‌‌‌‌What Is Zinc?

Zinc is a critical trace mineral that is found in every cell in the human body. It primarily functions as a component in over 200 enzymes. The enzymes use zinc to build many important compounds and structural components necessary for human bodily function. In fact, zinc functions in more enzymatic reactions than any other mineral. 

Most enzymes are composed of a protein along with an essential mineral and possibly a vitamin. If an enzyme is lacking the essential mineral or vitamin, it cannot function properly. If zinc levels are low, it disrupts virtually every system of the body due to its central role in so many enzymes. In addition to its role in enzymes, zinc is required for the proper action of many body hormones including insulin, growth hormone, and sex hormones like testosterone and estrogen. 

Adequate zinc levels are absolutely essential to good health. The beneficial effects of zinc are extensive. It is especially important to proper immune function, wound healing, brain, and sensory functions, sexual function, and skin health.

Although severe zinc deficiency is very rare in developed countries, it is believed that many individuals around the world, including the United States, have a marginal zinc deficiency, especially in the infant and elderly populations. Zinc deficiency can be caused by decreased intake and/or increased utilization. Dietary surveys indicate that average zinc intakes range from only 47% to 67% of the recommended dietary allowance (RDA). Determining marginal zinc deficiency is complex,1  but may be reflected by an increased susceptibility to depression, infection, a decreased sense of taste or smell, and a number of minor skin disorders including acne and poor wound healing. Some other physical findings that often correlate with low zinc status include decreased ability to see at night or with poor lighting, impaired growth and development in children, testicular atrophy, mouth ulcers, a white coating on the tongue, and marked halitosis (bad breath).

‌‌‌‌What Health Conditions Are Predisposed To Zinc Deficiency?

Decreased intake:

  • Acute infections/inflammation
  • Alcoholic cirrhosis
  • Alcoholism
  • Anorexia nervosa
  • Burns
  • Post-trauma
  • Protein deficiency
  • Vegetarian diet
  • Starvation

Decreased Absorption:

  • Alcoholism
  • Celiac disease
  • Chronic blood loss
  • Diabetes mellitus
  • Diarrhea
  • High fiber diet
  • High dietary calcium:zinc ratio
  • High dietary iron:zinc ratio
  • Inflammatory bowel disease
  • Intestinal Resection
  • Liver disease
  • Pancreatic insufficiency

Increased Requirement:

  • Old age
  • Pregnancy and lactation
  • Oral contraceptive use
  • Growth spurts and puberty

‌‌‌‌What Health Conditions Benefit From Zinc Supplementation?

Zinc plays a huge role in overall health. Its importance cannot be overstated. It is also very important in addressing many specific health challenges, especially when zinc levels may be low. 

The scientific support for zinc supplementation is extremely well supported in the medical literature as there have been over 1,000 double-blind, placebo-controlled studies where zinc supplementation was shown to be of benefit in many different types of challenges and in restoring health. Here are some health challenges that have the most support and apparent need for zinc supplementation:

  • Acne and Other Skin Issues
  • Brain Health, Sleep, and Mood
  • Immune System Enhancement and the Common Cold
  • Diabetes
  • Macular Degeneration
  • Male Sexual Function
  • Pregnancy
  • Premenstrual Syndrome
  • Rheumatoid Arthritis and Inflammation

1. Acne And Other Skin Issues

Zinc is a very important supplement consideration to support the structure and health of the skin, hair, and nails. Zinc supplementation has been shown to offer considerable benefits in improving these issues. It strengthens nails, is critical for hair growth and texture, and is required for the skin to retain the proper hydration (water) and oil content.

Zinc supplementation is particularly helpful when the skin is stressed by acne as it exerts beneficial effects on both sebum production and hormonal metabolism. Low zinc levels are often found in adolescents and may be a predisposing risk factor for acne. Several double-blind studies showed zinc supplementation to produce similar results to tetracycline (an antibiotic) in superficial acne and superior results in deeper acne.2,3 Although some people in these studies showed dramatic improvement immediately, the majority usually required 12 weeks of supplementation before good results were achieved. So, be patient.

Zinc has also shown benefits in promoting wound healing. This effect is very important in people with diabetes as they are at risk for poor wound healing and subsequent infections. The same is true for people prone to boils and folliculitis. 

