Vitamin D, including all its vitamers, being a food substance, does not belong to drugs, it can specifically cure those diseases that were caused by its deficiency in the diet. Vitamin D may be officially registered as a dietary supplement or medicine. In both cases, it is intended for the prevention of vitamin D deficiency as well as for the treatment of profound deficiency and its consequences. Doses of vitamin D in them are strictly regulated; they are strictly controlled before being imported and placed on the market. In relation to monovitamins and vitamin complexes registered as dietary supplements, especially for children, increased requirements are imposed on the doses of micronutrients, their forms, auxiliary components Due to the high doses of micronutrients they contain, the presence of auxiliary components that are not permitted for use in baby food, many monovitamins and vitamin complexes simply cannot be registered as dietary supplements and, as a result, are registered as medicines. However, this does not mean that they are more effective. Food supplements in their composition are closer to food products, which confirms the validity of their assignment to the category of specialized products. The effectiveness of vitamin D depends not on the form of state registration, but on the dose, its form and the initial supply of the organism. In order to prevent alimentary deficiency of vitamin D, it is advisable to use dietary supplements, the doses in which are close to the physiological need.