Selected Questions and Answers on Vitamin D
Joint FAQs of BfR, DGE and MRI, 22 October 2012
Vitamin D promotes the intake of calcium from the gastrointestinal tract as well as the hardening of the bone. It influences muscle power, regulates the calcium and phosphate metabolism and is also involved in other metabolic processes ofthe body. Vitamin D is formed in human skin under the influence of sunlight. In contrast to the quantity the body produces itself, vitamin D intake via food only accounts for a relatively low percentage of the vitamin D supply. The German Nutrition Society (DGE, Deutsche Gesellschaft für Ernährung e. V.) estimates 20 micrograms of vitamin D per day to be an appropriate intake for children, teenagers and adults if the body does not produce any by itself. (http://www.dge.de/pdf/ws/Referenzwerte-2012-Vitamin-D.pdf)
General enrichment of foods with vitamin D is not recommended. The focus is on the body’s own production of vitamin D, hence the recommendation is to produce and store vitamin D by means of exposing the skin to sunlight. The amount the body produces itself varies from person to person and depends on other factors, such as latitude and time of the year. It is recommended to expose the body to the sun for a total of approx. 5 to 25 minutes per day with face, hands and large parts of arms and legs uncovered. The intake of vitamin D preparations is only recommended if a targeted improvement of the supply, especially concering the supply of risk groups, cannot be achieved by diet or exposure to sunlight.
BfR, DGE and MRI have summarised some frequently asked questions and answers on vitamin D below.