The importance of zinc to wound healing was clearly demonstrated in a double-blind study in 60 patients with grade 3 diabetic foot ulcers.4 The patients given 50 mg zinc (sulfate) per day showed significant improvements after 12 weeks in ulcer healing as well as improved blood sugar control, total antioxidant capacity in the blood, blood glutathione levels, and decreased markers of inflammation. All of these improvements were the apparent result of restoring adequate zinc levels to the body.

2. Brain Health, Sleep Quality, And Mood

Zinc deficiency produces profound changes in brain chemistry resulting in both depression and impaired mental function in humans. Zinc deficiency is one of the most common nutrient deficiencies in both children and the elderly and has been suggested to be a major factor in the development of both poor mental function and memory as well as low mood in these age groups. Not surprisingly, clinical studies with zinc supplementation have shown some beneficial effects in improving both mood and some aspects of mental function in both children and the elderly.5

Zinc deficiency is also quite common in some regions of the world, e.g., the Middle East. In one study in Iran, dietary intake of zinc (was significantly lower among subjects with mild to severe depression symptoms than those with no or minimal depressive symptoms.6

Another group where zinc deficiency may be an underlying factor in low mood and brain function are people who are overweight or dealing with poor blood sugar control. In one study, 50 overweight subjects were randomly assigned into two groups and received either 30 mg zinc (monomethionine) or placebo daily for 12 weeks. Zinc supplementation produced improved mood scores, as well as a biological marker of new brain cell production, compared to the placebo group.7

Some of the benefits of zinc in improving mood may be a result of improved sleep quality. In a double-blind clinical trial, the 54 intensive care unit (ICU) nurses who took 50 mg of zinc (sulfate) once every three days for one month experienced significant improvements in sleep quality. These improvements corresponded to the increase in zinc levels in the blood.8 

3. The Common Cold

Zinc is involved in virtually every aspect of immune function. In fact, zinc has been referred to zinc as the “gatekeeper” of immune function.9 Zinc supplementation has shown to be able to reverse low immune function, especially the lowered immunity characteristic of aging.10,11 This effect may be due to restoring blood levels of thymulin (a hormone produced by the thymus gland). Typically, as people age the level of thymulin and other immune-enhancing thymus hormones are reduced. The reduction of these hormones leads to impaired immune function and increased risk of infection. By restoring the levels of thymulin, zinc supplementation can significantly improve immune function. Another effect of zinc supplementation noted in studies in the elderly is that it improved overall nutritional status. This effect signifies the importance of zinc in the proper absorption and utilization of other nutrients.

Zinc also possesses some direct antiviral activity, including antiviral activity against several viruses that can cause the common cold.12 The use of zinc supplements, particularly as a lozenge, appears to be of much value during a cold. However, while some studies showed great results, others did not.13 This inconsistency is thought to be due to an ineffective lozenge formulation in the negative studies. In order for zinc to be effective, it must be free (ionized) in saliva. Citric acid appears to reduce the effectiveness. Therefore, be sure to use zinc lozenges free of citric acid. It is also important when using zinc-containing lozenges for the relief of a sore throat or common cold, do not eat or drink citrus fruits or juices 1/2 before and after dissolving the lozenge, as the citric acid will negate the effect of zinc.

4. Diabetes and Blood Sugar Control

Zinc is involved in virtually all aspects of insulin metabolism: synthesis, secretion, and utilization. Unfortunately, zinc deficiency is common in patients with diabetes.14 And without sufficient zinc, insulin simply does not work properly. Zinc supplementation, as well as virtually all other water-soluble vitamins and minerals, is essential as people with Diabetes typically excrete too much zinc and other water-soluble nutrients in the urine. Several studies have shown zinc supplementation to improve insulin sensitivity in people with prediabetes or diabetes.15 As discussed above, zinc is also important for proper wound healing and immune function that is critical in diabetes.

4. Male Sexual Function

Zinc is critical for male sexual function. It is involved in hormone metabolism, sperm formation, and sperm motility. Zinc deficiency is characterized by, among many other things, decreased testosterone levels and sperm counts. Zinc levels are typically much lower in infertile men with low sperm counts indicating that a low zinc status may be the contributing factor to infertility. Several double-blind studies have shown that zinc supplementation can improve sperm counts and motility. It is especially effective in boosting sperm counts in men with low testosterone levels.16

6. Macular Degeneration

Zinc has been shown to be beneficial in reducing vision loss in the treatment of age-related macular degeneration (ARMD). Zinc plays an essential role in the metabolism of the retina, and the elderly are at high risk for zinc deficiency.17 In addition to the studies with a combination of nutrients, zinc alone has been shown to improve ARMD. In fact, it was the impressive results with zinc supplementation that led to the famous Age-Related Eye Disease Studies conducted by the National Institutes of Health (NIH).

