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.
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