Zinc supplementation might protect against colds and boost immunity in zinc-deficient individuals.
Zinc is a trace mineral needed for optimal bodily function. In terms of immunity, zinc has been shown to:
- Support immune function. Zinc is critical for the proper functioning of white blood cells and other parts of the immune system.
- Ward off colds. The latest research suggests that there is some truth to the belief that zinc supplements can help you get over a cold quickly.
Zinc is an essential mineral that our bodies need in small amounts to function properly. Just some of the fundamental processes zinc is involved in are protein & DNA production, cell division, and wound healing. However, zinc is better known for playing a critical role in the function of the immune system.
Indeed, many people believe that supplementing zinc can help ward off colds and other infections and illnesses. The only caveat is that zinc supplements are unlikely to do much if you already get enough zinc from your diet.
Although zinc deficiency is relatively rare in the developed world, certain populations – such as the elderly and vegetarians – do have an increased likelihood of not getting enough zinc. As such, they might see improved immune system function from zinc supplementation.
How Zinc Might Help With Immunity
Supporting optimal immune function
Zinc plays a critical role in virtually all aspects of the immune system. Zinc is needed for optimal function of the many different types of white blood cells that protect the body from illness and infection, in addition to cytokine production, phagocytosis, and other immune system processes.1 Even mild zinc deficiency can weaken the immune system, whereas severely zinc-deficient individuals suffer from constant infections that could even lead to death as early as 25 years of age.
Activation of the immune system results in increased generation of reactive oxygen species (ROS), which can in turn in damage immune system cells and processes. As an antioxidant compound, zinc can help neutralize this damage, indirectly improving immune system function.2
Zinc Immunity Uses & Benefits
Given it’s essential roles in the human body, zinc is supplemented to help with everything from testosterone production to vision loss. Similar to vitamin C, zinc is also commonly used to ward off cold and flu infections.
There is some scientific evidence that zinc can help with colds. In terms of boosting overall immune function, however, it seems that zinc only helps individuals with low zinc levels, such as older adults.
Human trials confirm that zinc supplementation can improve immunity in the elderly, and help ward off the common cold.
This randomized, double-blind, placebo-controlled study tested the immunity benefits of zinc supplementation in elderly participants. Fifty healthy adults (aged 55-87) received either zinc gluconate (45 mg) or placebo daily for 12 months. The trial found that the subjects had naturally lower zinc levels than younger adults, and that supplementation raised zinc levels along with a significant reduction in occurrence of infections and production of tumor necrosis factor alpha, a cytokine that promotes inflammation.
- The researchers concluded that “After zinc supplementation, the incidence of infections was significantly lower, plasma zinc was significantly higher, and generation of tumor necrosis factor alpha…was significantly lower.“5
This study examined the effect of zinc supplementation on the immune system of older adults. Fifteen people (aged older than 70) were given zinc sulfate (440 mg) daily for month and compared to 15 supplemented individuals. The study reported significant improvement of immune function, as shown by higher number of T cells, delayed hypersensitivity reactions, and antibody response to a vaccine.
- The researchers concluded that “the addition of zinc to the diet of old persons could be an effective and simple way to improve their immune function.“6
This systematic review sought to explain the mixed results of 13 studies looking at zinc use for the common cold. The researchers hypothesized that the reason some studies showed no benefit was because the zinc dosage was too low. They found that all 8 studies that used high doses (75+ mg) of zinc reported a significant reduction (20-42%) in the duration of colds.
- The researchers concluded that “Many trials with daily zinc doses of over 75 mg have found significant reduction in the duration of colds.“7
Dosage for Immunity
- Research suggests that around 45 mg zinc gluconate or 440 mg zinc sulfate can boost immunity
- Zinc doses of 75 mg or more appear to be effective for helping with colds
- Zinc acetate may be more effective for warding off colds than zinc gluconate
- Most single-ingredient zinc supplements supply doses of 30-50 mg zinc gluconate
Supplements in Review Says
- Zinc gluconate or zinc acetate 45-100 mg daily for immunity.
We recommend zinc for helping with cold infections, and for older adults looking to boost their overall immunity. Older individuals tend to have lower zinc levels, and research confirms that zinc deficiency can weaken the immune system.
Zinc gluconate or acetate are ideal. Most zinc supplements come in one of these two forms. If you’re looking for general immune system support zinc doses between 45 and 75 mg are sufficient; for getting over a cold, doses higher than 75 mg work best.
- Prasad AS. Zinc in Human Health: Effect of Zinc on Immune Cells. Mol Med. 2008 May-Jun; 14(5-6): 353–357. ↩
- Hughes DA. Effects of dietary antioxidants on the immune function of middle-aged adults. Proc Nutr Soc. 1999 Feb;58(1):79-84. ↩
- Prasad AS. Zinc deficiency in patients with sickle cell disease. Am J Clin Nutr. 2002 Feb;75(2):181-2. ↩
- Chandra RK. Excessive intake of zinc impairs immune responses. JAMA. 1984 Sep 21;252(11):1443-6. ↩
- Prasad AS et al. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress. Am J Clin Nutr. 2007 Mar;85(3):837-44. ↩
- Duchateau J et al. Beneficial effects of oral zinc supplementation on the immune response of old people. Am J Med. 1981 May;70(5):1001-4. ↩
- Hemila H. Zinc Lozenges May Shorten the Duration of Colds: A Systematic Review. Open Respir Med J. 2011; 5: 51–58. ↩