Zinc is a natural constituent of soil and is second only to iron as a metal naturally present in the human body. The National Research Council has established a Recommended Dietary Allowance (RDA) of 30 mg of zinc for human consumption. Colloidal zinc can be made by anyone using our domestic, commercial or indanoparticles in 24 hours.
Zinc is antimicrobial and inhibits the proliferation of many viruses, moss, fungus, algae and mildew. The body contains 2 to 3 g of zinc (Zn), found mainly in bones, teeth, hair, skin, liver, muscle, leukocytes, and testes. One third of the 100 µg/dL (15.3 µmol/L) of zinc found in plasma is attached loosely to albumin, and about 2/3 is firmly bound to globulins. There are > 100 zinc metalloenzymes, including a large number of nicotinamide adenine dinucleotide (NADH) dehydrogenases, RNA and DNA polymerases, and DNA transcription factors as well as alkaline phosphatase, superoxide dismutase, and carbonic anhydrase.
Dietary intake of zinc by healthy adults varies from 6 to 15 mg/day, and absorption is about 20%. Good sources of zinc include oysters, meat, eggs, seafood, black-eyed peas, tofu, and wheat germ. The RDA is 0.2 mg/kg/day for adults.
Uses for zinc:
- Donates free electrons due to its antioxidant function
- Promotes healthy skin
- Supports healthy cartilage regeneration
- Promotes cellular metabolism and anti-aging benefits
- Supports hormonal balance
- Essential for a healthy immune system
What Does Zinc Do?
A small, preliminary trial has found zinc sulfate to be effective for contact dermatitis (a skin rash caused by contact with an allergen or irritant).11 Participants with active skin rashes took approximately 23 mg of zinc (in the form of zinc sulfate) three times daily, for one month. 73% of those taking the zinc sulfate had complete resolution of their skin rashes, while the remaining participants had a 50-75% improvement.
Zinc is a component of more than 300 enzymes needed to repair wounds, maintain fertility in adults and growth in children, synthesize protein, help cells reproduce, preserve vision, boost immunity, and protect against free radicals, among other functions.
Zinc reduces the body's ability to utilize the essential mineral copper. (For healthy people, this interference is circumvented by supplementing with copper, along with zinc.) The ability to interfere with copper makes zinc an important therapeutic tool for people with Wilson's disease, a genetic condition that causes copper overload.
Zinc supplementation in children in developing countries is associated with improvements in stunted growth, increased weight gain in underweight children, and substantial reductions in the rates of diarrhea and pneumonia, the two leading causes of death in these settings.8 910
Zinc may be of benefit in the care and treatment of the following conditions:
Childhood intelligence (for deficiency)
Common cold/sore throat (as lozenges)
Infertility (male) (for deficiency)
Night blindness (for deficiency)
Wound healing (oral and topical)
Anemia (for thalassemia if deficient)
Birth defects prevention
Canker sores (for deficiency only)
Celiac disease (for deficiency)
Cold sores (topical)
Common cold (as nasal spray)
Diabetes (preferably for those with a documented deficiency)
Gingivitis (zinc plus bloodroot toothpaste)
Halitosis (zinc chloride rinse or toothpaste)
Hepatitis C (zinc-L-carnosine)
Immune function (for elderly people)
Liver cirrhosis (for deficiency)
Sickle cell anemia
Skin ulcers (oral and topical zinc)
Sprains and strains (if deficient)
Tinnitus (for deficiency only)
Benign prostatic hyperplasia (BPH)
Dermatitis herpetiformis (for deficiency)
Ear infections (recurrent)
Zinc deficiencies are quite common in people living in poor countries. Phytate, a substance found in unleavened bread (pita, matzos, and some crackers) significantly reduces absorption of zinc, increasing the chance of zinc deficiency. However, phytate-induced deficiency of zinc appears to be a significant problem only for people already consuming marginally low amounts of zinc.
