Diseases Affecting the Digestive Tract and the Shade of Skin Color
Like other nutrients, vitamin D present in ingested food is absorbed in the digestive tract. No matter how much vitamin D you consume, if your body fails to absorb it, it’s useless. Certain chronic conditions [5] affecting the digestive tract can cause malabsorption of vitamin D. You may become deficient in vitamin D if this happens.
Celiac disease, Chron’s disease, and cystic fibrosis are common chronic diseases that can interfere with your body’s ability to absorb vitamin D.
Adults with darker skin are at a higher risk of deficiency. This is because people with darker skin make less vitamin D in their skin than people with lighter complexions. Melanin, the pigment that accounts for the color of the skin, is more in dark-skinned people. It limits the production of vitamin D in their skins by 95 to 99 percent. [6]