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Zinc is an essential mineral and can be found in high amounts in oysters, crabs and other meat products. Zinc is the second most abundant trace mineral in the body, needed for approximately 100 enzymatic reactions. The human body cannot produce zinc on its own, so we need to obtain it through diet. This mineral impacts wound healing, DNA synthesis, immune function, protein absorption and cell division. Zinc deficiency can cause impaired sense of taste and smell, impotence in men, diarrhea, poor night vision, and weight loss.

Immune system

In 2008, fifty volunteers were recruited within 24 hours of developing symptoms of the common cold. They were randomly assigned to a placebo group or a treatment group receiving zinc. This double-blind study gave the zinc group 13.3mg of zinc every 2-3 hours during the waking day. Compared with the placebo group, the zinc group had a shorter mean overall duration of cold (4.0 vs. 7.1 days), shorter duration of cough (2.1 vs. 5.0 days), and shorter duration of nasal discharge (3.0 vs. 4.5 days). Antioxidant and anti-inflammatory markers were also improved in the zinc group. While these results are promising, it should be noted that subjects received a high amount of zinc in response to acute cold symptoms that should not be taken on a daily basis.

In 2007, a 12 month, double-blind, placebo-controlled study was conducted on elderly patients to determine the effect of zinc on the immune system. After zinc supplementation, the incidence of infections among the treatment group was significantly lower, plasma zinc was significantly higher, and oxidative stress markers were significantly lower in comparison to the placebo group.

  1. Duration and severity of symptoms and levels of plasma interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor, and adhesion molecules in patients with common cold treated with zinc acetate.

    Prasad AS, Beck FW, Bao B, Snell D, Fitzgerald JT., The Journal of Infectious Diseases, 2008

  2. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress.

    Prasad AS, Beck FW, Bao B, Fitzgerald JT, Snell DC, Steinberg JD, Cardozo LJ., The American Journal of Clinical Nutrition, 2007

Zinc and Digestion

Indigestion is defined as a feeling of fullness, bloating, belching, aching and/or gas shortly after eating. It is believed that indigestion can often be linked back to lowered stomach acid (1,2).

Zinc is a mineral needed by both the immune system and digestive system, and is obtained through a varied diet. When it comes to digestion, zinc helps support the production of hydrochloric acid in the stomach.* Sufficient hydrochloric acid is needed to help break food down, especially proteins. This initial breakdown of food in the stomach allows for proper absorption in the small intestine. Those who experience occasional indigestion may benefit from additional zinc, since these symptoms may be associated with decreased levels of hydrochloric acid (3,4).

  1. Implications of Low Stomach Acid: An Update

    Banoo H. and Nusrat N., RAMA Univ. J. Med Sci, 2016

  2. Patient Care and Health Information: Indigestion

    Mayo Clinic, Mayo Foundation for Medical Education and Research (MFMER), 2011

  3. Zinc and gastrointestinal disease

    Skrovanek S, et al., World J Gastrointest Pathophysiol , 2014

  4. Zinc: Fact Sheet for Health Professionals

    National Institutes of Health Office of Dietary Supplements, National Institutes of Health Office of Dietary Supplements, 2020

Zinc and Vegetarian/Vegan

Additionally, since animal protein is one of the primary sources of zinc in the western diet, those who are vegetarian or vegan are at a greater risk for zinc insufficiency. It is estimated that vegetarians may require up to 50% more of the RDA of zinc than non-vegetarians (1).

  1. Zinc: Fact Sheet for Health Professionals

    National Institutes of Health Office of Dietary Supplements, National Institutes of Health Office of Dietary Supplements, 2020