Even in developed countries, low-income pregnant women and pregnant teenagers are at risk for marginal zinc deficiencies. Supplementing with 25-30 mg per day improves pregnancy outcome in these groups.12 13 People with liver cirrhosis appear to be commonly deficient in zinc.14 This deficiency may be due to cirrhosis-related zinc malabsorption.15People with Down's syndrome are also commonly deficient in zinc.16 Giving zinc supplements to children with Down's syndrome has been reported to improve impaired immunity17 and thyroid function,18 though optimal intake of zinc for people with Down's syndrome remains unclear. Children with alopecia areata (patchy areas of hair loss) have been reported to be deficient in zinc.19 20
The average diet frequently provides less than the Recommended Dietary Allowance for zinc, particularly in vegetarians. To what extent (if any) these small deficits in zinc intake create clinical problems remains unclear. Nonetheless, a low-potency supplement (15 mg per day) can fill in dietary gaps. Zinc deficiencies are more common in alcoholics and people with sickle cell anemia, mal-absorption problems, and chronic kidney disease.21
The signs and symptoms of zinc deficiency include anorexia, growth retardation, delayed sexual maturation, hypogonadism and hypospermia, alopecia, immune disorders, dermatitis, night blindness, impaired taste (hypogeusia), and impaired wound healing. The first signs of zinc deficiency in marginally nourished children are suboptimal growth, anorexia, and impaired taste. Biochemical signs associated with zinc deficiency include decreased levels of plasma zinc (< 70 µg/dL [< 10.7 µmol/L]), alkaline phosphatase, alcohol dehydrogenase in the retina (which accounts for night blindness), and plasma testosterone as well as impaired T-lymphocyte function, decreased collagen synthesis (resulting in poor wound healing), and decreased RNA polymerase activity in several tissues.
Clinical assessment of mild zinc deficiency is difficult because many of the signs and symptoms are nonspecific. Nonetheless, if a malnourished person has a borderline-low plasma zinc level, is subsisting on a high fiber and phytate diet containing whole-grain bread (which reduces zinc absorption), and has reduced taste sensitivity, an impaired lymphocyte response to mitogens, and reduced gonadal hormone function, then zinc deficiency should be suspected, and treatment with zinc supplements (15 to 25 mg/day) should be tried.
Maternal zinc deficiency may cause anencephaly in the fetus. Secondary deficiency occurs in liver disease, in malabsorption states, and during prolonged parenteral nutrition. Night blindness and mental lethargy may be features.
Exercising Caution with Zinc consumption:
Zinc intake in excess of 300 mg per day has been reported to impair immune function.22 In topical form, zinc has no known side effects when used as recommended.
Preliminary research had suggested that people with Alzheimer's disease should avoid zinc supplements.24 More recently, preliminary evidence in four patients actually showed improved mental function with zinc supplementation.25 In a convincing review of zinc/Alzheimer's disease research, perhaps the most respected zinc researcher in the world concluded that zinc does not cause or exacerbate Alzheimer's disease symptoms.26
Is Zinc Toxic?
Zinc is only toxic to fungus type organisms (fungus, moss, algae and mildew). Zinc is not toxic to anything else - humans, animals, plants and fish are not affected in any way. Ingesting zinc in large amounts (200 to 800 mg/day), usually by consuming acidic food or drink from a galvanized container, can cause vomiting and diarrhea. Doses of zinc ranging from 100 to 150 mg/day interfere with copper metabolism and cause hypocupremia, RBC microcytosis, and neutropenia. Metal fume fever, also called brass-founders' ague or zinc shakes, is an industrial hazard caused by inhaling zinc oxide fumes; it results in neurologic damage.
Zinc Fights Off Pneumonia:
Pneumonia is a leading cause of mortality and morbidity in children less than five years old. Zinc is reported to prevent pneumonia, and to prevent and treat diarrhoea, and it may boost the body's immune response to infection.
W Abdullah Brooks and colleagues from the International Centre for Diarrhoeal Disease Research, Bangladesh, investigated whether zinc would help children between 2 and 23 months old with severe pneumonia. 270 children were randomly assigned to receive 20 mg zinc per day, or a placebo, in addition to standard hospital antibiotics.
Children given zinc recovered from severe pneumonia an average of one day earlier than did those given placebo, and their average stay in hospital was one day shorter. The zinc supplement was safe and well tolerated. Since a course of zinc treatment costs only US$0·15, and one day in the study hospital costs US$25, the potential cost savings are substantial.
Dr Brooks comments: "The effects on treatment failure are striking, have significant implications for reduction of antimicrobial resistance by decreasing multiple antibiotic exposures, and could help reduce complications and death in situations where second line drugs are not available."
