Can Vitamin D and L-Cysteine Co-Supplementation Reduce 25(OH)-Vitamin D Deficiency and the Mortality Associated with COVID-19 in African Americans?

Abstract

Early reports indicate an association between the severity of the COVID-19 infection and the widespread 25-hydroxy vitamin D deficiency known to exist in populations around the world. Vitamin D deficiency is extremely common among African American (AA) communities, where the COVID-19 infection rate is three-fold higher, and the mortality rate nearly six-fold higher, compared with rates in predominantly white communities. COVID-19 infection primarily affects the lungs and airways. Previous reports have linked 25-hydroxy vitamin D deficiency with subclinical interstitial lung disease. AA are at risk for lower cellular glutathione (GSH) levels, and GSH deficiency epigenetically impairs VD biosynthesis pathway genes. Compared with vitamin D alone, co-supplementation of vitamin D and L-cysteine (a GSH precursor) showed a better efficacy in improving levels of GSH and VD-regulatory genes at the cellular/tissue level, increasing 25(OH) vitamin D levels, and reducing inflammation biomarkers in the blood in mice studies. We propose that randomized clinical trials are needed to examine the potential of co-supplementation with anti-inflammatory antioxidants, vitamin D and L-cysteine in correcting the 25(OH)VD deficiency and preventing the ‘cytokine storm,’ one of the most severe consequences of infection with COVID-19, thereby preventing the adverse clinical effects of COVID-19 infection in the vulnerable AA population.

Keywords:

• Vitamin D
• glutathione
• COVID-19
• L-cysteine
• African American

Acknowledgments

The Malcolm W. Feist Endowed Chair in Diabetes provided support to SKJ. RP is supported by the cardiovascular Research Fellowship from the Center for Cardiovascular Diseases and Sciences (CCDS) LSUHSC-Shreveport. SKJ also received support from grants from the National Institutes of Health/National Center for Complementary and Integrative Health (RO1 AT007442, 1R33 AT010637). The authors thank Ms. Georgia Morgan for excellent editing.

Disclosure statement

The authors declare no competing interests.