Vitamin D production and the impact of sun exposure

Sun exposure is the primary source of vitamin D for most people, as UVB rays convert 7-dehydrocholesterol in the skin into vitamin D3. However, several factors influence this production process.

Melanin acts as a natural filter for solar rays. Consequently, individuals with darker skin pigmentation may require more UVB exposure to produce the same amount of vitamin D as those with lighter skin. Dermatologist Rafael Parisi notes that higher pigmentation tends to result in lower vitamin D production for the same amount of sun exposure. However, experts like nutritionist Fabiano Girade emphasize that blood concentration also depends on age, diet, latitude, season, and supplement use.

Regarding sun protection, while sunscreen can reduce vitamin D production, it rarely blocks it entirely due to inconsistent application. Medical professionals suggest balancing brief, unprotected exposure with regular sunscreen use to mitigate the risks of skin cancer and premature aging. Socioeconomic factors, such as indoor work environments and limited access to nutritious food, also play a role in vitamin D deficiency levels.