remission is obtained and the thoroughness of the elimination of leukemic blasts.

Based upon a review of the available literature, only zinc deficiency or zinc metabolism errors could theoretically cause all of the pre-leukemic conditions of allergy, loss of viral and tumoral immunity, asparagine production, growth suppression and other commonly observed pre-leukemic conditions. It was noted that leukemic cells contain much less zinc than normal lymphocytes which may be very important since zinc is vital for proper genetic and cellular function. Zinc metabolism deviations have been recognized in leukemia since 1949, but not well understood, although zinc was used in the early 1950s as a therapeutic drug in the treatment of leukemia. Zinc may function therapeutically in leukemia by augmenting L-asparaginase in killing leukemic cells (since a zinc deficiency may induce free asparagine), and by stimulating cell mediated immunity. Zinc is believed to have been the only nutrient that could have had a positive interaction with any of the chemotherapeutic drugs in CCG protocol 161 regimen 2.

In the child's remission, zinc at 1-2 mg/pound of body weight was not observed to cause an increase in lymphocyte count, but may have improved T-cell immune function. Zinc may have aided in restoring normal growth while using corticosteroids in a monthly pulse protocol. Zinc is known to stimulate effector T-cell function and increase the number of effector T-cells, even in leukemia, which may have aided in the destruction of residual leukemic cells, through amplification of the plaque-forming cell function of T-cells. Zinc is the body's only T-cell lymphocyte activator.

In studies to ascertain the practical role of zinc in related hematological functions, zinc was found effective in increasing immunity to upper respiratory viruses and infections in general in normal people and leukemic children, management of Type I allergy and growth restoration in both normal and leukemic children. Therapy of the common cold with zinc yielded extremely rapid recoveries which strongly suggested that a zinc-viral antigen complex was highly stimulatory to interferon induction, and/or that the direct inhibition of rhinovirus by zinc may be highly practical and effective in vivo. Identical responses to zinc supplementation as an adjunct to standard treatment occurred in about one dozen children when zinc treatment was started with standard treatment between 1985 and 1997.

Pre-Acute Lymphocytic Leukemia in the child is often, but not always, marked by: (1) severe atopic-like allergic reactions, (2) major and/or frequent upper respiratory viral infections and fevers, (3) taste and appetite suppression, (4) growth suppression, (5) lethargy and depression, (6) diarrhea, and (7) offensive body odor. These symptoms are more often noted by the family and pediatrician than by the oncologist. They have not previously been associated with leukemia in terms of their having a common nutritional origin.

The occurrence of one or more of these symptoms is frequent enough in the year preceding the onset of ALL to suggest that there may be a nutritional linkage, or common denominator, between them individually and between them and leukemia. Obviously, they are not normally predictive of leukemia. In fact, many are typical of what has come to be considered as normal childhood problems that eventually go away with or without treatment, although nutritional deficits could still be causal.

Since no other etiology of leukemia exists, this backward-looking approach seemed to offer at least a chance to develop an hypothesis concerning the etiology of leukemia.

Since many of the classical symptoms of leukemia were known to result from an active disease, no rationale for their repeated study existed. These classical symptoms include anemia, ease of bruising, fever, nightsweats, splenic, liver and lymph gland enlargement, peripheral blasts, petechiae, bone or joint pain, and hemorrhage.

If leukemia is to be prevented or its incidence lessened, a better understanding of the role of individual nutrients in the etiology of pre-leukemia symptoms appeared to be necessary. If a role for a single nutrient could be found for each of the symptoms of pre-leukemia, leukemic cell involvement, and recovery, a major break-through in the prevention of childhood leukemia via nutritional means could eventually be forthcoming.

In a direct review of over 10,000 medical journal and clinical nutrition journal articles published between 1976 and 1981, and review of computer searches of the world medical literature, only zinc deficiency was found to have a role in the occurrence of the seven pre-leukemic cells; and by reversing the zinc deficiency killing leukemic cells, reducing asparagine, and stimulating immunity to the leukemic cells. Several other nutrients had roles in one or another symptom or function, but only zinc was functional in each of them.

The following is a review of the role of zinc in the management and cause of the pre-leukemic symptoms. It is from the zinc perspective that many previously unrelated symptoms seem to share a common genesis. The role of zinc in leukemia and other activities is presented elsewhere within this review. The full role of zinc in human nutrition is outside of the scope of this review, and certain obvious roles of zinc such as its role in the male reproduction system are purposefully omitted.

ALLERGY

Mast cells and basophils are commonly known to be the mediators of Type I allergy. Hayfever, food allergy, asthma, croup, gastrointestinal allergy, and anaphylaxis are manifestations of Type I allergy. Allergic reactions result from the release of histamine, heparin, slow-reacting substance of anaphylaxis (SRS-A) and kinins from the cell's granules. The release, generally, is caused by a reaction of antigen with mast cells or basophils coated with IgE antibody. This reaction causes a degranulation of the cell's contents and active transport of the cell's contents through the cytoplasmic membrane of the cell.

The granules of both basophils and mast cells also contain zinc ions. These ions stabilize the cell and prevent induced histamine and other component release from mast cells if sufficiently available. When released, zinc can contribute significantly to several immune reactions described in other parts of this review. It is believed that this effect of zinc is attributable to its action on the cell membrane. It has been speculated that zinc may form mercaptides with thiol groups of proteins, possibly linking to the phosphate moity of phospholipids or interaction with carboxyl groups of sialic acid or proteins on plasma membranes, resulting in a change of fluidity and stabilization of membranes.

There are also several enzymes attached to the plasma membrane which control the structure of the membrane, and the activation of these enzymes may be controlled by zinc. Adenosietriphosphatase (ATPase) and phospholipase A2 are known to be inhibited by zinc, and this effect may explain immobilization of energy-dependent activity of plasma membrane or increased integrity of the membrane structure.

