I have written previously about the importance of winter Vitamin D supplementation. Despite its importance, it’s estimated that anywhere from 30% to 80% of the U.S. population is vitamin D insufficient. A nutrient insufficiency differs from a deficiency in that a deficiency causes a disease, in the case of Vitamin D a deficiency causes rickets and osteomalacia. Vitamin D insufficiency doesn't cause a disease, but neither does it promote optimal health.
Vitamin D is a fat-soluble micronutrient that promotes calcium absorption, it also modulates cell growth, neuromuscular and immune function and reduces inflammation. There's a growing body of scientific analysis that is suggesting Vitamin D has an important influence on COVID-19 symptom severity.
This week in the scientific journal Nature a group of researchers published a study of vitamin D level among asymptomatic and critically ill COVID-19 patients.
The researchers compared people with asymptomatic infections to people with severe infections: 97 percent of people in the severe group had vitamin D deficiency vs. 33 percent in the asymptomatic group. The fatality rate was seven times higher in the low vitamin D group (21 percent vs. 3 percent).
All of these studies (there are over a dozen of them now) are observational studies that are correlative and don't prove a causal relationship between vitamin D deficiency and COVID-19 severity. However, the strength of the relationship might justify the inclusion of recommending vitamin D supplementation in public health advice.
I advocate vitamin D supplementation in the winter because :
Vitamin D is incredibly safe when taken at appropriate doses (up to 8,000 IU/d).
Vitamin D insufficiency is widespread in the industrialized world. It’s estimated that anywhere from 30% to 80% of the U.S. population is vitamin D insufficient.
Vitamin D is relatively cheap.
Vitamin D is readily available without a prescription.
The benefits of correcting vitamin D insufficiency are well established.
We might now add to this list that vitamin D could reduce the severity of COVID-19 symptoms. Of course, we can't out-supplement an unhealthy diet or lifestyle. So make sure you continue to eat whole unprocessed foods. drinks lots of water, and get daily exercise.
Record your WOD on Beyond the Whiteboard.
Do you need CrossFit or yoga gear? Click on the links below to buy through our Just Strong, Reebok, Rogue or Hylete Affiliate share sale programs. These are affiliate links and our gym will be compensated if you make a purchase after clicking on these links.
Check out our Flickr page!