Vitamin D has a reputation as a compound that can help bones stay strong. However, research has shown that immune system cells such as macrophages or monocytes rely on vitamin D as well (Reviews in Medical Virology, Jan. 2017). Many people may wonder if high-dose vitamin D could help people resist serious infections like COVID-19.
Can High-Dose Vitamin D Fight Infection?
Q. I have read that high-dose vitamin D did not make a difference when people were admitted to the hospital with COVID-19. Perhaps you should have higher levels of vitamin D circulating in your body when you are first exposed to COVID-19, instead of receiving a massive dose of D after you are already sick and in the hospital. Higher levels of D at the get-go might prevent the inflammation and immune system overreactions that make COVID-19 so serious for some people.
A. You are referring to a Brazilian study (MedRxiv, Nov. 17, 2020). In it, 240 hospitalized COVID-19 patients got either placebo or 200,000 IU of vitamin D in a single giant dose. There was no difference between the groups with respect to hospital stay, intensive care or ventilator use.
Low Vitamin D May Make People More Susceptible to COVID-19:
Other research suggests that people with low vitamin D levels in their bodies may be more vulnerable to COVID-19 (Health Security, Dec. 14, 2020). Vitamin D helps calm inflammation. As a result, some scientists hypothesize that people without enough vitamin D are more likely to suffer deadly cytokine storms if they become infected (Aging Clinical and Experimental Research, Sep. 2, 2020). In other words, they agree with you that people with adequate vitamin D before infection are better off than having sick people take super high-dose vitamin D.
You can learn more about vitamin D in our eGuide to Vitamin D and Optimal Health. In it, you’ll learn about supplementation and symptoms of inadequate vitamin D as well as details on what it does. Is high-dose vitamin D dangerous? We lay out its possible toxicity.
You may also wish to listen to our podcast on the topic. It is Show 1240: The Link Between Vitamin D and COVID-19. In it, we interview guest experts David O. Meltzer, MD, PhD, and Bruce Hollis, PhD.