Several receptors at the plasmatic membrane presumably function as a gate for transmitting information to intracellular space. In the case of mast cells, histamine-releasing agents seem to work through specific receptors at the membrane. Masking of such receptor sites by membrane impermeable Zn:8-hydroxyquinolone would thus explain the inhibition of the release reaction.

The role of Ca2+ in the function of cell microskeleton, represented by microtubules and microfiliments, has been well documented. The contractile elements of this system are in some way responsible for the mobility of microorganelles and transport of granules to the membrane as well as excitability of the plasma membrane itself. Since zinc is known to compete with calcium, it may thereby inhibit this effect of calcium.

In addition to histamine's role as a mediator of Type I allergy, histamine also has direct T-cell immunosuppressive aspects which are discussed elsewhere in this review.

Inhibition of histamine release begins at about 10^-6M concentration of zinc ions (in humans) and is maximum at 10^-4M concentration (10 times the normal 10^-5M concentration). Zinc is released with histamine and may have an antiviral function. Fifty mg zinc with each meal has been shown to be beneficial in the treatment of allergic diseases (urticaria and erythema multiforme) where zinc serum levels were low (65 mg dl)or 65% normal (Ref. 75).

It may very well be that the known zinc serum level reductions so often found in leukemic children are the cause of the severe allergy-like symptoms that precede leukemia. That they occur in children for as long as a year before leukemia occurs may result from a powerful LEM-like reaction and possibly the leukemia inducing agent (virus?) itself. Clearly, the release of histamine, unchecked by sufficient zinc ion concentration is immunosuppressive.

VIRAL AND TUMORAL IMMUNITY

The T-cell lymphocyte response is the basis of cellular mediated immunity (CMI). The CMI is vitally important in protection against virus, fungal and protozoan infections, as well as against malignant and autoimmune disease. Effector T-cells may be thought of as the immune system's "field commanders," responsible for the initiation and regulation of immune responses from other effector T-cells, suppressor T-cells (including cytotoxic natural killer cells), ß cells, and other white cells. They also interact with these cells in numerous immunological events designed to present the best immune response. Antigen sensitized T-cells, upon second exposure to the antigen, transform to an activated form, lymphoblasts, which can directly lyse the antigen, or release soluble factors, lymphokines, which aid in the destruction of the target cell or antigen. Interferon is released upon exposure of T-cells to mitogens or specific antigens. Effector and suppressor T-cells may be distinguished from each other through their responses to mitogens.

A search was made for disease models having nutritional response to impaired cell mediated immunity. Genetic causes of impaired cell mediated immunity and congenital defects of CMI were reviewed and considered.

Vitamin A, B complex, and C, zinc, proteins and lithium were found to have a role in the nutrition and function of the CMI. In nutritional deficiency, in general, there is often found significant immune system impairment. A reduced number of T-cells, an impairment of delayed hypersensitivity, an impairment of mitogen and antigen induced lymphocyte DNA synthesis, a reduction in soluble factors released, an increase in the number of null cells, a relative decreases in the T-cell/ß-cell ratio (with ß-cells usually unchanged). increased IgE, lowered IgG, IgA and IgM, unchanged phagocytosis, depressed serum transferrin levels, decreased serum levels of most complement components and other immune system alterations are observed in various states of malnutrition. In mild under nutrition in children without growth retardation, alterations in immunity function are less frequent.

No specific disease model was found in this study wherein the normal CMI response was depressed and could be normalized by restoration of a single nutrient except for zinc. This includes scurvy and Vitamin C. In fact, scurvy causes no characteristic change in the leukocytes at all. However, it has recently been found that Vitamin C and hyperthermia produce a modest enhancement of the immune response to influenza virus.

Some examples: Thymic regrowth and cell mediated immune response after recovery from protein-energy malnutrition was observed not to take place until after a modest supplementation of zinc ( 2 mg zinc per kilogram of body weight was given. Cell mediated immunity returns when zinc is administered in acrodermatitis enteropathica. Depressed cell mediated immunity returns when zinc is administered in Down's Syndrome. Down's Syndrome has a probability of leukemia 30 times normal, when unsupplemented. It remains to be determined if zinc will alter the leukemia rate in these children. In other conditions such as general malnutrition and parenteral nutrition, zinc restores depressed cell mediated immunity.

Since the CMI response is also responsible for tumoral immunity, it becomes important to understand the stimulating effect of zinc on CMI in the presence of phytohemagglutinin (PHA) in vitro or antigens in vivo. Zinc has a specific mitogenic effect on PHA stimulated T-cell lymphocytes (Refs. 3,6,16,17). PHA is a specific effector T-cell mitogen vitro. Lymphocytes from rats fed a diet high in zinc were most susceptible to PHA transformation. Within 3 days, zinc supplemented rats had twice the stimulation index of controls. Within 5 days, it was three times control. By 7 days it has returned to less than control. This suggested that zinc accelerates the proliferative response of effector T-cell lymphocytes which, in turn, could then accelerate and strengthen responses of antigen sensitized cytotoxic killer cells from the suppressor subset and other immune responses for the inactivation of viruses and tumors.

Plaque forming cell (PFC) responses to tumor cells in animals are significantly lower in zinc deficiency. A decrease in the number of helper or effector T-cells, or precursors of antibody forming cells or increased suppressor cell activity may be responsible for this observation. Studies are needed to ascertain the role of supplemental zinc in reactivating T-cell lymphocyte response to tumors. However, it is known that zinc increases the number of effector T-cells.

