Over 80 percent COVID-19 patients in a hospital in Spain have vitamin D deficiency, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.
Vitamin D is a hormone the kidneys produce that controls blood calcium concentration and impacts the immune system. Vitamin D deficiency has been linked to a variety of health concerns, although research is still underway into why the hormone impacts other systems of the body. Many studies point to the beneficial effect of vitamin D on the immune system, especially regarding protection against infections.
“One approach is to identify and treat vitamin D deficiency, especially in high-risk individuals such as the elderly, patients with comorbidities, and nursing home residents, who are the main target population for the COVID-19,” said study co-author José L. Hernández, Ph.D., of the University of Cantabria in Santander, Spain.
“Vitamin D treatment should be recommended in COVID-19 patients with low levels of vitamin D circulating in the blood since this approach might have beneficial effects in both the musculoskeletal and the immune system.”
The researchers found 80 percent of 216 COVID-19 patients at the Hospital Universitario Marqués de Valdecilla had vitamin D deficiency, and men had lower vitamin D levels than women. COVID-19 patients with lower vitamin D levels also had raised serum levels of inflammatory markers such as ferritin and D-dimer.
Why Your Liver and Kidneys Matter
Contrary to popular belief, vitamin D is not one chemical but many. When your body is exposed to sunlight (specifically ultraviolet B rays), the cholesterol in your skin cells start to produce vitamin D3. But the body can’t use this form of vitamin until it is further processed by the liver and kidneys.
The first stop is in the liver, where vitamin D is transformed into 25-hydroxyvitamin D, which is the same compound that doctors refer to when trying to measure vitamin D deficiencies. The next stop are the kidneys. At this point, 25-hydroxyvitamin D turns into 1,25 dihydroxyvitamin D, which is also known as the active form of the vitamin.
As mentioned above, vitamin D is best-known for keeping bones healthy. Without enough vitamin D, the body can only absorb 10-15% of dietary calcium and between 30-40% when in adequate supply.