For citations:

Avdeeva V.A., Suplotova L.A., Pigarova E.A., Rozhinskaya L.Y., Troshina E.A. Vitamin D deficiency in Russia: the first results of a registered, non-interventional study of the frequency of vitamin D deficiency and insufficiency in various geographic regions of the country. Problems of Endocrinology. 2021;67(2):84-92. (In Russ.) https://doi.org/10.14341/probl12736