It has been demonstrated that it is possible for the immune system to eliminate large established tumors in mice by infusion of sensitized T-cells from immune donors but only when the tumors grow in thymectimized and T-cell-depleted recipients. These and other similar findings strongly suggest that the failure of the immune system to reject the immunogenic tumor is the result of the generation of suppressor T-cells and not cytotoxic killer cells.

Since the host immune response to a fetus is similar (or identical) to the host immune response to a tumor, an effect of zinc in stimulating effector T-cell function against tumors (fetuses) may have already been observed in animal pregnancy. Zinc supplements (100 mg zinc sulfate three times daily) during the third trimester of pregnancy resulted in three pre-mature births and one still-birth in four consecutive subjects. Other recent studies have presented data linking heightened suppressor cell function in human pregnancy (a known zinc deficient state) to lowered PFC response and splenic enlargement with suppressor cells. Similar PFC changes have been observed in animals under conditions of tumor growth.

Histamine is known to activate suppressor T-cells and to suppress the PHA proliferative response of effector T-cells. A minimum of 2 hours contact with histamine is required in order to activate suppressor cells. Maximum suppressor activity occurs in 18-24 hours, and is not increased thereafter. The suppression is dose-dependent. At a histamine concentration of 10-3M to 10-4M the suppression is equivalent to that suppression obtainable with Con A. It is well known that histamine mediates the allergic responses encountered in pre-leukemia as well as in other malignancies, atopic allergy, infections and upper respiratory viral infections. Consequently, zinc metabolism errors or gross zinc deficiency can directly damage effector T-cell responses to tumors, and indirectly damage effector T-cell responses to tumors through histamine inhibition of effector T-cells and activation of suppressor T-cells.

A number of chemically induced or transplanted animal tumors have been inhibited, prevented and/or eliminated by simultaneous administration of zinc. Woster found that it was necessary to administer zinc within two days of the administration of the tumor cells for zinc to be protective. Phillips and Sheridan have demonstrated that zinc injected intraperitoneally prevented tumor genesis in 50-70 percent of mice previously innoculated intraperitoneally with certain leukemic cell lines. Without zinc, all controls died from the same types of leukemic cells and dosage. According to Phillips, either zinc potentiated effector T-cell activity (specifically PFC function), or minimized the suppressor response, or induced T-cell immune interferon, or directly poisoned these cells or any combination thereof.

Recent studies in human interferon production point out that lymphoblastic transformations of T-cells is a necessary prerequisite to T-cell immune interferon production. Since other effector T-cell mitogens also induce interferon, the mitogenic property of zinc on effector T-cells suggests that interferon production results. Zinc without viral antigens has been demonstrated not to stimulate interferon production. Since there is a differential role for zinc between antigen and mitogen induced lymphokine production it is suspected that an antigen must be present before zinc can stimulate interferon production.

Several roles for zinc exist in the activation of T-cells. Zinc ions stimulate DNA synthesis of lymphocytes within a few days; at this time approximately 10%-40% of cells are transformed into lymphoblasts. Additionally zinc-8 hydroxyquinoline unsaturated complexes are stimulatory to animal lymphocyte mitosis, even though it is cytoplasmic membrane impermeable. Consequently at least two mechanisms exist for zinc to stimulate lymphocytes in some animal models.

In humans, one protein, transferrin, is vital to CMI in that only transferrin bound zinc is functional in the human T-cell lymphocyte. Since transferrin in the humanis only 30% iron saturated, substantial zinc transport capacity for immune function is normally available. Clearly, a nutritional deficit that induces a loss or significant reduction in transferrin synthesis would cause both anemia and primary immunodeficiency. Interferon and transferrin concentrations are reduced in those nutritional deficiencies, such as zinc, that interfere with protein synthesis.

In leukemia, transferrin levels are often very low. Giving zinc raises the transferrin serum level with a concurrent increase in lymphocyte transformation. Adding transferrin by transfusion results in stable and normalized transferrin serum levels but only when given in massive doses (20-30 mg/kg body weight/day) over a 14-day period. Lesser doses are rapidly eliminated from the blood, possibly by a LEM-like reaction where the liver removes zinc from the blood. Again, lymphocyte transformation is increased. In 1953 some remissions from acute lymphocytic leukemia occurred after giving large doses of zinc and/or zinc transferrin, although the number of subjects was too small to prove anything conclusive. During the course of treatment a simultaneous tendency to normalization of the number of blood cells and maturation of the peripheral blood also occurred.

Unfortunately, T-cell lymphocyte count, activity and function in infants, early childhood and in older people may be inadequate or absent. Alternatively, either cytotoxic or suppressor subset functions might be too low or too high resulting in imbalanced T-cell function, and predisposition to either immunodeficiency or auto-immune disease.

According to Robert Good, T-cell count and function change in humans after a period of zinc deprivation resulting in thymic involution. A dramatic breakdown in immunity follows, particularly helper T-cell and killer T-cell function as well as plaque-forming (PFC) response to tumors. Other antibody-related changes also occur. The unique sensitivity of the human thymus to zinc depletion may be related to the fact that terminal deoxyribonucleotidyl transferase is a zinc containing enzyme which is only found in the thymus and immature thymocytes. Zinc deficiency also causes other thymic related changes including a drastic reduction in a hormone (FTS) needed in the differentiation of precursor cells into Ø-positive lymphocytes.

Zinc can be used to improve age-associated immune dysfunction. When oral zinc supplementation (440 mg zinc sulfate) was given to institutionalized healthy people over 70 years old, there was significant improvement in the number of circulating T-cell lymphocytes, delayed cutaneous hypersensitivity reactions and immunoglobulin G (IgG) antibody response. Zinc had no effect on the number of total circulating leukocytes or lymphocytes or on the in vitro lymphocyte response to three mitogens including PHA, Con A, or PWM. Malignant disorders are often considered diseases of aging. It is highly probable that administration of zinc to the elderly (or any age group) who demonstrate reduced T-cell function will result in increased or even normalized resistance to tumor formation.

