For citations:

Volkov M.M., Rafrafi H., Smirnov A.V. SIGNIFICANCE OF SEASONAL FACTOR IN EVALUATION OF VITAMIN D STATUS AT PATIENTS WITH EARLY STAGES OF CHRONIC KIDNEY DISEASE. Nephrology (Saint-Petersburg). 2012;16(2):79-83. (In Russ.) https://doi.org/10.24884/1561-6274-2012-16-2-79-83