Vitamin D is needed for normal absorption of calcium and phosphorus. It helps put these minerals into bones and teeth. This makes bones stronger and reduces risk for bone fractures. Vitamin D also helps keep the immune system functioning normally, so our bodies can resist some types of disease. This 3-page fact sheet is a major revision that discusses effects of vitamin D deficiency, intake recommendations, and sources of vitamin D. Written by Linda B. Bobroff and Isabel Valentín-Oquendo, and published by the UF/IFAS Department of Family, Youth and Community Sciences, revised November 2017.
http://edis.ifas.ufl.edu/fy207