Obesity as well as nutritional deficiency in humans can adversely affect CMI and other immunological functions. In one test, zinc therapy for four weeks improved immunological responses in the subjects. Increased malignancy rates in obesity have been observed. It seems probable that zinc can be effective in reducing the malignancy rate in the obese population.

Since zinc is necessary for thymic function and effector T-cell function and effector T-cell function is necessary for many other immune functions, it is now somewhat clearer why zinc nutrition is important to immunological health. It is noteworthy to observe that the new-born human infant receives 70-900 mmg zinc per 100 gm colostrum, thus significantly changing the zinc/copper ratio and activating the infant's primary immune system. Perhaps zinc is truly nature's immune system switch.

In addition to zinc stimulation of effector T-cells, lithium is now being used to significantly minimize the leukocyte immunosuppression caused by some cancer chemotherapy drugs with a ten-fold reduction in infection, and even greater reduction in mortality. Mixtures of lithium, zinc and calcium have been shown to stimulate lymphocyte transformation to levels observed for lectin stimulation. Lithium appears useful in treating children with certain kinds of chronic neutropenia.

Although zinc is necessary for interferon production, extremely high amounts of zinc (10^{- 1}M and above) result in the prevention of interferon release when induced by the Sendai virus. It is suggested that the zinc interferes with the proteolytic cleavage of interferon before it is secreted. However, the possibility of zinc inhibiting viral polypeptide cleavage was not discounted. No change in interferon secretion was noted (either elevated or reduced) at zinc ion concentrations less than 10^-2M.

BODY ODOR -- FREE ASPARAGINE?

On occasion a strong and offensive body odor is emitted from a person prior to diagnosis of acute lymphocytic leukemia. The odor is thought to be that of an accumulation of free asparagine which is an essential amino acid for malignant cells by a nonessential amino acid for normal cells.

In experiments to ascertain whether zinc played a role in nucleic acid metabolism and protein synthesis, it was shown that for the microorganism EUGLENA GRACILIS, zinc deficiency would result in a marked decrease in protein and RNA content and an increase in free amino acids. The increase of amino acids is largely accounted for by glutamine and asparagine. The accumulation of these two amino acids suggest that they represent storage of excess nitrogen resulting from impaired protein synthesis. Similar results have been observed in plants.

Assuming that the molecular nature of unique biological activities is the same in all biological species, then zinc deficiency could also result in an accumulation of free asparagine in humans, and may explain the presence of high levels of free asparagine in pre-leukemia and leukemia.

L-Asparagine synthetase has been shown to be responsible for the resistance to L-Asparaginase in Acute Lymphocytic Leukemia. It is also present in many experimental tumors and in the normal mammalian pancreas. In one experiment, L-Asparagine synthetase was 90%-100% inhibited by zinc chloride at a 1 milliM concentration in vitro. Tests indicated that zinc interacted at the L-glutamine site on the enzyme. In vivo zinc experiments failed to affect the concentration of L-Asparagine although the test mice revealed necrotizing pancreatitis at a single dose rate of 100 mg/kg or when given daily at a dose rate of 20 mg/kg (Ref. 48). Other studies, primarily by Jerry Phillips, fail to substantiate the above statement related to necrotizing pancreatitis at the stated doses. This important experiment needs to be repeated.

OTHER

Growth suppression, decreased weight, skin changes, mental lethargy, apathy, depression, irritability, excessive fatigue, poor appetite, smell and taste alterations, palpable liver and spleen, thymic atrophy, diarrhea, malabsorption, steatorrhea and ophthalmic signs are a few of the other clinical manifestations of zinc deficiency. Most if not all of these symptoms have been observed in pre leukemia. No more than one or two may be observed in any one person or at any single time. In effect they can hardly be distinguished from many other routine childhood illnesses, and are not direct evidence of zinc deficiency.

The laboratory criteria for the diagnosis of zinc deficiency are not well established either. The response to zinc therapy is probably the most reliable index for making a diagnosis when considering the cause of such symptoms. Zinc serum levels have not been shown to always be a reliable indicator of zinc bioavailability. In fact, cases of acrodermatitis enteropathica, a lethal zinc deficiency disease, have been found with much higher than normal zinc serum levels, which returned to normal upon zinc supplementation.

Symptoms found in zinc deficiency may also be caused by enzyme or cellular malfunctions and by nucleic acid malfunctions. Over 90 enzymes have been identified wherein zinc is a necessary constituent, with 45 being involved in basic cellular reproduction. Zinc functions in these enzymes by maintaining spatial and configurational relationships. A number of these enzymes such as alkaline phosphatase are involved in cellular growth and are sensitive to zinc deficiency.

A few examples of zinc enzymes include: alcohol dehydrogenase, RNA polymerase, DNA polymerase, alkaline phosphatase, carboxypeptidase A and B, dipeptidase, aldolase, carbonic anhydrase, pyruvate carboxylase, and superoxide dismutase.

The precise relation of zinc to zinc deficiency symptoms remains to be determined in most cases.

Growth related problems and fatigue could be related to the role of zinc in protein synthesis, enzymes, and absorption. Mental and emotional problems could be related to zinc's role with histamine as a neurotransmitter in the hippocampusmossy fiber structure of the brain. A palpable spleen might be related to zinc deficiency induced increase in spleen seeking suppressor T-cell lymphocytes (Ref. 21). Thymic atrophy could result due to the basic nutritional need for zinc by the thymus. Zinc is a functional part of the retina and is helpful in treating cataracts of the elderly. Acne and other skin problems can be a zinc deficiency. Zinc is very helpful in alleviating acne. Diaper rash often dramatically responds to zinc oxide lotion.

