Vitamin D may offer some protection against coronavirus

  • Vitamin D supplements may help keep you healthy against COVID-19.

    Vitamin D supplements may help keep you healthy against COVID-19. Stock Photo

Updated 8/2/2020 9:23 AM

It may seem COVID-19 is an undefeatable virus. It is indeed resistant to many medications and seems to be unyielding to the human immune system.

Early on in this pandemic there was some research suggesting vitamin D deficiency increased the risk and severity of COVID infection. Conversely, robust vitamin D levels offered some protection from infection and may reduce the risk of serious complications. A recent medical study from Israel adds credence to vitamin D being protective.


Although we call vitamin D a vitamin, it is in reality a hormone that begins in the skin and is transformed by other organs to its final form. Vitamin D is best known for its effects on increasing bone mass. It also has a number of important roles in the functioning of the immune system, especially T cells. T cells are one part of the immune system that appears to be important in fighting the COVID-19 virus. Vitamin D also impacts the nervous, endocrine, cardiac, gastrointestinal, epithelial and pulmonary systems.

Many will say that we can get vitamin D from sun exposure and that is true. However, the exposure needs to be lengthy and during the heat of the day. For maximum benefit, as much skin should be exposed as possible. This flies in the face of dermatologists who tell us sun exposure leads to cancer, recommending sun-blocking agents, clothes and sun avoidance, which makes vitamin D deficiency common.

A recent medical study to be published in FEBS Journal involved more than 7,000 people who tested positive and over 7,000 people who tested negative for COVID-19. Adjusting for other factors such as age and gender, those with lower vitamin D levels tested positive more often and had more serious outcomes when compared to those who had more robust vitamin D levels. Low vitamin D levels were defined as less than 30 nanograms/milliliter. On average, those who tested positive for COVID-19 had vitamin D levels at 19 nanograms/milliliter. Currently there are at least 20 medical studies indicating the importance of vitamin D in preventing and treating COVID-19.

Living in northern Illinois puts us at increased risk of suboptimal vitamin D levels. The sun is intense enough only for about five months of the year. A sunny day in December will produce no vitamin D at all. Many of my patients will present with vitamin D levels below 30 but optimal blood levels seem to be in the 78 nanograms/milliliter range. We do not get enough sun exposure to reach these levels.

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Vitamin D in milk and other foods are too low to be of real benefit. The only option are vitamin D supplements. Vitamin D supplementation is safe and overdosing is exceedingly rare. Knowing the blood level of vitamin D is critical because some people will absorb it well and others may barely absorb it at all.

Vitamin D supplementation seems a simple way to move the odds in your favor with COVID-19.

Vitamin D does not make you immune to COVID-19, so continue safe distancing and face masks.

• Dr. Patrick Massey is medical director of complementary and alternative medicine at Alexian Brothers Hospital Network, and president of ALT-MED Medical and Physical Therapy, 1544 Nerge Road, Elk Grove Village.

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