To date, the most discussed issue is the rational dosage and duration of cholecalciferol preparations course for the correction and prevention of hypovitaminosis D. Objective of the research: to compare the structure of provision and the median 25 (OH) D before (2013–2016) and during the introduction into clinical practice (2018–2019) of the National Program Vitamin D Deficiency in Children and Adolescents in the Russian Federation: Modern approaches to correction» in young children. Materials and methods: the study had two stages. The first stage took place as a part of the RODNICHOK2 study from 2013 to 2016 before the implementation of the National Program «Vitamin D Deficiency in Children and Adolescents in the Russian Federation: Modern Approaches to Correction». The second stage of the study took place in 2018–2019 during the implementation of the National Program in clinical practice. The study participants were 246 children aged from 1 month to 3 years who took cholecalciferol preparations. The assessment of calcidiol concentration in the blood serum was assessed by the method of chemiluminescence immunoassay (CLIA) using reagents Liaison® 25OH Vitamin D Total Assay on the Liaison Dia Sorin Pleutschland GmbH device in the centralized laboratory of Scientific Center EFIS Ltd, Moscow. Results: during the introduction into clinical practice of the National Program, the frequency of prescribing a dosage of 500 IU/day significantly decreased to 4,9% (χ2=80,4, p<0,001), 1000 IU/day – statistically significantly increased to 71% (χ2=53,5; p<0,001), and a dose of 1500 IU/day was taken by 24% of children, mainly in the second and third years of life. In children examined in 2013–2016, the median serum calcidiol was 29,1 [22,8; 39,5] ng/ml, statistically significantly lower than in 2018– 2019, – 51,3 [38,1; 61,5] ng/ml (p<0,001). Hypovitaminosis D in young children in southern Russia until 2018 was diagnosed in 54,9%, statistically significantly more often than during the implementation of the National Program – in 12.2% of children (χ2=24,3, p<0,001). The number of children with a calcidiol level of more than 30 ng/ml, on the contrary, statistically significantly increased from 45,1 to 87,8% (χ2=39,9, p<0,001). There was a statistically significant decrease in the number of children with vitamin D deficiency – only 10 (12,2%) cases, while earlier their number was 62 (37,8%) (χ2=17,3, p<0,001). Among children examined in 2018–2019, it was possible to completely eliminate severe deficiency (calcidiol level less than 10 ng/ml) and vitamin D deficiency (10–20 ng/ml), while previously it was revealed in 6 (3,7%) (χ2=220,8, p<0,001) and 22 (13,4%) children (χ2=167,9, p<0,001). In 2013–2016 the indicator of the recommended average daily dosage of vitamin D was 73,3 [51,6; 103,1] IU/kg per day, while in 2018–2019. During the implementation of the recommendations set out in the National Program – 125,0 [102,0; 148,7] IU/kg per day (p<0,0001). Conclusion: the study confirmed daily doses per kilogram of body weight in the range from 100 to 150 IU/kg, included in the main provisions of the recommendations for prophylactic intake of vitamin D preparations at an early age. The introduction of the recommendations on the prophylactic course of vitamin D supplementation described in the National Program «Vitamin D Deficiency in Children and Adolescents in the Russian Federation: Modern Approaches to Correction» into wide clinical practice allowed to achieve a significant increase in the number of children receiving additional vitamin D supplements. The recommended average daily dose in comparison with the period before the implementation of the National Program has increased statistically significantly.
Prevalence of vitamin D deficiency in various regions of the Russian Federation: results of the first stage of the multicenter cross-sectional randomized study
