Zinc

Introduction

Zinc is necessary for the functioning of over 300 different enzymes and, as such, it plays a vital role in an enormous number of biological processes. Much attention has been placed on this mineral for its role in the immune system. In humans, the highest concentrations of zinc are found in the liver, pancreas, kidneys, bone, and muscles.

The best dietary sources of zinc are lean meats, liver, eggs, and seafood (especially oysters). Whole grain breads and cereals are also good sources of zinc.

Dosage Info

Dosage Range

2-50mg elemental zinc daily. Doses of zinc sulfate as high as 220mg, three times a day have been evaluated for the treatment of sickle cell disease. (1)

Most Common Dosage

25mg daily.

23% elemental zinc contained in zinc sulfate
14.3% elemental zinc contained in zinc gluconate

Dosage Forms

Tablets, capsules, liquid, and lozenges.

Interactions and Depletions

Interactions

• H-2 receptor antagonists
• Tetracyclines
• copper
• iron

Depletions

• ACE inhibitors
• clofibrate
• Corticosteroid medications
• ethambutol
• Loop diuretics
• Oral contraceptives
• penicillamine
• Thiazide diuretics
• valproic acid
• zidovudine (AZT)

Reported Uses

Zinc helps regulate a wide variety of immune system functions and it may stimulate anti-viral activity. (2) , (3) , (4) Because of these benefits, it has been studied for use as a treatment for the common cold. (5) , (6) It is also a component of one of the body’s important antioxidants and may facilitate wound healing, especially burns, surgical, and scars. (7)

Zinc also plays an important role in the reproductive system where it is necessary for the development of sperm, for ovulation and for fertilization. Zinc deficiency during pregnancy may have an effect on fetal and maternal health. It is also involved in sensory perceptions like taste, smell and vision. Zinc may also be involved with controlling blood sugar levels and has been studied for use in the support of the symptoms of diabetes. (8) , (9)

Zinc has been studied for use in a wide range of other disorders. Zinc supplementation may support healthy skin and inhibit acne, eczema and psoriasis. (10) , (11) , (12) Also, zinc may have anti-inflammatory properties that could benefit arthritis sufferers. (13) , (14) , (15)

Other potential benefits, zinc may support prostate health and prevent the progression of benign prostate enlargement. Zinc has been used with positive results to treat stomach ulcers and inflammatory bowel disease. (16) , (17) , (18) Zinc supplementation may support healthy vision and prevent macular degeneration. (19) , (20) And finally, because zinc enhances vitamin D activity, it may play a supportive role in fighting osteoporosis. (21) , (22) , (23)

Toxicities & Precautions

Introduction

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General

Doses of 45mg per day are safe, but regular intake greater than 150mg per day could be a problem. Zinc toxicity can cause diarrhea, dizziness, drowsiness, vomiting, loss of muscle coordination and lethargy. Tell your doctor if any of these effects occur.

Side Effects

Side effects are possible with any dietary supplement. The zinc gluconate lozenges may cause a mild stomach upset and a metallic taste in the mouth while using them. (24) Other forms of zinc supplementation have been associated with nausea and vomiting when taken in larger doses. Tell your doctor if these side effects become severe or do not go away.

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development in well nourished pregnant women eating a well-balanced diet or to infants who are breast-fed. Proper nutrition is essential during pregnancy for the healthy development of the fetus. Numerous vitamins and minerals are a vital part of proper nutrition. If you are pregnant, think you might be pregnant, trying to get pregnant, or breast-feeding an infant, talk to your healthcare professional about supplementing your diet with appropriate vitamins and minerals.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Vitamins and minerals are an essential part of proper growth and development. Talk to your healthcare professional about the appropriate use of vitamins and minerals in children. Do not use any vitamin or mineral in children under 2 years of age unless first discussed with your healthcare professional.