As more information about the clinical hallmarks of the zinc deficiency syndrome is understood, the following are currently believed to be markers of zinc deficiency: hypozincemia, iron deficiency anemia, hepatosplenomegaly, growth retardation, arrested sexual maturation, partial adrenal insufficiency, anorexia, dryness and hyper pigmentation of the skin, impaired taste and smell acuity, delayed wound healing, sub optimal growth, poor appetite, pica, impaired immune response. Diseases that are known to be associated with zinc deficiency include malignancy and many other diseases.

The role of zinc deficiency or improper zinc metabolism has been established as possibly being causal in the conditions found prior to the actual development of ALL, and suggests that zinc depletion may present a stage for leukemia, by decreasing natural resistance to leukemia, by increasing the amount of free asparagine, by increasing corticosteroid levels, and by allowing lymphocyte genetic requirements for zinc to go unmet. Zinc deficiency in the leukemic process itself can also be demonstrated.

ZINC CONTENT OF LEUKEMIC BLOOD

Leukemic cells contain only about 10% of the zinc contained in normal lymphocytes. Plasma zinc concentrations are lower and plasma copper concentrations are higher in children with untreated ALL than in the same children after successful treatment or healthy children. Zinc transferrin is also low in many cases of leukemia. In one case of acute myelogeneous leukemia, zinc deficiency was so severe that acquired acrodermatitis enteropathica developed. In several cases of ALL, zinc deficiency symptoms developed. Remarkably rapid elimination of zinc deficiency symptoms and greatly increased tolerance to the chemotherapy occurred with zinc. The DNA of CCRF-CEM human leukemia cells contain one-fourth of the zinc of normal lymphocyte DNA. RNA from leukemic cells, however, contained nearly four times the zinc of control RNA. Histone, from leukemic cells, which is known to be involved in the regulation of gene expression, only contain one-fourth of the zinc content as is contained in control histone. Consequently, zinc depleted histone fractions could alter the interaction of histones with DNA and as a consequence alter gene activity. The nucleus of human chronic lymphocytic leukemia cells contain only one-third the zinc of normal cells. The cytoplasm of human chronic lymphocytic leukemia cells contain only one-third to one-fifth the zinc of normal cells. Phillips found that leukemic lymphocytes incorporate transferrin bound zinc more slowly and to a lesser extent than do normal lymphocytes. In addition, he found that normal lymphocytes respond to increased intracellular zinc by synthesizing a low molecular weight protein, possibly a metallothionein, while lymphocytes from donors with chronic lymphocytic leukemia fail to synthesize this intracellular zinc-binding protein. It is well known that excessive zinc excretion and low level of serum zinc occur in leukemia.

Zinc is necessary for proper regulation of prostaglandins as well as being antagonistic to calcium. In leukemia, and malignancy in general, cellular prostaglandin levels are distorted resulting in cell membrane fluidity, rigidity or other functional alterations. Calcium metabolism is unregulated, and no control over cytoplasm calcium can be established thus resulting in undesired cellular division. These differences along with impaired primary immune functions and other biological activities are suggested to be reversible or controllable when certain nutrients including zinc and gamma linolinic acid necessary for prostaglandin and calcium regulation are supplemented in a sufficient amount and in a biochemically available form. The only known exogenous source of gamma linolinic acid is the evening primrose oil.

GENETICS AND ZINC

Zinc is necessary for all growth. In its absence all growth, including malignant growth, is not possible.

As early as 1949, differences in zinc metabolism of normal and leukemic lymphocytes first gave rise to the postulate by Vallee and Gibson that the disturbance of a zinc-dependent enzyme is critical in the patho-physiology of myelogenous and lymphatic leukemia as well as lymphoma, Hodgkin's disease and multiple myeloma. Data obtained since 1949 bear out the 1949 postulate that zinc is involved in nucleic acid metabolism and that zinc deficiency bears importantly on the lesions observed in leukemia and other conditions. Experiments using ethylenediamine tetraacetate (EDTA) and other metal chelators to chelate metals within DNA and DNA polymerase result in functional inhibition of their activity which can be reversed only by adding Zn2+ in the growth medium. The same results occur for terminal deoxynucleotidyl transferase, DNA-dependent RNA polymerase and thimidine kinase from several species. Direct evidence that the RNA-dependent DNA polymerase--a reverse transcriptase--from avian myeloblastosis virus is a zinc metalloenzyme has been obtained. Zinc is the only mineral present in this enzyme. Inhibition of RNA-dependent DNA polymerase by zinc chelation brings about both an instantaneous reversible inhibition and a time-dependent irreversible inhibition. Zinc also regulates the activity of RNase, thus the catabolism of RNA also appears to be zinc dependent.

Studies such as these establish the importance of the role of zinc in the formation of DNA from RNA templates and extend previous findings that zinc is necessary in the formation of RNA and DNA from DNA templates.

It is still not clear at all why zinc deficiency in genetic material causes such molecular instability and dysfunction. There must be a relationship between zinc deprivation and the malfunction of molecular systems based upon zinc metalloenzymes.

In terms of enzyme sensitivity to zinc deficiency three enzymes -- alkaline phosphatase, carboxydeptidase and thimidine kinase -- appear to be most sensitive to zinc restriction in that their activities are affected adversely within three to six days of institution of a zinc-deficient diet in experimental animal.

