Does Vitamin D Supplementation Reduces Mortality Rate and/or Improves Symptoms of Middle-Aged and Older Adults (Age 45 and Over) With COVID-19?

Abstract

Introduction Adults who are middle-aged and older are at an increased risk of contracting COVID-19 and at a greater risk of mortality than younger people. This systematic review aims to identify and synthesise evidence on the role of vitamin D treatment in reducing mortality as the primary outcome. As a secondary outcome, this review looks at vitamin D role in improving symptoms of COVID-19 in adults middle-aged and older (≥ 45 years). Methods Embase and MEDLINE were used for evidence up to 14 June 2021. Experimental studies, including intervention trials for participants ≥ 45 years that received vitamin D supplementations and the measured mortality or symptoms progression were included; otherwise, publications were excluded. Results Five papers were taken forward for further analysis. Only two of these studies reported a statistically significant decrease of 95.6% (p-value= <0.001) and 80% (p-value= 0.017) in mortality. The rest observed no effects, perhaps a trend towards mortality reduction. Additionally, four studies out of the five reported improvements in symptoms of COVID-19 patients, where COVID-19 severity decreased by 70% (p-value= 0.047), admission to intensive care units decreased by 92.3% (p-value= <0.001) and mechanical ventilation needs decreased by 81.3% (p-value= 0.006). The studies overall quality was moderate. Conclusion This review found little evidence of a trend of the effect of vitamin D in decreasing mortality and improving symptoms of middle-aged and older COVID-19 patients. While some evidence exists, further studies are needed before drawing definite conclusions due to the limited number of studies available at present.