Vitamin D is a micronutrient the human body requires to manage the calcium levels in bones, blood and the digestive system. A few foods, including liver and oily fish, provide vitamin D, but the skin produces most of the required amount, according to the Vitamin D Council.Continue Reading
Most people get enough vitamin D, explains Mayo Clinic. Low levels of the micronutrient cause bones to become thin and brittle. As of 2015, research continues into the role of vitamin D in immune function, insulin resistance and high blood pressure.
Sun exposure provides most of the vitamin D required by the body. Exposing the hands, arms, legs and face to the sun for about 25 percent of the time a sunburn needs to develop provides enough of the vitamin to meet the needs of humans. A person who is deficient in vitamin D is able to make up for 49 days of no sun exposure with six days of casual sun exposure, notes WebMD.
For individuals who remain deficient in vitamin D, options include fortified foods and supplements. Manufacturers fortify dairy products, cereals and juices with vitamin D in the United States, according to WebMD. For people ages 1 to 70, the recommended daily allowance of vitamin D is 600 international units. After age 70, the recommended daily allowance increases to 800 international units. Before age 1, babies need 400 international units.Learn more about Vitamins & Supplements