Vitamin D protects the skin?

Vitamin D generated by sunlight may help protect the skin from cellular damage, including damage caused by sunlight itself, suggests a new study published in this week's Nature Immunology. The researchers found that dendritic cells can convert vitamin D3 -- generated under the skin by sunlight -- into its active hormonal form, and induce T cells to migrate to the skin. "It's a new action for a chemical we've known to be present for a long time," said Clay Cockerell, a dermatologist at the University of Texas Southwestern Medical Center at Dallas, who was not involved in the study. "We may eventually find that [the T cell response] is protective in some way against skin cancer."However, this does not mean that more time in the sun is good for the skin, Cockerell stressed. On the contrary, he said, the study implies that excessive sun exposure could trigger a...