Senior Airman Michael Cossaboom, 20th Fighter Wing Public Affairs photojournalist, pretends to eat the sun during a sunrise in Asheville N.C., April 18, 2016. Finding ways to enjoy the workday keeps morale high for Airmen and their counterparts.

Back in March, former CDC director Tom Frieden, MD, published an opinion piece stating that taking Vitamin D supplements could help boost the immune system and protect against respiratory infection. It appears he was really on to something because now researchers all over the world are urging their governments to issue guidance on vitamid D supplementation to combat COVID-19.

Why is Vitamin D so important right now?

Higher COVID-19 mortality rates among older people and those with chronic conditions suggest that a weakened immune system contributes to poor outcomes. Science supports the possibility that Vitamin D may strengthen the immune system, particularly of people whose Vitamin D levels are low.

Immune benefits of Vitamin D supplementation:

  • reduces the risk of respiratory infection
  • regulates cytokine production
  • 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 – which increase mortality for those with COVID-19. Adequate Vitamin D may potentially provide some modest protection for vulnerable populations.

How much Vitamin D should I take?

The FDA recommendation of 400 IU daily is based on the fact that one teaspoon (5 ml) of most cod liver oils contains 400 IU of Vitamin D. What’s the significance of a teaspoon? That was the amount of cod liver oil that was shown to prevent rickets in children in northern latitude countries including Norway, Finland, and Sweden. “A teaspoon a day keeps the rickets away” was the saying. At the time it was believed that rickets was the only disease associated with vitamin D deficiency and therefore the recommendation of 400 IU was adopted. We now know that vitamin D deficiency is associated with more morbidities than just rickets.

Vitamin D deficiency can lead to:

Research suggests there is little risk associated with taking around 5,000 IU of vitamin D3 daily, but some people may do best with a higher or lower amount depending on their health status. These studies indicate that up to 10,000 IU per day typically causes no adverse reactions.