As we race to develop effective treatments and a vaccine against COVID-19, people are looking to reduce their risk of getting sick. One thing that might help is as obvious as the sun in the sky and as close as our medicine cabinet—Vitamin D. Former CDC chief, Dr. Tom Frieden, believes that coronavirus infection risk may be reduced by Vitamin D.
Vitamin D supplementation reduces the risk of respiratory infection, regulates cytokine production, and can limit the risk of other viruses such as influenza. A respiratory infection can result in cytokine storms—a vicious cycle in which our inflammatory cells damage organs throughout the body. This is what increases mortality for those with COVID-19. There is more and more proof that adequate Vitamin D may potentially provide some modest protection for vulnerable populations. This is especially important for people who are Vitamin D deficient—and, surprisingly, that might include more than 40 percent of U.S. adults. People who live in the northern part of the U.S. are at greater risk of deficiency.
There is evidence of seasonality in some respiratory illnesses, including influenza and tuberculosis. A leading hypothesis is that seasonality is due to the reduction in Vitamin D because of decreased exposure to sunlight in winter months. There is no seasonality of influenza or tuberculosis in some tropical climates, where weather—and sunlight exposure—remains constant throughout the year.
Dr. Frieden recommends that we seek to improve our resistance to infection. These include getting regular physical activity, getting enough sleep, stopping smoking and other tobacco use, and, for people living with diabetes, getting it under control. Taking a multivitamin that includes Vitamin D, or a Vitamin D supplement, might actually help.