My laboratory has been interested in figuring out why the immune system has vitamin D receptors that determine which cells can use vitamin D. In the immune system, vitamin D acts to improve your ability to fight infections and to reduce inflammation. ADADBut those most at risk for low vitamin D levels are people of color and people living at higher latitudes. Dark-skinned individuals are more likely than fair-skinned individuals to be low for vitamin D year-round because the darker skin blocks the UVB rays from producing vitamin D. But even in dark-skinned individuals, vitamin D is lowest in the winter. In the winter, in addition to high vitamin D food, adults should take additional vitamin D from foods or supplements to get at least 600 IU per day of vitamin D. People who have dark skin or avoid sunshine should eat more vitamin D year-round. Vitamin D helps you absorb calcium from your diet, but when vitamin D is too high, calcium levels in the blood go up and that can lead to kidney disease.

Source: Washington Post January 19, 2020 18:56 UTC