Vitamin D in cutaneous carcinogenesis: part I

Abstract

Skin cancer is the most common cancer in the United States. Exposure to ultraviolet radiation is a known risk factor for skin cancer but is also the principal means by which the body obtains vitamin D. Several studies have suggested that vitamin D plays a protective role in a variety of internal malignancies. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar protective effect. These noncalcemic actions of vitamin D have called into question whether the current recommended intake of vitamin D is too low for optimal health and cancer prevention. Part I will review the role of vitamin D in the epidermis; part II will review the role of vitamin D in keratinocyte-derived tumors to help frame the discussion on the possible role of vitamin D in the prevention of skin cancer.

Fig 1

Vitamin D pathway.

Fig 2

Odds ratios of vitamin D deficiency comparing high frequency to low frequency users according to sun protective behaviors among whites in the United States. Data taken from National Health and Nutrition Examination Survey subjects who self-reported high versus low usage of shade, long sleeves, a hat, or sunscreen on a very sunny day (2003–2006). *Multivariate adjusted odds ratio of vitamin D deficiency comparing high usage of sun protection factor >40 sunscreen to sun protection factor <20 sunscreen. The symbols indicate the odds ratios, and the whiskers indicate the 95% confidence intervals.