Key Points

• Studies describing the relationship between UVB exposure, sunlight, and vitamin D on the incidence of colon, breast, ovarian, and other cancers have been published by the Garland brothers and other authors, with a recurring theme of decreased cancer risk with increased UVB and vitamin D; a study by Munoz and Grant found a significant association between increased solar radiation and and a decreased incidence of 23 different types of cancer
• A significant dose-response correlation between UV exposure and breast cancer risk was found in one study, such that women in the highest exposure groups had a 30% lower risk of breast cancer compared to women in the lowest exposure groups; overall, this study saw a negative correlation between UV exposure and breast cancer risk, especially among women over 40 years of age, and women who did not tan or who covered their arms and legs while in the sun also had a higher risk of breast cancer
• A detailed analysis of studies on sun exposure and melanoma and found that continuous, regular sun exposure was not associated with melanoma, but rather, sunburn doubled the risk of developing melanoma and intermittent, high-intensity sun exposure proposed a 61% increased risk for melanoma