Exposure of skin to ultraviolet radiation from sunlight presents both positive and negative health effects. On the positive side, UV exposure enables the synthesis of vitamin D3, which is essential for bone health[1] and potentially plays a role in inhibiting certain cancers.[2][3] While vitamin D can also be obtained through dietary supplements,[4] UV exposure offers benefits such as enhanced subdermal nitric oxide production and improved endorphin levels, which are not achievable through supplementation alone.[5][6][7][8][9] Additionally, exposure to visible light supports melatonin synthesis, maintains circadian rhythms, and reduces the risk of seasonal affective disorder.[10]
However, UV radiation is also a mutagen and carcinogen for the skin, posing significant risks.[11][12] Acute exposure can lead to painful sunburns and increase the likelihood of developing serious skin conditions later in life.[13] Prolonged exposure is associated with the development of skin cancers, photoaging or premature skin aging, immune suppression, and eye diseases like cataracts.[14][15]
Given these dual effects, public health organizations emphasize the importance of striking a balance between the benefits and risks of UV exposure. They recommend avoiding sunburn at all costs and advocate for moderation in sun exposure to minimize the risks associated with UV radiation while still reaping its health benefits.[16]
^John EM, Schwartz GG, Koo J, Van Den Berg D, Ingles SA (June 2005). "Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer". Cancer Research. 65 (12): 5470–5479. doi:10.1158/0008-5472.can-04-3134. PMID15958597.
^Egan KM, Sosman JA, Blot WJ (February 2005). "Sunlight and reduced risk of cancer: is the real story vitamin D?". Journal of the National Cancer Institute. 97 (3): 161–163. doi:10.1093/jnci/dji047. PMID15687354.