In 2020, our lives changed due to the COVID-19 pandemic. Thanks to science, multiple vaccines are out and showing good results (e.g., https://www.nejm.org/doi/full/10.1056/NEJMoa2034577). As it may be a while before the general population gets access, what can we do to stay healthy during this time? Aside from the social distancing, washing hands and wearing a mask, we can also get more vitamin D. This is a great chance to make a change in the new year: to get outside more, into the sunshine, and to eat healthy to give your body the best chance at boosting its natural defenses. Research is showing that vitamin D can also help prevent an exaggerated inflammatory response, which has been shown to contribute to severe illness in some people with COVID-19.
Your body needs vitamin D as its main job is to help the body absorb calcium from the intestines, where that calcium is necessary to help “mineralize” your bones – keeping them strong and healthy. Our bodies make vitamin D when exposed to sunshine. “We each have vitamin D receptor cells that, through a chain of reactions starting with conversion of cholesterol in the skin, produce vitamin D3 when they’re exposed to ultraviolet B (UVB) from the sun,” says Yale Medicine dermatologist Dr. David J. Leffell. Given winter sunlight doesn’t always contain enough UVB radiation, depending on location (e.g., here’s a study done in the UK: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121420/), you do need to pair your vitamin D intake with nutritional food and sometimes supplements.
Good food sources include fish (tuna, mackerel, and salmon), foods fortified with vitamin D (such as cereals and orange juice) and egg yolks. The recommended dietary dose of vitamin D is 600 IU (15 micrograms) each day for adults under age 70 and 800 IU (20 micrograms) each day for adults over 70.
Though, as always in science, more research remains to be done, the studies below provide more detail about the links already being found between vitamin D deficiency and COVID-19 risks:
“Low vitamin D levels have been associated with an increase in inflammatory cytokines and a significantly increased risk of pneumonia and viral upper respiratory tract infections.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385774/
“In this single-center, retrospective cohort study, likely deficient vitamin D status was associated with increased COVID-19 risk, a finding that suggests that randomized trials may be needed to determine whether vitamin D affects COVID-19 risk.”
“Vitamin D deficiency is more common in older age groups, smokers, those who are obese, and in patients with chronic diseases such as diabetes, hypertension, various gastroenterological diseases, and also in African Americans.1 The high-risk groups that have more complications and higher mortality in COVID-19 coincide with groups that have a high incidence of vitamin D deficiency. We believe that vitamin D deficiency might be one of the important risk factors for COVID-19 complications and higher mortality.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275153/