Zinc Ions Protect Against SARS:
Dr George Rowland, a British immunologist and biochemist based in South Africa and an authority on zinc ion technologies, believes that zinc ions may prove of benefit in the SARS crisis.
Dr Rowland believes that the fact that SARS is caused by a coronavirus, related to a group of viruses causing the common cold, may be of considerable significance because there is evidence that zinc ions provide a natural protective mechanism against viruses, especially those causing respiratory tract infections. Over the past 30 years, researchers have demonstrated the critical role of zinc in diverse physiological processes, such as growth and development, maintenance and priming of the immune system, and tissue repair.
Dr Rowland writes: “Direct antiviral effects of zinc ions have been demonstrated against rhinoviruses responsible for the common cold and the role of zinc in the respiratory epithelium has recently come under scrutiny. Zinc has also been shown to directly decrease the incidence of respiratory infections in young children in developing countries, probably by mechanisms that involve restoration of T-cell immunity lost as a result of deficiency of this mineral.
Dr Rowland says: “When released in the vicinity of the oral mucous membranes, zinc ions can protect cells from attack by viruses such as rhinoviruses. It is believed that zinc ions attach to cell surface receptors thereby blocking viral attachment and uncoating. Whilst there is no evidence that attachment of the coronavirus causing SARS can be blocked by zinc ions, they are thought to help repair microscopic holes punched in cell membranes by viruses.
International Zinc Association
Articles, Scientific Papers, Press Releases and more on Zinc
Zinc Helps Fight Infection and Inflammation Boosting the Body’s Immune Response
Zinc Can Combat Childhood Killers
Zinc Found Critical Within The Brain to Improve Memory and Cognition
Galvanizers Join Global Zinc Effort for Kids
Unchecked Inflammatory Response Quelled By Zinc
Shedding Light On How Zinc – Essential To The Growth of All Living Organisms – Enters Cells
Zinc Deficiency is a Global Concern
Zinc Deficiency in Children with Dyslexia: Concentrations of Zinc and other Minerals in Sweat and Hair
Mossad SB, Macknin ML, Medendorp SV, et al. Zinc gluconate lozenges for treating the common cold. Ann Intern Med 1996;125:81-8.
Anonymous. Zinc lozenges reduce the duration of common cold symptoms. Nutr Rev 1997;55:82-8 [review].
Garland ML, Hagmeyer KO. The role of zinc lozenges in treatment of the common cold. Ann Pharmacother 1998;32:93-69 [review].
Macknin ML, Piedmonte M, Calendine C, et al. Zinc gluconate lozenges for treating the common cold in children. A randomized controlled trial. JAMA 1998;279:1962-7.
Eby G. Where's the bias? Ann Intern Med 1998;128:75 [letter].
Garland ML, Hagmeyer KO. The role of zinc lozenges in treatment of the common cold. Ann Pharmacother 1998;32:63-9 [review].
Weismann K, Jakobsen JP, Weismann JE, et al. Zinc gluconate lozenges for common cold. A double-blind clinical trial. Dan Med Bull 1990;37:279-81.
Bhutta ZA, Black RE, Brown KH, et al. Prevention of diarrhea and pneumonia by zinc supplementation in children in developing countries: pooled analysis of randomized controlled trials. Zinc Investigators' Collaborative Group. J Pediatr 1999;135:689-97.
Umeta M, West CE, Haidar J, et al. Zinc supplementation and stunted infants in Ethiopia: a randomised controlled trial. Lancet 2000;355:2021-6.
Gibson RS. Zinc supplementation for infants. Lancet 2000;355:2008-9.
Santucci B, Cristaudo A, Mehraban M, et al. ZnSO4 treatment of NiSO4-positive patients. Contact Dermatitis 1999;40:281-2.
Cherry FF, Sandstead HH, Rojas P, et al. Adolescent pregnancy: associations among body weight, zinc nutriture, and pregnancy outcome. Am J Clin Nutr 1989;50:945-54.
Goldenberg RL, Tamura T, Neggers Y, et al. The effect of zinc supplementation on pregnancy outcome. JAMA 1995;274:463-8.
