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Supplements

zinc

What Is It?
Health Benefits
Forms
Recommended Intake
If You Get Too Little
If You Get Too Much
General Dosage Information
Guidelines for Use
General Interaction
Cautions
References
Evidence Based Rating System


What Is It?

Zinc is an essential trace mineral. Every cell in the body needs this nutrient and hundreds of body processes rely on it, from the immune system and the enzymes that produce DNA to the senses of taste and smell. Although the body does not produce zinc on its own, this mineral is readily available in drinking water and certain foods. Even so, a surprising number of adults fail to get enough of this mineral through their diet. Better food choices and a good multivitamin and mineral supplement can help compensate for such mild deficiencies.

There's now evidence that supplements may also be useful in providing the extra zinc needed to fight cold and flu symptoms. In addition, zinc has shown promise for speeding the healing of canker sores and sore throat, promoting recovery from skin injuries, reducing tinnitus (ringing in the ears), and controlling acne and eye problems.

Health Benefits

Zinc is believed to promote a strong immune system by, among other things, revitalizing the thymus gland and its production of white blood cells. In addition, autoimmune diseases (chronic ailments linked to the improper functioning of the immune system, such as lupus, rheumatoid arthritis, or fibromyalgia) may also benefit from zinc supplementation.

Interestingly, the presence of too little zinc has been linked to a decreased immune response in older people. Again, supplemental zinc may be a viable remedy. In a study of 118 relatively healthy but elderly nursing home residents in Italy, researchers found that those given 25 mg of zinc daily for three months developed stronger immune systems. (1)

By boosting the immune system, zinc may also protect against fungal infections and various infectious disorders, such as conjunctivitis and pneumonia. It also has anti-inflammatory properties.

Specifically, zinc may help to:

  • Fight colds and flu.

    When taken promptly at the first signs of illness, zinc lozenges can minimize the duration and severity of cold and flu symptoms. (2-6) Research indicates that the zinc may actually destroy the cold virus, cutting the duration of an infection nearly in half. In one study, common colds disappeared about three days earlier in participants who sucked on zinc lozenges every couple of hours instead of on a Placebo lozenge. (2)

    Only zinc in the form of zinc gluconate, ascorbate, or glycinate will fight a cold, however, so pick your product carefully. Avoid lozenges containing sorbitol, mannitol, or citric acid, as these chemicals, when combined with saliva, make zinc ineffective. And zinc taken prophylactically does not seem to prevent colds. (7, 8).

  • Accelerate healing of canker sores and sore throat. Zinc lozenges appear not only to boost your resistance to canker sores but also make them heal more quickly should they appear. The lozenges may even stave off a sore throat that's threatening to develop as a result of a cold.

     

  • Promote healing of skin wounds, eczema, rosacea, burns, and other irritations.

    Zinc repairs the skin's top layer in part by helping to process the essential fatty acids that encourage healing. Adding zinc supplements to your diet may therefore lead to more efficient recovery from acne, burns, psoriasis, rosacea, hemorrhoids and eczema, especially if the affected area is not healing well. The body also requires extra nutrients such as zinc to help repair burned skin and reinforce the immune response. (9, 10)

     

  • Control acne. In some studies, zinc has been linked to skin health because it enhances the immune system, reduces Inflammation, and promotes healthy Hormone levels. Acne may improve as a result. In one study, zinc when taken in conjunction with topical prescription Antibiotic solutions, such as erythromycin and clindamycin, considerably increased the capacity of these medications to clear up the acne. (11-14) Because long-term use of zinc inhibits copper absorption, it should be taken along with that mineral. One study reported that participants taking 30 mg of zinc daily had a clearer complexion after two months than participants taking a placebo, at least according to the evaluating physicians. (15) In a separate study, zinc performed as well as the standard acne antibiotic, tetracycline. (16) Not all studies have found zinc to be beneficial for acne, however.

  • Reduce tinnitus. High concentrations of zinc are found in the inner ear. A Japanese study tested the theory that insufficient levels of zinc may therefore contribute to tinnitus. Researchers found that tinnitus sufferers with low zinc levels in their blood experienced an improvement in their symptoms when, after two weeks of zinc supplementation, their zinc levels rose significantly. (17).