References

1. View Abstract: Gupta VL, Chaubey BS. Efficacy of zinc therapy in prevention of crisis in sickle cell anemia: a double blind, randomized controlled clinical trial. J Assoc Physicians India. Jul 1995;43(7):467-469.
2. View Abstract: Fraker PJ, et al. Interrelationships Between Zinc and Immune Function. Fed Proc. Apr1986;45(5):1474-79.
3. View Abstract: Taylor CG, et al. Dietary zinc deficiency and expression of T lymphocyte signal transduction proteins. Can J Physiol Pharmacol. Oct2000;78(10):823-8.
4. View Abstract: Paisey SJ, Sadler PJ. Anti-viral cyclam macrocycles : rapid zinc uptake at physiological pH. Chem Commun (Camb). Feb2004;(3):306-7. Epub 2004 Jan 06.
5. View Abstract: Mossad SB, et al. Zinc Gluconate Lozenges for Treating the Common Cold. A Randomized, Double-blind, Placebo-controlled Study. Ann Intern Med. Jul1996;125(2):81-88.
6. View Abstract: Mossad SB. Effect of zincum gluconicum nasal gel on the duration and symptom severity of the common cold in otherwise healthy adults. QJM. Jan2003;96(1):35-43.
7. View Abstract: Okada A, et al. Zinc in Clinical Surgery–A Research Review. Jpn J Surg. Nov1990;20(6):635-44.
8. View Abstract: Nakamura T, et al. Kinetics of Zinc Status in Children with IDDM. Diabetes Care. Jul1991;14(7):553-57.
9. Pidduck HG, et al. Plasma Zinc and Copper in Diabetes Mellitus. Diabetes. Apr1970;19(4):234-39.
10. View Abstract: Verma KC, et al. Oral Zinc Sulphate Therapy in Acne Vulgaris: A Double-blind Trial. Acta Derm Venereol. 1980;60(4):337-40.
11. View Abstract: David TJ, et al. Low Serum Zinc in Children with Atopic Eczema. Br J Dermatol. Nov1984;111(5):597-601.
12. View Abstract: Michaelsson G, et al. Patients with Dermatitis Herpetiformis, Acne, Psoriasis and Darier’s Disease have Low Epidermal Zinc Concentrations. Acta Derm Venereol. 1990;70(4):304-08.
13. View Abstract: Simkin PA. Oral Zinc Sulphate in Rheumatoid Arthritis. Lancet. Sep1976;2(7985):539-42.
14. View Abstract: Peretz A, et al. Effects of zinc supplementation on the phagocytic functions of polymorphonuclears in patients with inflammatory rheumatic diseases. J Trace Elem Electrolytes Health Dis. Dec1994;8(3-4):189-94.
15. View Abstract: Cerhan JR, Saag KG, Merlino LA, Mikuls TR, Criswell LA. Antioxidant micronutrients and risk of rheumatoid arthritis in a cohort of older women. Am J Epidemiol. Feb2003;157(4):345-54.
16. View Abstract: Frommer DJ. The Healing of Gastric Ulcers by Zinc Sulphate. Med J Aust. Nov1975;2(21):793-96.
17. Hendricks KM, Walker WA. Zinc Deficiency in Inflammatory Bowel Disease. Nutr Rev. 1988;46(12):401-08.
18. View Abstract: Sturniolo GC, et al. Zinc supplementation tightens “leaky gut” in Crohn’s disease. Inflamm Bowel Dis. May2001;7(2):94-8.
19. View Abstract: Newsome DA, et al. Oral Zinc in Macular Degeneration. Arch Ophthalmol. Feb1988;106(2):192-98.
20. View Abstract: Christian P, et al. Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women. Am J Clin Nutr. Jun2001;73(6):1045-51.
21. View Abstract: Angus RM, et al. Dietary Intake and Bone Mineral Density. Bone Miner. Jul1988;4(3):265-77.
22. View Abstract: Igarashi A, et al. Increase in bone protein components with healing rat fractures: enhancement by zinc treatment. Int J Mol Med. Dec1999;4(6):615-20.
23. View Abstract: Saltman PD, et al. The role of trace minerals in osteoporosis. J Am Coll Nutr. Aug1993;12(4):384-9.
24. View Abstract: Macknin ML, Piedmonte M, Calendine C, Janosky J, Wald E. Zinc gluconate lozenges for treating the common cold in children: a randomized controlled trial. JAMA. Jun1998;279(24):1962-1967.