With COVID-19 still raging war on our society, many are looking for a cure or a quick fix to prevent infection. Studies have been conducted to see if there is a connection between Vitamin D deficiency and COVID-19. The evidence, however, is thin. The National Institutes of Health says there is not enough evidence to show that vitamin D can prevent or treat COVID-19. Still, there is enough evidence that scientists are exploring the benefits of this and other supplements against the coronavirus1.
Vitamin D is critical for bone and mineral metabolism, but it also plays an essential role in the immune system. It is essential to regulating the body’s response to normal inflammation. It is known to support innate antiviral mechanisms and to regulate inflammatory responses associated with some respiratory infections.
Vitamin D deficiency is common in the US. JAMA Internal Medicine estimates that 75% of US adults and teens are chronically deficient. It is more prevalent among older people and African Americans, and the COVID-19 mortality rate in that population is greater. Additionally, Vitamin D deficiency is associated with chronic diseases, particularly diabetes and cardiovascular disease, which also affects COVID-19 severity. There could be a connection, but we don't have enough data to prove that one causes the other. Randomized controlled clinical studies would be required to prove causation.
Vitamin D is found in very few foods—fatty fish such as salmon, tuna, and mackerel have the highest levels. Mushrooms and egg yolks also contain small amounts. Foods like milk and cereals have been fortified with vitamin D. Because of its scarcity in food and beverages, taking supplements will provide an added boost.2
While we wait for results from trials, promoting efforts to raise Vitamin D intake to 4,000 IU/day (for children nine years and older, adults, and pregnant and lactating teens and women)3 indeed will benefit your bones and muscles. If there is a chance it may reduce the impact of COVID-19, especially among the population where Vitamin D deficiency is most prevalent, there is nothing to lose and potentially a lot to gain.