Vitamin D and Cathelicidin Concentrations in Elite Irish Athletes

Cathelicidin (LL-37, hCAP18) concentrations are partially modulated in vivo by vitamin D. This potent antimicrobial peptide is involved in numerous antifungal, antiviral and antibacterial processes, which has led to its recognition as an important contributor to upper respiratory host defence. Recent research has implicated 1, 25-dihydroxyvitamin D3 (1, 25(OH)2D3) in cathelicidin biosynthesis, via vitamin D receptor complex-driven epigenetic modifications to the cathelicidin gene(2, 3). [...]results indicate that maintenance of vitamin D status over the winter months, with vitamin D3 supplementation, may attenuate the wintertime decrease in cathelicidin concentrations.