How Your Body Uses Vitamin D
Vitamin D is a fat-soluble vitamin that promotes absorption of calcium and phosphorus. Most people associate the nutrient calcium with healthy bones and teeth, but no matter how much calcium you have in your diet, without vitamin D, your body can’t absorb and use the mineral. So vitamin D is vital for building — and holding — strong bones and teeth.
Researchers at the Bone Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston say vitamin D may also reduce the risk of tooth loss by preventing the inflammatory response that leads to periodontal disease, a condition that destroys the thin tissue (ligaments) that connects the teeth to the surrounding jawbone.
A report in the February 2006 issue of The American Journal of Public Health suggests that taking 1,000 international units (IU) of vitamin D a day may cut in half a person’s risk of developing some forms of cancer, including cancer of the colon, breast, or ovaries.
Vitamin D comes in three forms: calciferol, cholecalciferol, and ergocalciferol. Calciferol occurs naturally in fish oils and egg yolk. In the United States, it’s added to margarines and milk.
Cholecalciferol is created when sunlight hits your skin and ultraviolet rays react with steroid chemicals in body fat just underneath. Ergocalciferol is synthesized in plants exposed to sunlight. Cholecalciferol and ergocalciferol justify vitamin D’s nickname: the Sunshine Vitamin.
The RDA for vitamin D is measured either in International Units (IUs) or micrograms (mcg) of cholecalciferol: 10 mcg cholecalciferol = 400 IU vitamin D.