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Supplement Monograph

Zinc

NutrientMineral

An essential trace mineral and cofactor for hundreds of enzymes — central to immunity, wound healing, growth and male hormone regulation.

Work in progress Updated February 2018

Where Does It Come From? (4)

Black Ant Polyrhachis spp. OysterPumpkin seedSesame

Overview

  • Zinc is the 23rd most common element in the earth’s crust 1Reference 1Mills · 2013Zinc in human biology.
  • Zinc is contained within every tissue/organ in the human body 1Reference 1Mills · 2013Zinc in human biology.
  • Zinc is the most common metal in the cytoplasm of the cell 1Reference 1Mills · 2013Zinc in human biology.
  • A zinc deficiency can reduce the expression of androgen (male hormone) receptors as well as testosterone production. This causes a reduction in the effects of testosterone from both sides, reducing existing testosterone’s ability to stimulate receptors, as well as lowering its production.
  • Studies on patients undergoing hemodialysis, who are notoriously known for having lowered zinc concentrations, were supplemented with zinc. They were noted to experience an 84% increase in testosterone after just 6 weeks 8Reference 8Jalali et al. · 2010Impact of oral zinc therapy on the level of sex hormones in male patients on hemodialysis. Animal studies found that regular zinc supplementation was able to boost testosterone levels even in healthy individuals 7Reference 7Kaya O et al. · 2006AnimalKaya O, et al. Zinc supplementation in rats subjected to acute swimming exercise: Its effect on testosterone levels and relation with lactate. Neuro Endocrinol Lett. (2006)..
  • Zinc content has been shown to have a direct correlation with testosterone in the body 6Reference 6Chang et al. · 2011Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue.
  • One of the highest concentrations of zinc in the body is the prostate 11Reference 11Wapnir · 1990Protein nutrition and mineral absorption.

Signs Of Deficiency

  • Growth Retardation
  • Lowered Immune Function
  • Loss of appetite
  • Hair Loss
  • Diarrhea
  • Low Libido
  • Impotence
  • Skin Lesions
  • Slow Wound Healing
  • Weight Loss
  • Mental Lethargy

Signs Of Excess

  • Nausea, vomiting and abdominal cramps
  • Loss of appetite and headaches
  • Copper deficiency with long-term high intake
  • Anaemia and lowered HDL (“good”) cholesterol
  • Suppressed immune function (doses ≥50 mg/day for weeks)

Food Sources Of Zinc

Oysters are by far the richest source. Other good sources include red meat, poultry, crab and other shellfish, beans, nuts and seeds (especially pumpkin seeds), whole grains and dairy. Zinc from animal foods is absorbed more readily than from plants, because the phytates in grains and legumes bind zinc and reduce its uptake — relevant for vegetarian and vegan diets.

Types Of Zinc Supplements

Chelated or “organic” forms — zinc picolinate, citrate, gluconate, acetate and monomethionine — are generally better absorbed than the inorganic forms zinc oxide and zinc sulfate. Zinc gluconate and acetate are the forms used in cold lozenges. Take zinc away from high-phytate meals and high-dose iron or calcium, and pair sustained high-dose zinc with copper to avoid a deficiency.

Pharmacology & Medical Research

Zinc & Muscle Growth

Zinc is found in every tissue and organ system in the human body, but the majority is found in the skeletal muscle tissues. Here we can find roughly 57% of all zinc content in the entire body 1Reference 1Mills · 2013Zinc in human biology.

The concentration of zinc in muscle tissue is a good indication of its importance for this organ system. One study investigating the effects of zinc deficiency on muscle growth found a significant reduction in growth rate in the zinc deficient group 12Reference 12Dørup et al. · 1991Effects of magnesium and zinc deficiencies on growth and protein synthesis in skeletal muscle and the heart. This makes perfect sense when you consider the fact that one of the primary side effects of zinc deficiency is slowed growth rates overall.

The reason for this is that zinc is required for the metabolism and synthesis of a protein known as leucine 12Reference 12Dørup et al. · 1991Effects of magnesium and zinc deficiencies on growth and protein synthesis in skeletal muscle and the heart. This protein was found to stimulate the growth of muscle tissue more than any other amino acid 13Reference 13Wagenmakers · 1998Muscle amino acid metabolism at rest and during exercise: role in human physiology and metabolism.

This makes zinc an essential supplement for the bodybuilder or athlete in order to allow for optimal muscle growth between exercises.

Zinc & Hormone Regulation

Males

In males, the amount of zinc contained in the body has been shown to have a direct correlation to the amount of testosterone 6Reference 6Chang et al. · 2011Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue. When zinc levels are low, researchers have discovered that testosterone activity decreases significantly. The reason for this is that zinc deficiencies lead to both a reduction in the receptors that testosterone works on (androgen receptors), as well as the production of testosterone itself, causing a double-ended reduction in testosterone function.

