Q: I recently went to Urgent Care with what turned out to be bronchitis. One of the doctor’s recommendations was to take a Vitamin D supplement; why?

A: A recent study of patients with respiratory illnesses thought to be COVID-19 was large enough to determine that higher Vitamin D levels were associated with less severe symptoms and more rapid recovery from COVID-19.

Perhaps more importantly, they learned that the patients who tested negative for COVID-19 and appeared to have a different virus, but had higher levels of Vitamin D, also had milder symptoms and recovered faster than the rest of the study participants who also tested negative for COVID-19.

It appears that trying to maintain higher levels of vitamin D, by consuming foods already high in this vitamin (nearly any seafood [including fresh water fish], pork, and mushrooms, provided they were grown in sunlight, not under a lamp) or enriched with this vitamin (dairy products, soy milk, almond milk), will help you avoid and suffer less from almost any respiratory infection.

Another way to increase vitamin D is to expose parts of your body to sunlight. This capability evolved in the human species tens of thousands of years ago, in the absence of other ways for land-locked populations, with little or no access to seafood, to survive many types of infections.

The skin on your back is particularly good at synthesizing Vitamin D. Allowing sunlight to strike your back for only 20 minutes, even through a window in the middle of the winter, will cause the production of 40,000 to 50,000 International Units (IU) of vitamin D, enough to keep your body well supplied for over a week.

Keep in mind that most pharmaceutical vitamin D supplements, generally taken once a week, contain this same amount of the vitamin, though not in 100% bioavailable form. It also doesn’t take much sun exposure on the face or arms (10-15 minutes 3-4 times a week), to have a similar effect. Of course, it is always good to avoid sunburn as much as possible.

I want to thank Randall P. for his question. To learn more about this and many other health topics, visit the American Academy of Family Physicians’ website familydoctor.org, where you can click on the Search box in the upper right corner of the website, and enter your topic of interest.

If you have a topic you would like to hear more about, message me at paulmdake@ gmail.com.

Dr. Paul Dake, a Newberry native, is a retired family physician. He lives in Pinconning, Michigan.