What it does and deficiency
Zinc powers immune cells, cell division, and protein synthesis, making it key for wound healing and growth. Low zinc can cause a dulled sense of taste, poor appetite, slow-healing wounds, frequent infections, and thinning hair. Vegetarians, older adults, pregnant people, and those with GI disorders or alcohol use disorder are at higher risk.
Food and supplements
Oysters are by far the richest source, followed by beef, crab, pork, pumpkin seeds, and fortified cereals. Some meta-analyses show zinc lozenges started early shorten colds, but results are inconsistent and they can leave a bad taste or nausea. Taking more than 40 mg a day for long periods can cause copper deficiency, anemia, and weakened immunity. Zinc helps hair loss only if you're actually deficient.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- When should I take zinc?
- It absorbs best on an empty stomach, but take it with food if it upsets your stomach. Space it from iron and calcium supplements.
- Does zinc boost testosterone?
- Deficiency is linked to low testosterone, but extra zinc doesn't seem to help people who aren't deficient.
Sources reviewed: 2026-10-26
References
- National Institutes of Health Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals.
- Wessels, I., Maywald, M., & Rink, L. (2017). Zinc as a gatekeeper of immune function. Nutrients, 9(12), 1286.
- Hunter, J., et al. (2021). Zinc for the prevention or treatment of acute viral respiratory tract infections in adults: A rapid systematic review and meta-analysis. BMJ Open, 11(11), e047474.