Vitamin D is really more than just a vitamin and has many important jobs in your body. It keeps your bones strong by helping your body absorb calcium and phosphorus. Vitamin D allows your muscles to move efficiently, and nerves need it to carry messages throughout your body.
Vitamin D is also crucial for a healthy functioning immune system. Immune System cells including B cells and T cells actually have receptors for vitamin D and rely on the vitamin to function properly. Prior research has suggested a link between vitamin D and a decrease in viral respiratory infections including the ‘common cold’.
Vitamin D deficiency could be one of many factors involved in determining outcome of COVID-19, but it’s a problem that can be corrected safely and cheaply. Risk of Vitamin D deficiency correlates with many other COVID-19 risk factors including age, obesity, diabetes, and chronic illness. A growing body of circumstantial evidence now also specifically links outcomes of COVID-19 and vitamin D status. Certain populations including African-American and Hispanics not only have disproportionate morbidity and mortality from COVID-19, but also high rates of vitamin D deficiency. There seems to be very little downside to addressing and correcting Vitamin D levels in at-risk populations.
A recent University of Chicago study published in JAMA Network Open found that patients with “likely deficient” vitamin D status had nearly doubled risk of testing positive for COVID-19 versus those with “likely sufficient” vitamin D, a single-center study found. There is a lot of research to still be done, but Vitamin D supplementation could be especially important for older people since they are at high risk of both poor outcome from COVID-19 and vitamin D deficiency.
How can you get vitamin D?
It’s best to get vitamin D from sunlight and food, but you can also get it in a supplement. Only a small proportion of vitamin D comes from the food we eat, but it is still important to include vitamin D rich foods in your diet. Few foods contain significant amounts of Vitamin D naturally, including: fatty fish like salmon, tuna, and mackerel; beef liver, cheese, and egg yolks; and mushrooms have a small amount. Foods fortified with vitamin D in the US include milk, breakfast cereal, and some orange juice, yogurt, and soy drinks.
Sunlight is the best natural source of Vitamin D. Your body produces Vitamin D when the sun shines directly on your skin. Just 10 to 15 minutes of sunlight without sunscreen a couple of times a week is usually sufficient to maintain normal vitamin D levels. Always take care not to burn, especially during the strong sunshine in the middle of the day. Even on cloudy days, your body can still produce Vitamin D from sunlight but it can take a little longer. Speak with your physician about the specific amount of sun exposure recommended for you each week.
If you are 65+ years, not exposed to much sun or a pregnant or breast-feeding woman, or have been diagnosed with Vitamin D deficiency, your physician may advise or prescribe a daily vitamin D supplement.
