Effects of Ultraviolet Light on Skin Cholesterol

Surprisingly little is known of the photochemical reactions which occur in human skin upon exposure to sunlight. There are a few noteworthy exceptions, such as the activation of tyrosine, the general assumption of the conversion of 7-dehydrocholesterol to Vitamin D, the transformations in porphyrins which result in skin photosensitization, and the reduction in sulfhydryl linkages (1-4).