where is vitamin d synthesized in the skin
Vitamin D The skin consists of two primary layers: the inner layer called the dermis, composed largely of connective tissue, and the outer, thinner epidermis.[162] Thick epidermis in the soles and palms consists of five strata; from outer to inner, they are: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Vitamin D is produced in the keratinocytes[163] of two innermost strata, the stratum basale and stratum spinosum.[160]
Sun tanning Moderate exposure to the sun contributes to the production of melanin and vitamin D by the body, but excessive exposure to ultraviolet rays has negative health effects, including sunburn and increased risk of skin cancer,[1] as well as depressed immune system function and accelerated aging of the skin. Some people tan or sunburn more easily than others. This may be the result of different skin types and natural skin color, and these may be a result of genetics.