     

  • Treat eye problems. Zinc appears to boost the effectiveness of Vitamin A, a nutrient well known for its role in keeping the eyes healthy. In addition, zinc plays a critical role in the functioning of the retina and the light-sensitive area known as the macula found within it. Supplements have been shown to slow vision loss in individuals with macular degeneration, a common cause of blindness in individuals over age 50. (18) Symptoms of the inflammatory eye condition known as conjunctivitis, or pinkeye, may lessen with zinc as well. In a French study of people with symptoms of conjunctivitis from seasonal allergies, zinc combined with antihistamines led to considerable improvement in 78% of the study participants. (19) In the case of infection in the eye, keep in mind that even mild cases that fail to clear rapidly should be seen by a doctor.

  • Control diabetes. By improving levels of insulin (the hormone so important to regulating the body's energy supply) zinc supplements may help people with type 1 or 2 diabetes manage their disease more effectively. In addition, some people with diabetes have wounds that fail to heal well; this problem relates in part to the presence of high blood sugar levels and zinc may help to control problems. (20, 21)

     

  • Minimize digestive complaints. Zinc's ability to foster healing may make it valuable in treating ulcers and other digestive tract problems. (22) Interestingly, individuals with inflammatory bowel disease often suffer from a zinc deficiency. Supplements can help to normalize zinc levels.

     

  • Protect against osteoporosis. By promoting mineral absorption and keeping bones healthy, zinc may help to prevent this progressive bone disorder and its associated disabling complications, such as fractures. Zinc is often taken with copper, which plays a critical role in keeping Collagen--a Protein that strengthens the bones and connective tissue--in good shape. At least six months of treatment with zinc/copper combinations are needed before bone-strengthening effects occur. (23-25).

     

  • Treat hormone-related infertility problems. Zinc's effect on sex hormones may make it valuable in treating infertility in both women and men. Zinc plays a positive role in female fertility by promoting proper cell division, a process critical to the earliest stages of conception and fetal development. Similarly, in male reproduction zinc may well be necessary for adequate testosterone levels and sperm counts. (26).

     

  • Reduce the size of an enlarged prostate. Zinc ranks among the key nutrients for the health of the prostate gland in men. Some evidence indicates that it may not only reduce an enlarged prostate but actually relieve symptoms of benign prostatic hyperplasia (BPH), a common but bothersome condition that can result in problems such as difficulty urinating and weak urine flow. (27) Zinc supplements are most appropriate for prostate problems (BPH, specifically) categorized as mild to moderate; check with your doctor to see if your case qualifies as such. In fact, a doctor should check your condition regularly every six months to track your progress.

  • Nourish hair. Zinc, along with other vitamins and minerals, promotes hair growth. It may even help slow the loss of hair and counter brittleness, particularly if the problems are due to an underactive thyroid gland. Extra benefits are derived from combining zinc with copper, as this mineral is an essential ingredient in melanin, a natural pigment in hair.

    Note: Zinc has been found to be useful for a number of other disorders. For information on these additional ailments, see our Dosage Recommendations Chart for Zinc.

  • Forms

    • tablet
    • lozenge
    • liquid
    • capsule

    Recommended Intake

    While the RDA for zinc is 15 mg for adult men and 12 mg for adult women, higher doses are typically used for specific complaints.

    If You Get Too Little

    Severe zinc deficiency is rare in developed countries. But even a mild deficiency in this mineral can result in a host of ills, from increased risk for colds and flu to impaired wound healing and a diminished sense of smell. Skin ailments such as eczema, acne, and psoriasis may develop. Low sperm counts may occur. Blood sugar (glucose) tolerance may be compromised, with an associated increased risk for diabetes. In addition, over time, impaired immunity may develop.

    If You Get Too Much

    Zinc in amounts greater than 200 mg a day can cause nausea, vomiting, and diarrhea. Taking even 100 mg a day in supplement form over long periods can result in problems, including lowered levels of HDL ("good") cholesterol and diminished immune-system function.

    An association between excessive zinc and Alzheimer's disease has been made but requires further investigation.

    General Dosage Information

    Special tips: High-quality multivitamin and mineral supplements typically contain the RDA for zinc.

    --Zinc pills or liquids in the following forms are well absorbed and generally gentle on the stomach: zinc picolinate, zinc acetate, zinc citrate, zinc monomethionine, and zinc glycerate.

  • When treating the majority of ailments mentioned: Take 30 mg once a day.

     

  • For colds or flu: Suck on one zinc gluconate lozenge every two hours for as long as cold or flu symptoms persist.

     

  • For sore throat: Suck on one zinc gluconate lozenge every two hours as needed.

     

  • For canker sores: Suck on one lozenge every two hours for three or four days.

