The most important is the deficiency of vitamins D2 (ergocalciferol) and D3 (cholecalciferol). The basic amount of vitamin D is formed in the skin when light (ultraviolet rays) acts on it, the smaller part comes from food. Vitamin D is fat-soluble, it is contained in small amounts in butter, milk, egg yolk; Especially its high content is noted in the liver and fatty tissue of cod, some other fish and marine animals. In the body is involved in the regulation of calcium and phosphorus metabolism. When there is a lack of food containing vitamin D in the food, as well as an insufficient effect of sun rays on the skin, a clinical picture of the deficiency of this vitamin appears. Additional factors: prematurity of the child, shift of the acid-base state towards acidosis (in particular, with some infectious diseases). The daily requirement of an adult in vitamin D is 100 ME, the child is 500-1000 ME.

Clinical picture. Symptoms in children - see Rickets, in adults - unmotivated weakness, fatigue, demineralization of teeth with rapid progression of caries (especially in pregnant women), osteoporosis, pain in the bones, muscles, paresthesia.

For the diagnosis in adults, the data of biochemical laboratory studies (reduction of inorganic phosphorus in the blood below 30 mg / l, increase in activity of alkaline phosphatase) are of primary importance.

Treatment. Preparations of vitamins D2 and D3 in combination with calcium preparations and ultraviolet irradiation. Further - dispensary observation and repeated courses of treatment (an overdose of vitamin D can cause intoxication). When vitamin D deficiency in adults caused by diseases of the digestive tract and violation of bile secretion, in addition to prescribing vitamin D preparations, the main disease is treated.