Additionally, it has been demonstrated that zinc may be necessary for all phases of cell growth. Zinc was required for cells to pass from the G1 phase into S, from S to G2 and from G2 to mitosis. It is tempting to suggest that the proliferation of blasts in leukemia is solely due to those cells being stuck in an early stage of development simply due to an intracellular deficiency of zinc or zinc metabolism errors. However, in zinc deprived rats the mast cell population of the tibia bone marrow became increasingly higher than in controls. It was also noted that zinc deficiency was responsible for the accumulation of mast cells which were incapable of completing their maturation. In view of the general growth depressing effects of zinc deficiency, it is difficult to imagine the accumulation of mast cells in the bone marrow as the result of any known growth stimulating phenomena. It was suggested as being possible to consider zinc as a factor in the differentiation and release of the mast cells.

Upon consideration of the human leukocyte antigen (HLA) system, the amelioration of some diseases related to A1 and A2 have been demonstrated to be possible with zinc. Hayfever, and asthma (A1) and primary immunodeficiency (A2) can be ameliorated by zinc when supplemented at the rate of 1-2 mg/pound/day . Recurrent Herpes (A1) can be eliminated with topical zinc application. If the genetic markers A1 and A2 denote a genetic need for increased dietary zinc, then a number of other diverse HLA-A1 and A2 associated diseases (and perhaps A3 and A10 diseases) might be ameliorated by zinc in much the same way as pernicious anemia (B7) can be ameliorated by supplemental Vitamin B-12.

As stated in Part I, a major reason for conducting this review was to determine if any supplemental nutrient could positively influence the chemotherapeutic agents used in CCG protocol 161 regimen 2. In this protocol, predisone, vincristine, L-asparaginase, and intrathecal methotrexate are used for remission induction followed by 2400 rads cranial radiation. Maintenance therapy calls for use of vincristine and predisone on a monthly "pulse" basis, methotrexate weekly and 6-mercaptopurine daily.

This protocol results in the depletion or inactivation of niacin, vitamins B-6, C, D, and folic acid, as well as zinc, calcium, potassium and nitrogen. Of these only folic acid is known to be intentionally depleted. Replacement of the other nutrients may be beneficial to normal health, however only replacement of zinc had even a theoretical possibility of influencing the performance of any of the drugs used in this protocol, according to the literature reviewed.

ZINC/L-ASPARAGINASE

Zinc may be important as a dietary supplement at the rate of 1 - 1 1/2 milligram zinc per pound of body weight in the treatment of ALL using protocols containing L-asparaginase.

L-asparaginase contains the enzyme L-asparagine amidohydrolase which destroys the amino acid asparagine. Leukemic cells are dependent upon an exogenous source of asparagine for survival. Normal cells, however, are able to synthesize asparagine and are thus affected less by the rapid depletion produced by L-asparaginase. Depletion of asparagine is a unique approach to therapy of ALL based upon a clear metabolic difference between leukemic lymphocytes and normal lymphocytes. Linus Pauling writes in his book "VITAMIN C AND CANCER" about L-asparaginase: "Theoretically the perfect anti-cancer drug, exploiting one clear biochemical dissimilarity between normal and malignant cells."

It has been demonstrated that zinc deficiency in bacteria and plants produces accumulations of the free amino acid asparagine, which is believed to represent storage of excess nitrogen resulting from impaired protein synthesis.

Since many similarities at the molecular level exist between the species; it is reasonable to suggest, at least in the absence of clear proof to the contrary, that zinc deficiency induces free asparagine accumulation in human tissue. Zinc deficiency is known to exist in leukemia. The result is that this mineral deficiency, theoretically at least, competes with L-asparaginase by stimulating L-asparagine synthetase thus replenishing free asparagine. L-asparaginase is only effective when new asparagine is not being released, or is being released at a rate commensurate with the dose, frequency and duration of therapy with L-asparaginase.

Consequently, the supplementation of zinc should theoretically improve the effectiveness of L-asparaginase in the management of malignant disorders even though in vivo animal studies disagree.

In the case of the child with ALL where 50 mg. of zinc was given daily and coterminous with L-asparaginase, bone marrow blast count went from 95+% to an observed count of zero blasts in less than 14 days. This is the only known humans case of augmentation of L-asparaginase with zinc. Since bone marrow improvements normally obtained by 85-90% of patients with ALL on similar protocols still contain 3-5% blasts after 30 days in a M-1 remission, these results, as far as can be determined, are completely unique in the management of ALL. It is also significant since the rate in which a remission is obtained, as well as the reduction in blast count, has been demonstrated to be related to the propensity to relapse.

L-asparaginase has been observed to be highly toxic to the liver and capable of inducing anaphylactic shock. Zinc, to the contrary, has been shown to have a protective influence from toxic substances, such as carbon tetrachloride, on the liver and reduces or prevents anaphylactic shock through its mast cell regulatory role in Type I allergy and its stabilizing effect on all cell plasma membranes. No adverse reactions of any kind were noted in the first test of zinc as an adjunct to L-asparaginase in the 3-year-old girl. Additionally, in the absence of information in the literature to indicate harm by zinc, other tests of zinc in the amplification of the effectiveness of L-asparaginase seem both reasonable and necessary, if not given in great excess in order to eliminate or minimize pancreatic injury.

NOTE: Consider L-asparaginase as "a mop to pick up asparagine from a leaky faucet, while zinc turns off the faucet!" This combination in some form is probably the cure for all cancers, although tumor death products may be toxic to normal cells.

