Vitamin D supplementation in winter – for whom, what doses and how often? Review article

Abstract

The majority of the natural vitamin D in humans is synthesized in the skin exposed to ultraviolet radiation. Due to the widespread vitamin D deficiency in the world, including Poland, oral supplementation is recommended, particularly in winter. In the general population, cholecalciferol is used to prevent and treat vitamin D deficiencies. Depending on the patient’s preferences, daily doses, once a week or twice a month are recommended. In order to maintain better compliance of once a week doses, e.g. 20,000 IU, are increasingly preferred. The primary benefits of prophylaxis and treatment of vitamin D deficiency have been shown for the musculoskeletal system. However, in recent years, papers have been published on the role of vitamin D in autoimmune diseases, diabetes, cardiovascular diseases and depression. The guidelines that apply in Poland contain among others, the recommendation of vitamin D supplementation, especially in the autumn and winter period, and as well as in the spring and summer period, if exposure to ultrafiolet radiation is insufficient. Vitamin D supplementation is generally safe, although it is unclear how high doses cause toxic effects. Adverse effects may occur in children, granulomatous diseases, primary hyperparathyroidism or idiopathic childhood hypercalcemia. In these groups, calcium and phosphate metabolism should be closely monitored.