Supplements promising to enhance your immune system are a common sight in stores, often marketed in brightly colored bottles of pills and gummies, the New York Times reports.
For many, the temptation to try these products is strong, especially given the widespread belief that they can help prevent illness or lessen symptoms. Recent research shows that millions of Americans have turned to dietary supplements for immune support, with about one in nine US residents using them between January 2017 and March 2020, according to a study published in JAMA Network Open.
But are these supplements truly effective in boosting immunity, or are they just another health fad?
While the idea of supplements supporting the immune system seems reasonable—since many contain vitamins and minerals crucial for immune function—the reality is more complex. Some nutrients, such as vitamins A, C, D, and zinc, are indeed essential for immune defense, and deficiencies in these can increase the likelihood of infections, said Dr. Mahtab Jafari, a professor at the University of California, Irvine. However, most people in the US obtain adequate levels of these nutrients through a balanced diet, meaning supplements may not offer additional benefits for those already getting enough, according to Dr. Michael Ben-Aderet, associate medical director of hospital epidemiology at Cedars-Sinai in Los Angeles.
Many immune-supporting supplements contain a mix of ingredients, with vitamin D, vitamin C, and zinc being among the most studied. However, the scientific evidence supporting their effectiveness is inconsistent. Research on vitamin D supplements, for instance, has yielded mixed results. Some studies suggest a slight reduction in the risk of acute respiratory infections, but others found no protective benefit in those with normal or high vitamin D levels. Similarly, while vitamin C is often taken to prevent colds, a 2013 review found no evidence that it prevents infections, although it may slightly reduce the duration of symptoms. Zinc supplements show similar results, with studies indicating they don’t prevent the common cold but may shorten its duration.
Other popular ingredients, like elderberry and echinacea, are used in immune-boosting products, but there is even less research supporting their effectiveness in preventing or treating viruses. According to Dr. Jen Wall Forrester, senior medical director of infection prevention at UC Health, immunity is a complex process, and no single supplement is likely to have a significant impact.
The main reason it’s difficult to determine the real effects of these supplements is the lack of high-quality research. There are few rigorous randomized clinical trials, which are the gold standard in medical research, assessing their effectiveness. Furthermore, the dietary supplement industry is not regulated by the Food and Drug Administration (FDA) before products hit the market, meaning companies can sell items that haven’t been thoroughly tested for efficacy. A 2022 study of 30 immune-supporting supplements found that many had inaccurate labels or contained ingredients not listed on the packaging.
Experts caution consumers to approach immune-boosting supplements with skepticism. Dr. Ben-Aderet advises that it’s essential to question the claims made by supplement manufacturers and to look for products with third-party seals of approval, such as those from US Pharmacopeia or NSF, which test the quality of supplements. Additionally, checking the FDA’s website for warnings about specific brands can help avoid misleading products.
Before starting any supplement regimen, health professionals recommend consulting with a healthcare provider. They can help assess whether you have any deficiencies, advise on appropriate dosages, and ensure there are no harmful interactions with other medications. While some supplements may be safe to try, Dr. Wall Forrester cautions that without clear evidence of benefit, you might be wasting your money.