Scholmerich J, Lohla E, Gerok W. Zinc and vitamin A deficiency in liver cirrhosis. Hepatogastroenterology 1983;30:119-25.
Karayalcin S, Arcasoy A, Uzunalimoglu O. Zinc plasma levels after oral zinc tolerance test in nonalcoholic cirrhosis. Dig Dis Sci 1988;33:1096-102.
Stabile A, Pesaresi MA, Stabile AM, et al. Immunodeficiency and plasma zinc levels in children with Down's syndrome: a long-term follow-up of oral zinc supplementation. Clin Immunol Immunopathol 1991;58:207-16.
Bjrksten B, Back O, Gustavson KH, et al. Zinc and immune function in Down's syndrome. Acta Paediatr Scand 1980;69:183-7.
Bucci I, Napolitano G, Guiliani C, et al. Zinc sulfate supplementation improves thyroid function in hypozincemic Down children. Biol Trace Elem Res 1999; 67;257-68.
Wollowa F, Jablonska S. Zinc in the treatment of alopecia areata. In: Kobori Y, Montagna W (eds). Biology and Diseases of the Hair. Tokyo: University Park Press, 1976, 305.
Lutz G. The value of zinc in treatment of alopecia areata. 2nd Meeting of the European Hair Research Society, Bologna, April 14, 1991..
Prasad A. Discovery of human zinc deficiency and studies in an experimental human model. Am J Clin Nutr 1991;53:403-12 [review].
Chandra RK. Excessive intake of zinc impairs immune responses. JAMA 1984;252:1443.
Shannon M. Alternative medicines toxicology: a review of selected agents. Clin Toxicol 1999;37:709-13
Bush AI, Pettingell WH, Multhaup G, et al. Rapid induction of Alzheimer A8 amyloid formation by zinc. Science 1994;265:1464-5.
Potocnik FCV, van Rensburg SJ, Park C, et al. Zinc and platelet membrane microviscosity in Alzheimer's disease. S Afr Med J 1997;87:1116-9.
Prasad AS. Zinc in human health: an update. J Trace Elem Exp Med 1998;11:63-87.
Broun ER, Greist A, Tricot G, Hoffman R. Excessive zinc ingestion-a reversible cause of sideroblastic anemia and bone marrow depression. JAMA 1990;264:1441-3.
Reiser S, Powell A, Yang CY, Canary JJ. Effect of copper intake on blood cholesterol and its lipoprotein distribution in men. Nutr Rep Int 1987;36:641-9.
Sandstead HH. Requirements and toxicity of essential trace elements, illustrated by zinc and copper. Am J Clin Nutr 1995;61(suppl):621S-24S [review].
Fischer PWF, Giroux A, Labbe MR. Effect of zinc supplementation on copper status in adult man. Am J Clin Nutr 1984;40:743-6.
Broun ER, Greist A, Tricot G, Hoffman R. Excessive zinc ingestion. A reversible cause of sideroblastic anemia and bone marrow depression. JAMA 1990;264:1441-3.
Nishiyama S, Irisa K, Matsubasa T, et al. Zinc status relates to hematological deficits in middle-aged women. J Am Coll Nutr 1998;17:291-5.
Muoz EC, Rosado JL, Lopez P, et al. Iron and zinc supplementation improves indicators of vitamin A status of Mexican preschoolers. Am J Clin Nutr 2000;71:789-94.
Dawson EB, Albers J, McGanity WJ. Serum zinc changes due to iron supplementation in teen-age pregnancy. Am J Clin Nutr 1990;50:848-52.
Crofton RW, Gvozdanovic D, Gvozdanovic S, et al. Inorganic zinc and the intestinal absorption of ferrous iron. Am J Clin Nutr 1989;50:141-4.
Argiratos V, Samman S. The effect of calcium carbonate and calcium citrate on the absorption of zinc in healthy female subjects. Eur J Clin Nutr 1994;48:198-204.
Spencer H, Norris C, Williams D. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. J Am Coll Nutr 1994;13:479-84.
Brumas V, Hacht B, Filella M, Berthon G. Can N-acetyl-L-cysteine affect zinc metabolisms when used as a paracetamol antidote? Agents Actions 1992; 36:278-88.
Barceloux DG. Zinc. J Toxicol Clin Toxicol 1999;37:279-92.
