Vitamin D--the true and the false about vitamin D.

Vitamin D has a positive impact on our overall health. Also there are a few conditions with strong evidence for a protective effect of vitamin D, such as bone diseases, internal cancers, multiple sclerosis, hypertension and DM type 1. Skin is the major source of vitamin D through the action of UVB light on keratinocytes, although the biologically active form of vitamin D is not exclusively produced in the kidney but also in prostate, colon, skin and osteoblast where it acts as an autocrine or paracrine hormone. In the past decade raising incidence of skin cancers, especially melanoma and its connection with sun exposure lead to a sun protection policies and practices as part of the public health campaigns. The question is how much solar UV exposure is adequate to maintain the balance between the risk and the benefit. We as dermatologists have to raise public awareness of the potential health effects from excessive exposure to UV radiation but also we have to be aware that adequate blood level of vitamin D is necessary for optimal health. So future recommendation on sun protection have to balance between the risk and benefits of sun exposure, as well as to promote vitamin D supplementation as a safe alternatives in high risk population.