Females

In females, the relationship between zinc and hormone levels are slightly different. Zinc has been shown to inhibit overactivity of an enzyme known as 5-alpha-reductase, which is responsible for converting testosterone to the more active Dihydrotestosterone (DHT). This helps balance the ratio of estrogen to testosterone in the female body. This helps eliminate the symptoms of conditions related to hormonal imbalance such as hirsutism, PCOS, and PMS 14Reference 14Stamatiadis et al. · 1988Inhibition of 5α‐reductase activity in human skin by zinc and azelaic acid.

Zinc & Immune Function

One of the most common recommendations for zinc supplementation revolves around its ability to improve immune function. This includes wound healing, and resistance to colds and flus.

Zinc does this in a similar way to how it promotes muscle gain. It’s used as a cofactor for some of the critical enzyme reactions that our body uses to maintain our immune system.

To name a few, zinc is essential for the production of tumor necrosis factor alpha (TNF-a), Interleukin-2 (IL-2), and T-cells 2,3Reference 2Mantzoros et al. · 1998Zinc may regulate serum leptin concentrations in humansReference 3Fraker et al. · 2000The dynamic link between the integrity of the immune system and zinc status. The first two examples form the “alarm system”. They react to infections in the body to call in the heavy hitters like T-Cells to the area to clean it up. Zinc plays a key role in both the alarm and reaction phase of the immune response, which is what makes it so beneficial for keeping us healthy through cold and flu season.

In one study, adults infected with HIV were shown to be 50% more likely to have a zinc deficiency. The reason for this is the additional strain on zinc intake an immune condition causes the body. On top of this, those in the study who were deficient in zinc had a faster progression to AIDS 4Reference 4Baum et al. · 1997HIV-1 infection in women is associated with severe nutritional deficiencies.

Zinc & Wound Healing

Zinc is needed for collagen synthesis, cell division and the immune defences that operate at the site of an injury, so a deficiency measurably slows healing. Supplemental or topical zinc speeds repair mainly in people who are actually low in zinc — it is a corrective, not a booster for those already replete.

Other Nutrients

Zinc is best balanced against copper (high-dose zinc depletes it), and works alongside magnesium and vitamin B6. Browse the rest of the supplements database for related entries.

References

  1. Mills, C. F. (Ed.). (2013). Zinc in human biology. Springer Science & Business Media.
  2. Mantzoros, C. S., Prasad, A. S., Beck, F. W., Grabowski, S., Kaplan, J., Adair, C., & Brewer, G. J. (1998). Zinc may regulate serum leptin concentrations in humans. Journal of the American College of Nutrition, 17(3), 270-275.
  3. Fraker, P. J., King, L. E., Laakko, T., & Vollmer, T. L. (2000). The dynamic link between the integrity of the immune system and zinc status. The Journal of nutrition, 130(5), 1399S-1406S.
  4. Baum, M. K., Shor-Posner, G., Zhang, G., Lai, H., Quesada, J. A., Campa, A., … & Page, J. B. (1997). HIV-1 infection in women is associated with severe nutritional deficiencies. JAIDS Journal of Acquired Immune Deficiency Syndromes, 16(4), 272-278.
  5. Graham, N. M., Sorensen, D., Odaka, N., Brookmeyer, R., Chan, D., Willett, W. C., … & Saah, A. J. (1991). Relationship of serum copper and zinc levels to HIV-1 seropositivity and progression to AIDS. Journal of acquired immune deficiency syndromes, 4(10), 976-980.
  6. Chang, C. S., Choi, J. B., Kim, H. J., & Park, S. B. (2011). Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue. Biological trace element research, 144(1-3), 264-271.
  7. Kaya O, et al. Zinc supplementation in rats subjected to acute swimming exercise: Its effect on testosterone levels and relation with lactate. Neuro Endocrinol Lett. (2006).
  8. Jalali, G. R., Roozbeh, J., Mohammadzadeh, A., Sharifian, M., Sagheb, M. M., Jahromi, A. H., … & Afshariani, R. (2010). Impact of oral zinc therapy on the level of sex hormones in male patients on hemodialysis. Renal failure, 32(4), 417-419.
  9. Prasad, A. S. (2003). Zinc deficiency: has been known of for 40 years but ignored by global health organisations.
  10. Cherasse, Y., & Urade, Y. (2017). Dietary Zinc Acts as a Sleep Modulator. International journal of molecular sciences, 18(11), 2334.
  11. Wapnir, R. A. (1990). Protein nutrition and mineral absorption. CRC Press.
  12. Dørup, I., & Clausen, T. (1991). Effects of magnesium and zinc deficiencies on growth and protein synthesis in skeletal muscle and the heart. British Journal of Nutrition, 66(3), 493-504.
  13. Wagenmakers, A. J. (1998). Muscle amino acid metabolism at rest and during exercise: role in human physiology and metabolism. Exercise and sport sciences reviews, 26, 287-314.
  14. Stamatiadis, D., Bulteau‐Portois, M. C., & Mowszowicz, I. (1988). Inhibition of 5α‐reductase activity in human skin by zinc and azelaic acid. British Journal of Dermatology, 119(5), 627-632.
  15. Institute of Medicine, Food and Nutrition Board. (2001). Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press.