Zinc

Zinc is an essential trace mineral. Good food sources of zinc include: beef, poultry, baked beans, yogurt, milk, cashews and almonds.1 The 100% Daily Value for Zinc (based on 2000 kcal diet) is 15 mg,but it has been revised to 11 mg as of May 27, 2016.The 100% Daily Value for pregnant or lactating women is 13 mg, effective as of July 26, 2018.8

Forms

  • Zinc Gluconate: Zinc gluconate is prepared by combining a zinc compound with gluconic acid, an organic acid produced by the fermentation of glucose from corn.
  • Zinc Glycinate: Zinc glycinate is a bioavailable source of the essential mineral zinc. It is made by binding zinc obtained from the mineral salt, zinc sulfate, with the amino acid, glycine.
  • Zinc Oxide: Zinc oxide is prepared by boiling zinc that has been refined from zinc ore to form a zinc vapor. The vapor is oxidized, using a heated air process, to create zinc oxide powder.

Major Health Benefits

Zinc is a component of over 70 different enzymes in the human body, whose functions range from the creation genetic materials (DNA and RNA) to helping with the metabolism of fatty acids, amino acids, and protein. Zinc is part of superoxide dismutase (SOD), one of the body’s natural antioxidant enzymes. Zinc is also involved in normal immune function and contributes to growth and maintenance of normal bones, nails, hair, skin, and vision3. Zinc contributes to normal fertility and reproduction by maintaining normal testosterone levels.4,5 In addition, Zinc aids vitamin A metabolism and helping to contribute to normal vision and cognitive function, via its regulation of nerve cell signaling and nerve impulse transmission.4,5

Cautions

The Tolerable Upper Intake Level of Zinc per day is 40 mg.6 Excessive intake of Zinc may cause nausea, headaches, abdominal pain, diarrhea, and vomiting.7

References

  1. Higdon, J. Zinc. Linus Pauling Institute, Oregon State University. 2001. (Reviewed by Ho, E in 2013) (Food Sources) http://lpi.oregonstate.edu/mic/minerals/zinc Accessed 7/2015.
  2. US Food and Drug Administration. Guidance for Industry: A Food Labeling Guide (14. Appendix F: Calculate the Percent Daily Value for the Appropriate Nutrients). US Department of Health and Human Services. 2013 January.
  3. European Food Safety Authority.Scientific Opinion on the substantiation of health claims related to zinc and maintenance of normal skin, DNA synthesis and cell division, contribution to normal protein synthesis, maintenance of normal serum testosterone concentrations, “normal growth”, reduction of tiredness and fatigue, contribution to normal carbohydrate metabolism, maintenance of normal hair, maintenance of normal nails, and contribution to normal macronutrient metabolism. EFSA Journal 2010; 8(10): 1819.
  4. Higdon, J. Zinc. Linus Pauling Institute, Oregon State University. 2001. (Reviewed by Ho, E in 2013) (Regulatory Role)
  5. European Food Safety Authority. Scientific Opinion on Zinc Health Benefits. EFSA Journal 2009; 7(9): 1229.
  6. Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels, Elements. Food and Nutrition Board, Institute of Medicine, National Academies. (PDF available)
  7. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. The National Academic Press. 2001. (pp. 482)
  8. US Food and Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels. US Department of Health and Human Services. Federal Register / Vol. 81, No. 103, p. 33982 / May 27, 2016. https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf