Young Red Haired Girl With A Pale Skin On The Sandy Shore

In a number of traditional societies the sun was avoided as much as possible, especially around noon when the ultraviolet radiation in sunlight is at its most intense. Midday was a time when people stayed in the shade and had the main meal followed by a nap.
While dark skin offers better protection from intense ultraviolet light, it may result in low vitamin D levels and has led to concern that darker skinned people living at relatively high latitude, such as African Americans, may have inadequate vitamin D levels. Research shows that dark-skinned people living in Western societies have lower vitamin D levels. The explanation for low vitamin D levels in dark-skinned people is thought to be that melanin in the skin hinders vitamin D synthesis. However, recent studies have found novel evidence that low vitamin D levels among people of African ancestry may be due to other reasons, such as that black women have an increase in serum parathyroid hormone – implicated in adverse cardiovascular outcomes – at a lower vitamin D level than white women. In a large scale association study of the genetic determinants of vitamin D insufficiency in Caucasians no links to pigmentation were found.