7. Pregnancy

Low zinc levels are linked to premature births, low birth weight, growth retardation, and pre-eclampsia - a serious condition of pregnancy-associated with elevations in blood pressure, fluid retention, and loss of protein in the urine. Some studies of zinc supplementation in pregnancy have shown that the zinc-supplemented group demonstrated greater body weight and head circumference compared to the placebo group and fewer complications of pregnancy.18

8. Premenstrual Syndrome

Premenstrual syndrome is a common occurrence for many women during their reproductive years. Nutritional factors appear to be an underlying factor. For many women, zinc may be the key nutrient to bring things into balance as several clinical studies have shown positive benefits. For example, in a double-blind trial in 60 young university women, those given 30 mg/day of zinc experienced significant improvements in quality of life scores, especially as it related to both physical (energy levels, sleep quality, reduced breast tenderness, etc.) and psychological aspects (e.g., mood scores) in quality of life assessments in young women with premenstrual syndrome.19,20

9. Rheumatoid Arthritis

Zinc has antioxidant effects as well as functions in the antioxidant enzyme superoxide dismutase (copper-zinc SOD). Zinc levels are typically reduced in patients with rheumatoid arthritis and other inflammatory conditions. Several studies have used zinc supplementation to restore adequate zinc levels in rheumatoid arthritis, with some of the studies demonstrating corresponding improvements in zinc-related functions.21 Most of the studies utilized zinc in the form of zinc sulfate. Better results may have been produced by using a more absorbable form of zinc.

‌‌‌‌What Is The Usual Dosage Of Zinc?

In adults, the dosage range for zinc supplementation for general health support and during pregnancy or lactation is 15 to 20 mg. For children, the dosage range is 5 to 10 mg. When zinc supplementation is being used to address specific health concerns, the dosage range for men is 30 to 45 mg; for women 20 to 30 mg. There is no need to go beyond this dosage level.

During the common cold, use lozenges that supply 15 to 25 mg of elemental zinc and dissolve them in the mouth every two waking hours after an initial double dose. Continue for up to seven days. Because high doses of zinc can impair immune function, avoid a daily intake of greater than 150 mg of zinc for longer than one week.

‌‌‌‌What Forms Of Zinc Are Available?

There are many forms of zinc to choose from. While many clinical studies have utilized zinc sulfate, this form is not as well absorbed as other forms such as zinc picolinate, acetate, citrate, bisglycinate, oxide, or monomethionine are all excellent forms of zinc. There is data to support each of these forms as being very well-absorbed and able to produce benefits. Most zinc lozenges are made with zinc gluconate, which appears to be an effective form for this application.

‌‌‌‌What Are The Possible Side Effects of Zinc Supplementation?

If taken on an empty stomach (particularly if taking zinc sulfate), zinc supplementation can result in gastrointestinal upset and nausea. Prolonged intake at levels greater than 150 mg per day may lead to anemia, reduced HDL-cholesterol levels, and decreased immune function.

‌‌‌‌Does Zinc Have Any Drug Interactions?

Zinc may decrease the absorption of tetracycline and ciprofloxacin. Take any zinc supplement at least 2 hours before or after taking these antibiotics.

Use of the following drugs increases the loss of zinc from the body or interferes with absorption: aspirin; AZT (azidothymidine); captopril; enalapril; estrogens (oral contraceptives and Premarin®); penicillamine; and the thiazide class of diuretics. Supplementation may be required to maintain zinc status in people taking these drugs.


