Vitamin D and Coronavirus

 WattsUpWithThat summarizes recent scholarly work on the efficacy of vitamin D for alleviating and preventing COVID-19 infection.

Evidence that Vitamin D supplementation could reduce risk of influenza and COVID-19 infections and deaths (Grant et al., Nutrients, April 2, 2020) found that “through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines.”

The paper provided some interesting evidence that Vitamin D reduces Chinese-virus risk: “The outbreak occurred in winter, a time when 25-hydroxyvitamin D concentrations are lowest; the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration.”

This might also explain high rates of death among African-Americans:

Vitamin D deficiency is common not only in dark-skinned people, whose pigment blocks sunlight, but also in obese people, where the vitamin gets sequestered in fat cells; in those with Type 2 diabetes, where Vitamin D improves sensitivity to insulin; in the elderly, who avoid the sun and eat less; city dwellers, who see less of the sun; and men, who have lower Vitamin D levels than women in the winter. All of these groups are more likely to suffer severely if infected with the Chinese virus. ...

Patterns of COVID-19 Mortality and Vitamin D: An Indonesian Study (Rahasurun et al., April 26, 2020: https://ssrn.com/abstract=3585561) looked at 780 patients. “… the majority of the death cases were male and older and had pre-existing conditions and below-normal Vitamin D serum levels … with increasing odds of death. When controlling for age, sex, and comorbidity, Vitamin D status is strongly associated with COVID-19 mortality outcome …”

Vitamin D insufficiency is prevalent in severe COVID-19 (Lau et al., doi: https://doi.org/10.1101/2020.04.24.20075838) found that 11 of 13 intensive-care patients were deficient in Vitamin D, compared with only 4 of 7 not requiring intensive care. All Chinese-virus patients under 75 had Vitamin D deficiency.

Prevalence and correlates of Vitamin D deficiency in U.S. adults (Forrest & Stuhldreher, Nutr. Res., January 2011) studied almost 5000 patients and found that 42% were deficient in Vitamin D, but that 69% of Hispanics and 82% of black patients were deficient. “Vitamin D deficiency was significantly more common among those who had no college education, were obese, with a poor health status, hypertension, low high-density lipoprotein cholesterol level, or not consuming milk daily.”