Approximately 50 percent of Americans are vitamin D deficient. The widespread use of sunscreens, reduced sun exposure, residence in northeastern US, and having more skin pigmentation, contributes to the high prevalence of vitamin D deficiency. Previous studies have found that vitamin D deficiency is associated with a decreased immune response and increased susceptibility to infection. Now research reports that vitamin D3 plays an important role in protecting the skin from infection and in wound healing.
The study, published in the Journal of Clinical Investigation, examined the effects of vitamin D3 on human keratinocytes (skin cells). Researchers at various institutions in California treated cultured human keratinocytes with the active form of vitamin D (1,25D3). The scientists also administered topical 1,25D3 to patients following skin injury. The in vitro and in vivo cell responses were analyzed.
The researchers found that the keratinocytes from a wound increased the expression of immunity genes, which increased production of cathelicidin (an antimicrobial protein). "These genes were induced by 1,25(OH)(2) vitamin D(3) (1,25D3; its active form), suggesting a role for vitamin D(3) in this process," the study authors write. The study results suggest that skin wounds require vitamin D3 to protect against infection and for healing.
"Thus, we demonstrate what we believe to be a previously unexpected role for vitamin D(3) in innate immunity, enabling keratinocytes to recognize and respond to microbes and to protect wounds against infection," the study authors conclude.
REFERENCES:
1. Schauber J et al. Injury enhances TLR2 function and antimicrobial peptide expression through a vitamin D-dependent mechanism. J Clin Invest 2007 Mar 1;117(3):803-811. Epub 2007 Feb 8.
Posted by Elaine Gavalas on March 12, 2007 12:24 PM
