There's plenty of public awareness about the dangers of skin cancer, but much less about the benefits of sun exposure. Our skin isn't just a passive, inert covering. Taking in sun allows the body to manufacture vitamin D, and more recent research suggests that when exposed to sunlight, skin helps regulate blood pressure. It's possible that current recommendations to stay out of the sun might be counterproductive for darker-skinned people, who are at lower risk for skin cancer and higher risk of hypertension.
In the United States, blacks are much more likely than white, Asian or Hispanic Americans to have hypertension, and they suffer a disproportionate risk of heart disease and strokes. Doctors have examined many potential explanations — stress, diet, genes — and one long overlooked is looking increasingly likely: lack of sun exposure.
Scientists have found that people with higher vitamin D levels have lower blood pressure, but some now think that the vitamin D isn't the main driver of blood pressure, but rather, that sunlight regulates vitamin D and blood pressure through separate mechanisms. In which case, vitamin D supplements won't serve as a complete substitute for sunshine.