     

  • For eye infections: Take 30 mg a day for one month.

    Be sure to check out our Dosage Recommendations Chart for Zinc, which lists therapeutic dosages for specific ailments at a glance.

  • Guidelines for Use

  • Zinc lozenges taken for a sore throat can safely be combined with over-the-counter or prescription medications.

     

  • When treating osteoporosis, zinc may safely be added to a regimen of prescription drugs or estrogen therapy. Many "bone-building" supplement combinations contain zinc along with calcium, magnesium, vitamin D, and other nutrients vital to bone health.

     

  • When treating rosacea or psoriasis, it may take about a month of zinc supplementation before you see any improvements.

     

  • When treating acne, zinc may safely be combined with conventional acne medications, but may interact with certain antibiotics. Caution is warranted. It may take three weeks or more to see results.

     

  • Zinc supplements can safely be combined with many prescription drugs for diabetes, but consult your doctor to ensure that your need for insulin doesn't change.

     

  • If you are a coffee drinker, be sure to take zinc supplements at least one hour before or two hours after drinking the coffee; the absorption of zinc is reduced by 50% when taken with coffee.

     

  • General Interaction

  • Absorption of copper may be compromised by long-term (a month or more) ingestion of zinc. So, as a precaution, supplement every 30 mg of zinc with 2 mg of copper.

     

  • If you also take iron supplements, avoid absorption problems by taking the zinc two hours after the iron.

     

  • Because zinc may decrease the absorption of the antibiotics tetracyline, doxycycline, and minocycline, making them less effective, take zinc at least two hours after the antibiotic.

    Note: For information on interactions with specific generic drugs, see our WholeHealthMD Drug/Nutrient Interactions Chart.

  • Cautions

  • Total daily intake of zinc (from supplements, foods, and other sources combined) should not surpass 150 mg a day.
  • References

    1. Fortex C, Forastiere F, Agabiti N, et al. The effect of zinc and vitamin A supplementation on immune response in an older population. J Am Geriatr Soc. 1998;46:19-26.

    2. Mossad SB, Macknin ML, Medendorp SV, Mason P. Zinc gluconate lozenges for treating the common cold. A randomized,  double-blind, placebo-controlled study. Ann Intern Med. 1996;125:81-8.

    3. Godfrey JC, Conant Sloane B, Smith DS, et al. Zinc gluconate and the common cold: a controlled clinical study. J Int Med Res. 1992;20:234-6.

    4. Al-Nakib W, Higgins PG, Barrow I, et al. Prophylaxis and treatment of rhinovirus colds with zinc gluconate lozenges. J Antimicrob Chemother. 1987;20:893-901.

    5. Prasad AS, Fitzgerald JT, Bao B, et al. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 2000;133:245-52.

    6. Petrus EJ, Lawson KA, Bucci LR, Blum K. Randomized, double-masked, placebo-controlled clinical study of the effectiveness of zinc acetate lozenges on common cold symptoms in allergy-tested subjects. Curr Ther Res. 1998;59:595-607.

    7. Takkouche B, Regueira-Mendez C, Garcia-Closas R, et al. Intake of vitamin C and zinc and risk of common cold: a cohort study. Epidemiology. 2002;13:38-44.

    8. Turner RB, Cetnarowski WE. Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds. Clin Infect Dis. 2000;31:1202-8.

    9. Michaelsson G, Ljunghall K. Patients with dermatitis herpetiformis, acne, psoriasis and Darier’s disease have low epidermal zinc concentrations. Acta Derm Venereol. 1990;70:304-8.

    10. Berger MM, Spertini F, Shenkin A, et al. Trace element supplementation modulates pulmonary infection rates after major burns: a double-blind, placebo-controlled trial. Am J Clin Nutr. 1998;68:365-71.

    11. Pierard-Franchimont C, Goffin V, Visser JN, et al. A double-blinjd controlled evaluation of the sebosuppressive activity of topical erythromycin-zinc comples. Eur J Clin Pharmacol. 1995;49:57-60.

    12. Feucht CL, Allen BS, Chalker DK, et al. Topical erythromycin with zinc in acne. A double-blind controlled study. J Am Acad Dermatol. 1980;3:483-91.

    13. Schachner L, Eaglstein W, Kittles C, Mertz P. Topical erythromycin and zinc therapy for acne. J Am Acad Dermatol. 1990;22:253-60.

    14. Habbema L, Koopmans B, Menke HE, et al. A 4% erythromycin and zinc combination (Zineryt) versus 2%erythromycin (Eryderm) in acne vulgaris: a randomized, double-blind comparative study. Br J Dermatol. 1989;121:497-502.