  1. King JC. Zinc: an essential but elusive nutrient. Am J Clin Nutr. 2011 Aug;94(2):679S-84S.
  2. Dreno B, Moyse D, Alirezai M, et al. Acne Research and Study Group. Multicenter randomized comparative double-blind controlled clinical trial of the safety and efficacy of zinc gluconate versus minocycline hydrochloride in the treatment of inflammatory acne vulgaris. Dermatology. 2001;203(2):135-40.
  3. Meynadier J. Efficacy and safety study of two zinc gluconate regimens in the treatment of inflammatory acne. Eur J Dermatol. 2000 Jun;10(4):269-73. PMID: 10846252.
  4. Momen-Heravi M, Barahimi E, Razzaghi R, et al. The effects of zinc supplementation on wound healing and metabolic status in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial. Wound Repair Regen 2017 May;25(3):512-520.
  5. Warthon-Medina M, Moran VH, Stammers AL, et al. Zinc intake, status and indices of cognitive function in adults and children: a systematic review and meta-analysis. Eur J Clin Nutr. 2015 Jun;69(6):649-61.
  6. Gonoodi K, Moslem A, Ahmadnezhad M, et al. Relationship of Dietary and Serum Zinc with Depression Score in Iranian Adolescent Girls. Biol Trace Elem Res. 2018 Nov;186(1):91-97.
  7. Solati Z, Jazayeri S, Tehrani-Doost M, Mahmoodianfard S, Gohari MR. Zinc monotherapy increases serum brain-derived neurotrophic factor (BDNF) levels and decreases depressive symptoms in overweight or obese subjects: a double-blind, randomized, placebo-controlled trial. Nutr Neurosci. 2015 May;18(4):162-8. 
  8. Baradari AG, Alipour A, Mahdavi A, et al. The Effect of Zinc Supplementation on Sleep Quality of ICU Nurses: A Double Blinded Randomized Controlled Trial. Workplace Health Saf. 2018 Apr;66(4):191-200.
  9. Wessels I, Maywald M, Rink L. Zinc as a Gatekeeper of Immune Function. Nutrients. 2017 Nov 25;9(12). pii: E1286. 
  10. Mocchegiani E, Romeo J, Malavolta M, et al. Zinc: dietary intake and impact of supplementation on immune function in elderly. Age (Dordr). 2013 Jun;35(3):839-60. 
  11. Barnett JB, Dao MC, Hamer DH, et al. Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2016 Mar;103(3):942-51.
  12. Read SA, Obeid S, Ahlenstiel C, Ahlenstiel G. The Role of Zinc in Antiviral Immunity. Adv Nutr. 2019 Jul 1;10(4):696-710.
  13. Hulisz D. Efficacy of zinc against common cold viruses: an overview. J Am Pharm Assoc (2003). 2004 Sep-Oct;44(5):594-603.
  14. Fernández-Cao JC, Warthon-Medina M, Hall Moran V, Arija V, Doepking C, Lowe NM. Dietary zinc intake and whole blood zinc concentration in subjects with type 2 diabetes versus healthy subjects: A systematic review, meta-analysis and meta-regression. J Trace Elem Med Biol. 2018 Sep;49:241-251.
  15. Ruz M, Carrasco F, Rojas P, et al. Nutritional Effects of Zinc on Metabolic Syndrome and Type 2 Diabetes: Mechanisms and Main Findings in Human Studies. Biol Trace Elem Res. 2019 Mar;188(1):177-188. 
  16. Beigi Harchegani A, Dahan H, Tahmasbpour E, et al. Effects of zinc deficiency on impaired spermatogenesis and male infertility: the role of oxidative stress, inflammation and apoptosis. Hum Fertil (Camb). 2020 Apr;23(1):5-16. 
  17. Gilbert R, Peto T, Lengyel I, Emri E. Zinc Nutrition and Inflammation in the Aging Retina. Mol Nutr Food Res. 2019 Aug;63(15):e1801049. 
  18. Wilson RL, Grieger JA, Bianco-Miotto T, Roberts CT. Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review. Nutrients. 2016 Oct 15;8(10):641
  19. Jafari F, JT Mohammad, Farhang A, Amani R. Effect of zinc supplementation on quality of life and sleep quality in young women with premenstrual syndrome: a randomized, double-blind, placebo-controlled trial. Arch Gynecol Obstet. 2020 Sep;302(3):657-664.
  20. Jafari F, Farhang A, JT Mohammad. Effect of Zinc Supplementation on Physical and Psychological Symptoms, Biomarkers of Inflammation, Oxidative Stress, and Brain-Derived Neurotrophic Factor in Young Women with Premenstrual Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial. Clinical Trial Biol Trace Elem Res. 2020 Mar;194(1):89-95.
  21. Bonaventura P, Benedetti G, Albarède F, Miossec P. Zinc and its role in immunity and inflammation. Autoimmun Rev. 2015 Apr;14(4):277-85.