Vitamin D₃ Deficiency and COVID-19

Multiple factors including advanced age, various co-morbidities, and vitamin D₃ deficiency are identified as associated with an increased risk and the severity of COVID-19. These and other associations will be useful in determining which COVID-19 factors are truly related to infection resistance, the severity of the disease, prevention, and therapy. As associations with COVID-19 are multidisciplinary and interdisciplinary, we call attention to the need for coordination and cooperation among journal editors, political groups, think tanks, granting agencies, scientific institutes, universities, and pharmaceutical companies. Purposeful encouragement for collaboration is needed also for scientists in disciplines including virology, molecular biology, infectious disease, medicine, pharmacology, epidemiology, mathematical modeling, and others. A scientific pandemic of effort is called for to defeat the COVID-19 pandemic.

In support of the vitamin D₃ association, we offer specific evidence. H. Lau and associates [1], in research not yet peer-reviewed, present new findings and cite published work with relevance to vitamin D₃ status and COVID-19. They found associations between demographics and risk factors for COVID-19 deaths and hospitalizations. This included being: elderly (˃65 years), African-American, hypertensive, obese, and male. More than 80% of African-Americans are reported to be vitamin D₃ deficient and in a Louisiana population, they accounted for 70% of COVID-19 deaths but represented only 32% of the population. Does increased skin melanin affect vitamin D₃ concentration sufficiently to account for this? Exposure to sunlight is reported to account for 80 to 90% of the body’s vitamin D₃ [2]; however, this obviously is confounded by other factors relative to the incidence and severity of COVID-19. It was reported that 100% of 147 COVID-19 positive subjects in a Boston homeless shelter were asymptomatic. It was speculated that this could be related to high sunlight exposure. Surely, more evidence is needed.

Recently, Parva and coworkers [3] concluded: “The prevalence of vitamin D₃ deficiency is greater in certain clinical subpopulations, and the presence of associated characteristics should raise the index of suspicion for the practic-ing clinician with regard to conditions associated with vitamin D₃ deficiency…” This association with vitamin D₃ deficiency is strengthened by specific factors. There is a logical mechanism of action, immune modulation, and the cytokine storm [4, 5]. It also is reported that vitamin D₃ deficiency exacerbates sinonasal inflammation [6], and the COVID-19 virus primarily invades through receptors on cells in the human nose. The increased susceptibility of nursing home patients is surely associated with co-morbidities and advanced age. However, Vitamin D₃ deficiency is prevalent in nursing home occupants because of diet and lack of exposure to sunlight. Currently, there are useful data about global and population-associated vitamin D₃ concentrations and COVID-19 cases and outcomes, and these data were categorized by age, gender, race, and other factors [7, 8]. Is the observed seasonality of the flu and coronavirus infections related primarily to temperature and humidity, or does sunlight act indirectly via synthesis of the precursor to vitamin D₃? It is possible and would be useful to assess whether vitamin D₃ deficiencies in certain populations (Italy, Spain) are correlated with observed increased rates of infection and death by COVID-19. This could be assessed by country and even within countries.

Vitamin D₃ is remarkably safe and is prescribed routinely at doses of 10,000 U (and higher). Research to assess the associations we have described is complex and crosses many scientific disciplines. Sufficient clues are present to merit a thorough, concerted, and coordinated effort to resolve the role of vitamin D₃ in COVID-19 by scientists, physicians, politicians and others in positions of power, influence, and authority. Answers are available and are needed urgently because of the threat of the COVID-19 pandemic.