Healthy vitamin D levels may lower risk of severe COVID-19

Patients with healthy vitamin D levels may have a lower risk of developing and dying from severe COVID-19, according to a study published in PLOS One on September 25.

In the study, Maghbooli and colleagues analyzed the data of 235 patients with COVID-19 in Sina Hospital in Tehran, Iran, who had laboratory documentation of their 25(OH)D level at the time of hospitalization. The average age of the study participants was 58.7 years, and 37.4% were aged 65 years or older.

Among the participants, 74% had severe COVID-19 disease, and 32.8% were vitamin D sufficient, with 25(OH)D levels at or above 30 ng/mL. The researchers found that patients with healthy vitamin D levels had lower risks of becoming unconscious and hypoxic; significantly lower levels of serum C-reactive protein (CRP), an inflammatory marker; and higher total blood lymphocyte counts. No one younger than 40 years died from COVID-19 in the study. However, of the 206 patients aged 40 years and older, 16.3% succumbed to the disease. Of those who died, only 9.7% had sufficient vitamin D levels compared with 20% who had insufficient levels below 30 ng/mL.

These results suggest that healthy vitamin D levels improved patients’ immune response by “reducing risk for cytokine storm in response to this viral infection,” wrote the authors. They also noted that 6.3% of the patients who died had 25(OH)D levels of 40 ng/mL or higher, so “a blood level of at least 40 ng/mL may be optimal for vitamin D’s immunomodulatory effect.”

More studies are needed to understand the role of vitamin D status on the risk of acquiring COVID-19 and developing a severe disease. However, based on the available literature and this study’s results, the authors wrote that “it is reasonable to recommend vitamin D supplementation” to improve vitamin D status in the general population and possibly reduce the risk of acquiring COVID-19. Vitamin D supplementation may also reduce the risk of severe disease in patients who already have COVID-19, especially those who are hospitalized, they wrote.

The COVID-19 crisis continues to evolve rapidly. For the most up-to-date information and resources, visit the APhA Pharmacist’s Guide to Coronavirus at