Bespalov VG, et al. [The effect of riboflavin, molybdenum, selenium and zinc on the development of induced tumors of the esophagus and forestomach in rats.] Voprosy Onkologii 1990;36:559-63.
Blot JW, et al. Nutrition intervention trials in Linxian, China: supplementation with specific vitamin/mineral combinations, cancer incidence, and disease-specific mortality in the general population. J Natl Cancer Inst 1993;85:1483.
Boik J. Cancer and natural medicine: a textbook of basic science and clinical research. Oregon: Medical Press 1995:147.
Diamond WJ, et al. An alternative medicine definitive guide to cancer. Tiburon: Future Medicine Publishing, Inc., 1997:793.
Doherty CP, et al. Zinc and rehabilitation from severe protein-energy malnutrition: higher-dose regimens are associated with increased mortality. Am J Clin Nutr 1998;68:742-8.
Kroll D. Megadoses and Toxicity. Alternative and Complementary Therapies 1995 Jan/Feb: 111.
Linder MC. Nutritional Biochemistry and Metabolism, 2nd Ed. New York: Elsevier Science Publishing Co. Inc., 1991:499,512.
Marti JE. Alternative health medicine encyclopedia: the authoritative guide to holistic and nontraditional health practices. Toronto: Gale Research Inc., 1995:74.
Mei W, et al. Study of immune function of cancer patients influenced by supplemental zinc or selenium-zinc combination. Biol Trace Elem Res 1991;28:9-11.
Munoz N, et al. Effect of riboflavin, retinol, and zinc on micronuclei of buccal mucosa and of esophagus: a randomized double-blind intervention study in China. J Natl Cancer Inst 1987;79:687-91.
Ontario Breast Cancer Information Exchange Project. Guide to unconventional cancer therapies. 1st ed. Toronto: Ontario Breast Cancer Information Exchange Project, 1994:148.
Rath FW, et al. The influence of zinc administration on the development of experimental lung metastases after an injection of tumour cells into the tail vein of rats. Exp Pathol 1991;41:215-17.
Rogers MA, et al. A case-control study of element levels and cancer of the upper aerodigestive tract. Cancer Epidemiol Biomarkers Prev 1993;2:305-312.
Somer E and Health Media of America. Essential guide to vitamins and minerals. USA: Harper Perennial, 1995:32-3,139,142.
Song MK, et al. Effect of different levels of dietary zinc on longevity of BALB/c mice inoculated with plasmacytoma MOPC 104E. J Natl Cancer Inst 1984;72:647-52.
Spencer JW, Jacobs JJ. Complementary/alternative medicine: an evidence based approach. Toronto: Mosby, 1999:136.
Strain J. Putative role of dietary trace element in coronary heart disease and cancer. Br J Biomed Sci 1994;51:241.
Boosalis, M.G., et al., Impaired Handling of Orally Administered Zinc in Pancreatic Insufficiency. Amer. Jour. Clin. Nut. 37 1983.
Eby, G.A., et al., Reduction in the Duration of Common Colds by Zinc Gluconate Lozenges in a Double-blind Study. Antimicrobial Agents and Chemotherapy 25 1984.
Fahim, M., et al., Zinc Treatment for the Reduction of Hyperplasia of the Prostate, Federation Proceedings 35 1976.
Michaelson, G., et al., Serum Zinc and Retinol Binding-protein in Acne. Brit. Jour. of Dermatology. 96 1977.
Pandley, S.P., et al., Zinc in Rheumatoid Arthritis. Ind. Jour. of Med. Research 81 1985
Ripa, S., Zinc and Immune Function. Minerva-Med. 86 1995.
Russel, R.M., et al., Zinc and the Special Senses. Annals of internal Medicine 99 1983.
Sandstead, H.H., et al., Zinc Nutriture in the Elderly in Relation to Taste Acuity, Immune Response, and Wound Healing. Amer. Jour. Clin. Nut. 36 1982
Simkin, P.A. Treatment of Rheumatoid Arthritis With Oral Zinc Sulphate. Agents and Actions (Supplement) 1981.
Whitehouse, M.W., et al., Zinc Monoglycerolate: A Slow-release Source of Zinc With Anti-arthritis Activity in Rats. Agents and Actions 31 1990.