ZINC/PREDISONE

The action of predisone against leukemic lymphocytes involves the diminution of glucose and amino acid transport into the cell, phosphorylation and thymidine incorporation. So long as the cell line retains the cytoplasmic receptors for glucocorticoids, the cell is susceptible to cytolysis in response to steroids. Corticosteroids increase urinary excretion of zinc and decrease serum zinc, (Important!) Hyperfunction of the adrenal cortex, with a release of cortisone accompanies zinc deficiency. It is known that catabolism due to infection results in glucocorticoid release and negative zinc balances. In protein-energy malnutrition of children, thymic atrophy of stress is believed to be mediated by high levels of circulating corticosteroids. Zinc supplementation causes thymic regrowth in children recovering from protein-energy malnutrition, whereas a normal high energy diet does not cause thymic regrowth. Altering the corticosteroid/zinc relationship by supplementing zinc relieved cell mediated immunity and humoral immunity problems in these children, as zinc also stimulates both lymphocyte function and cell mediated immunity. Excessive zinc excretion occurs in leukemia suggesting high corticosteroid levels and consequent immunosuppression.

In the case of the child who was administered zinc in conjunction with predisone, no adverse reactions were encountered. Total white blood cell count averaged 4000/mm3 and varied between 2000/mm3 and 7000/mm3 on infrequent occasions. Absolute lymphocyte count averaged 1400/mm3 until chemotherapy was increased due to weight and height gain. Afterwards, ALC remained at 1000/mm3 or less. Moonface appearance and obesity normally found with use of predisone were absent. Immunity to diseases appeared normal in that the incidence of infection became much lower after initiation of chemotherapy with zinc than during an equivalent period prior to diagnosis. Atypical or activated lymphocytes were noted in 12% of the bi-weekly blood tests. Growth was accelerated after initiation of chemotherapy and zinc. A "catch-up" growth occurred from preleukemic height and weight of 28% and 5% respectively to 50% and 50% respectively after one year of treatment for ALL and use of zinc throughout the third year, growth has remained at the 50% level for both height and weight with only minor variations. In general the child enjoys excellent health and is very strong.

In studying the immunostimulatory effect of zinc in patients with ALL in Poland, researchers in 1978 added to the above observations. They found that, with drug protocols very similar to CCG 161 that the effect of zinc was statistically significant in enhancing T-cell mediated immunity, raising TEa5' percentage from 22.3 to 32.4 and absolute number of TEt60' from 338.8 to 517.2. No change in IgG, IgA, IgM or total gamma globulins occurred. A slight decrease in granulocyte count was the only adverse side effect noted. And it was not considered statistically significant.

Dental caries are predicted in zinc deficiency. Since zinc deficiency is often caused by use of predisone it is often found that dental caries accompany ALL while undergoing treatment with predisone. In this case, no dental caries formed, and dental health remained excellent, with 4 adult teeth forming normally within the 3 years of treatment.

Bone marrow blast count has remained completely stable at 0.2% for three years of therapy. During a one-month period after 24 months of therapy when therapy was discontinued in order to administer chicken-pox vaccine, bone marrow blast count only rose to 2%, and then returned to 0.2% upon resumption of chemotherapy.

Experiments as early as 1973 by Bruce Korant have clearly demonstrated the ability of zinc to act as a replication inhibitor for certain viruses. In the rhinoviruses, zinc's effects are to block polypeptide cleavage. Addition of only 0.2mM zinc prevents post-translational cleavages and causes the accumulation of a set of large precursor polypeptides. Different cleavages were sensitive to different concentrations of zinc, and progressively larger polypeptides could be accumulated by increasing the zinc concentration. The addition of zinc at any time during viral replication immediately inhibited further formation of infectious virons. A number of other metals were also tested but only zinc displayed antiviral activity in non-toxic concentrations. Eight out of nine rhinoviruses tested were sensitive to zinc at 0.1mM concentrations. Only rhinovirus type 5 was resistant. Added zinc is bound to capsids of rhinoviruses and prevents them from forming crystals. Zinc complexes with rhinovirus coat proteins and alters them so that they cannot function as substrates for proteases or as reactants in the assembly of virus particles. The zinc ion is an inhibitor of virus production and blocks protein cleavage of rhinovirus, enterovirus, and cardiovirus precursors. Zinc ion blocks viral maturation of coxsackievirus. If zinc ions were present at the start of rhinovirus infection (in vitro) the virus could do little harm to cellular translation, thus host protein synthesis was spared if viral proteins were not synthesized and normally processed. Many other viruses, including Herpes Simplex 1 and 2, encephalomyocarditis, foot-and-mouth, enterovirus 70, vaccinia and some other viruses have also been demonstrated in vitro and IN VIVO to be highly susceptible to destruction by zinc at non-toxic levels. Korant, in addition, indicates that recent evidence for polypeptide cleavages during the replication of bacteriophages, and many animal viruses including RNA tumor viruses suggests a role for protease inhibitors, including zinc, in blocking certain stages of replication of many viruses.

Observing that zinc inhibits the formation of tumors in animals and kills human leukemia (ALL) cells with other metal containing drugs such as CIS-platinum it is plausible to suggest that these cells were driven by RNA-tumor viruses that were controllable by zinc.

It is well known that viruses cause immunosuppression of their host in order for them to survive. Perhaps the RNA tumor virus causes the long term depletion of serum zinc in a manner similar to that resulting from bacterial infections or endotoxin reactions involving LEM and the liver. If that occurs, zinc depletion could result in long lasting immunosuppression favorable to the survival of zinc intolerant viruses such as the proposed RNA-tumor viruses. Fever is often associated with pre leukemia, and may indicate a period of time consistent with LEM production as a precursor event to frank leukemia. Administration of aspirin at the time of this type of fever could stimulate viral proliferation through increased immunosuppression, and could theoretically promote leukemia.

Additional evidence has been acquired that zinc can control virus activated tumor cells in that SV40-transformed human cells fail to grow in zinc concentrations which permit normal human fibroblasts to proliferate (2^-3 x 10^-4M. The only difference between the cells was viral infection by an oncogenic virus.

Structural protein synthesis in the avian myeloblastosis virus have been shown to be preventable by exposure of intact cells to 10mM (10-2M) concentrations of zinc ions which is 100 times the concentrations necessary for control of rhinoviruses.

