Over 80% of 216 COVID-19 patients in a hospital in Spain had a deficiency in vitamin D, according to a new study published online in the Endocrine Society’s Journal of Endocrinology and Metabolism.
 
Vitamin D is a hormone produced by the kidneys which controls blood calcium concentration, and has an impact on immune system response. Deficiency in vitamin D, which is one of the most common nutritional deficiencies, has been linked to a variety of health issues, when it reaches severe stages, however, new research is elucidating the impact that more minor cases of deficiency might be linked to.
 
According to the study, 80% of the COVID-19 patients in the hospital had vitamin D deficiency, and men overall had lower vitamin D levels than women. The authors of the study linked low vitamin D levels to increased serum levels of inflammatory biomarkers, such as ferritin and D-dimer. Additionally, those with serum levels of vitamin D less than or equal to 20 ng/mL had longer hospital stays, and a greater prevalence of hypertension and cardiovascular diseases.
 
Because this was an observational study, no causative relationship between vitamin D levels and COVID-19 outcomes could be established by the authors.
 
“The interplay between vitamin D and viral infection is an area of growing interest, and interaction with host and viral factors, immunomodulatory effects, induction of autophagy and apoptosis, and even genetic and epigenetic factors have been reported as antiviral effects of this hormone,” the authors said. “Our study was carried out in a hospitalized population, and in this sense, it is worth mentioning that serum 25OHD has been considered as a negative acute-phase reactant and its values have been reported to be decreased during acute inflammatory diseases. Thus, our COVID-19 patients had a high prevalence of vitamin D deficiency, and serum 25OHD levels significantly and negatively correlated with ferritin and D-dimer values, indicating that vitamin D might have a beneficial role on the systemic inflammatory state of this viral disease.”
 
“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 COVID-19,” study co-author José L. Hernandéz said in the announcement of the publication. “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.”