    15. Dreno B, Amblard P, Agache P, et al. Low doses of zinc gluconate for inflammatory acne. Acta Derm Venereol. 1989;69:541-3.

    16. Mchaelsson G, Juhlin L, Ljunghall K. A double-blind study of the effect of zinc and oxytetracycline in acne vulgaris. Br J Dermatol. 1977;97:561-6.

    17. Ochi K, Ohashi T, Kinoshita H, et al. [The serum zinc level in patients with tinnitus and the effect of zinc treatment]. Nippon Jibiinkoka Gakkai Kaiho. 1997 Sep;100(9):915-9. PMID 9339660.

    18. Grahn BH, Paterson PG, Gottschall-Pass KT, Zhang Z. Zinc and the eye. J Am Coll Nutr. 2001;20:106-18.

    19. Favennec F, Catros A. [Zinc and seasonal conjunctivitis.] Allerg Immunol (Paris). 1993 Mar;25(3):119-22.

    20. Lopez-Ridaura R, Willett WC, Rimm EB, et al. Magnesium intake and risk of type 2 diabetes in men and women. Diabetes Care. 2004;27(1):134-140.

    21. Fung TT, Manson JE, Solomon CG, et al. The association between magnesium intake and fasting insulin concentration in healthy middle-aged women. Journal of the American College of Nutrition. 2003;22(6):533-538.

    22. Garcia-Plaza A, Arenas JI, Belda O, Diago A, et al. [A multicenter, clinical trial. Zinc acexamate vs famotidine in the treatment of acute duodenal ulcer. Study group of zinc acexamate]. [Article in Spanish]. Rev Esp Enferm Dig. 1996;88:757-62.

    23. Atik OS. Zinc and senile osteoporosis. J Am Geriatr Soc. 1983;31:790-1.

    24. Hyun TH, Barrett-Connor E, Milne DB. Zinc intakes and plasma concentrations in men with osteoporosis: the Rancho Bernardo Study. Am J Clin Nutr. 2004;80:715-21.

    25. Strause L, Saltman P, Smith KT, et al. Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals. J Nutr. 1994;124:1060-4.

    26. Barceloux DG. Zinc. J Toxicol Clin Toxicol. 1999;37:279-92.

    27. Lagiou P, Wuu J, Trichopoulou A, et al. Diet and benign prostatic hyperplasia: a study in Greece. Urology. 1999 Aug;54(2):284-90.

    28. Prasad AS. Clinical, biochemical and nutritional spectrum of zinc deficiency in human subjects: an update. Nutr Rev. 1983;41:197-208.

    29. Krause, M, Mahan L. Food, Nutrition and Diet Therapy, ed 7. Philadelphia: WB Saunders, 1984.
    30. Harrap GJ, Saxton CA, Best JS. Inhibition of plaque growth by zinc salts. J Periodontal Res. 1983;18:634-42.
    31. Tamura M, Ochiai K. Zinc and copper play a role in coaggregation inhibiting action of Porphyromonas gingivalis. Oral Microbiol Immunol. 2009 Feb;24(1):56-63.

    32. Strause L, Saltman P, Smith KT, et al. Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals. J Nutr. 1994;124:1060-4

    33. Agren MS. Studies on zinc in wound healing. Acta Derm Venereol Suppl (Stockh) 1990;154:1-36.

    34. Yang XD, Wang JP, Kang JB, et al. [Comparison of the efficacy and safety of compound carraghenates cream and compound carraghenates suppository in the treatment of mixed hemorrhoids]. Zhonghua Wei Chang Wai Ke Za Zhi. 2005 May;8(3):220-2.

    35. Zhong YS, Yao LQ.Usage of titanoreine after procedure for prolapse and hemorrhoids. Zhonghua Wei Chang Wai Ke Za Zhi. 2005 Jul;8(4):319-21.


    Evidence Based Rating Scale   

    The Evidence Based Rating Scale is a tool that helps consumers translate the findings of medical research studies with what our clinical advisors have found to be efficacious in their personal practice. This tool is meant to simplify which supplements and therapies demonstrate promise in the treatment of certain conditions. This scale does not take into account any possible interactions with any medication/ condition/ or therapy which you may be currently undertaking. It is therefore advisable to ask your doctor before starting any new treatment regimen.

    Condition

    Rating

    Explanation


    Date Published: 04/19/2005
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