Zinc is a vital constituent of red blood cells. Red blood cells contain 6 to 8 times the amount of zinc as blood plasma, which is around 100 mg/dl (microgram/deciliter). Most (75%-85%) of zinc in the blood is associated with carbonic anhydrase of the erythocytes. Zinc inhibits the formation and transformation of red blood cells into ghosts by certain hemolytic reactions of the complement system (C-9), while most zinc in cells is used to stabilize cell plasma membranes against viral infection, toxins, amd complement.

Only platelets in the human require more zinc than mast cells or basophils.

White blood cells contain up to 25 times the amount of zinc in the serum. Mast cells and basophils contain extremely high amounts of zinc, being found in granules with histamine. Zinc inhibits macrophage mobility and phagocyte activity yet potentiates macrophage viability. Zinc deficiency results in maximum macrophage mobility. The effects are reversible and are believed to be due to a role of zinc on the cell's membrane. The overall regulatory control of zinc blood level is by the liver. Certain soluble factors, called leukocytic endogenous mediators (LEM), are released by activated leukocytes or macrophages during an acute inflammation of a bacterial origin or endotoxemia. They cause a sequestering of plasma zinc and iron by the liver within hours, accompanied by a potentiation of phagocytic function even when zinc is given at the 1-2 mg zinc/pound rates. An endogenous pyrogen (EP) is also released by phagocytizing white cells at the same time with a resultant increase in body temperature. Hyperthermia has been shown to potentiate the immune response. It may be that the sequestering of zinc by the liver for protracted periods in bacterial infections could result in thymic atrophy and diminished T-cell function and count.

A significant fall in plasma zinc levels is noted in the third trimester of human pregnancy. Similar plasma zinc level reductions occur in malignant disorders. A triple purpose may be served by these changes: (1) fetal or tumoral uptake of zinc occurs, (2) diminished cell mediated immunity to the fetus or tumor (particularly PFC) occurs, and (3) leukocyte mobility enhancement occurs.

Zinc may be sequestered by tumors from body stores, primarily the liver and bone, to fulfill their metabolic needs. A consequent and deepened immunosuppression may occur if accompanied by an inadequate dietary intake of zinc. Tumor growth rate has not yet been shown to be accelerated when zinc is supplemented sufficiently to meet other body requirements such as T-cell and thymic requirements.

It has long been known that intestinal zinc and iron absorption is reduced in bacterial infections and endotoxemia presumably to simplify the function of the liver in starving the bacteria. Intestinal zinc absorption is enhanced in many but not all viral infections, presumably to impede viral growth.

Zinc aids in Vitamin A absorption. Vitamin A deficiency has been liked to malignant disorders. Could increased zinc intake in the general population aid in raising Vitamin A serum levels and reduce the cancer rate?

Zinc as a trace mineral is second only to iron in abundance in humans. Its role in human metabolism is not yet totally known. Even the mechanism of zinc absorption is poorly understood. Zinc deficiency to the T-cell lymphocyte system and thymus may occur from a number of sources including inadequate dietary intake, faulty absorption across the intestinal mucosal membrane, inadequate or faulty albumen binding, inadequate cellular uptake, competition from other metals such as calcium, dietary chelation by phylates, from whole wheat and other dietary fiber, excessive soy bean intake, diarrhea, inadequate pancreatic function, faulty transferrin synthesis, and loss through catabolism from stress and infection.

Low consumption of animal protein, geophagia, parasitic infestation, hemolysis, blood loss, high intake of dietary fiber, alcoholism, liver disease, malabsorption, renal diseases, burns, pregnancy, oral contraceptives, penicillamine therapy, poor appetite, chronic debilitation, Crohn's disease, cystic fibrosis, sickle cell anemia, malignancy, sweating, excessive consumption of food products process with EDTA or other metal chelators (used to prevent spoilage), poisoning by heavy metals such as lead and cadmium, and starvation are often accompanied by zinc deficiency. In many other diseases zinc deficiency occurs for various reasons. Some are mentioned elsewhere in this report.

One writer found that it was difficult to find a stimulus to zinc absorption. Zinc is primarily absorbed and excreted through the intestines. Increased urinary zinc excretion occurs as a consequence of a number of conditions including leukemia and other malignancies, starvation and surgery. It has been suggested that urinary zinc may provide an index by which to measure muscle catabolism.

Surgery has been shown to occasionally cause a permanent disturbance to zinc metabolism, unless 1 to 5 mg zinc/pound body weight is administered during and after (several days to several months) healing process.

In the case of growing children, competition for zinc is so intense and the opportunities for zinc deficiency so numerous that normal dietary zinc intake may be quite inadequate to supply all of the growing child's needs. The result being that faulty cell mediated immunity and excessive mast cell degranulation occur with an increase in viral illnesses, allergy, and malignancy, along with failure of other zinc dependent functions such as growth.

Still, no specific zinc linkage has been established that actually explains the occurrence of malignant transformations. However, it would be of interest to conduct studies using low level radiation on normal blast cells in vitro deprived of zinc transferrin compared with cells replete with zinc transferrin. Such studies have not been done although a similar study with no direct attention to zinc bioavailability using carefully nourished mouse fibroblasts found an extraordinarily higher cell transformation rate than had ever been previously expected from low level dental and medical diagnostic X-rays. One out of every 10,000 cells was malignantly transformed (Ref. 41). It is important to know if any washing was done with a metal chelator such as EDTA. If so, the zinc in the genetic material could have been so depleted so as to allow the cells to be defenseless against cellular transformation induced by low level radiation or other ionizing sources. This important experiment should be repeated paying careful attention to the role of zinc in the genetics of the cells.