Analysis of vitamin D sufficiency of young children in the south of Russia and in Saudi Arabia

Aim. The purpose of this work was to analyze the vitamin D sufficiency in children of the first three years of life, living in southern Russia and in the north-west of the Kingdom of Saudi Arabia during the period of minimal insolation. Materials and methods. In the period from October to March, 132 children from the Tabuk city of the Kingdom of Saudi Arabia (28°23'50 " N 36°34'44" E) and 262 patients living in Stavropol of Russian Federation (45°02' N 41°58' E) were examined. The assessment of vitamin D availability was based on the determination of serum calcidiol [25(OH)D] by competitive chemiluminescent immunoassay. Results. The level of calcidiol [Me (Q25-Q75)] of children in Tabuk was 28.0 (21.9-35.9) ng/ml, in Stavropol - 23.7 (16.2-32.7) ng/ml (p=0.0003). Vitamin D deficiency was detected in 26 (19.7%) children from Saudi Arabia and 97 (37.0%) from Stavropol (p<0.02), insufficiency (from 21 to 29 ng/ml) in 42 (31.8%) and in 87 (33.2%) cases, and normal provision in 64 (48.5%) and 78 (29.8%) children, respectively (p<0,0005). The availability of cholecalciferol in children from 1 to 5 months was 24.2 (18.7-31.9) ng/ml in Tabuk and 25.3 (14.8-34.1) ng/ml in Stavropol, patients from 6 to 12 months - 34.3 (27.4-37.8) ng/ml and 31.9 (22.1-39.9) ng/ml, children from 12 to 24 months - 31.7 (25.1-41.6) ng/ml and 22.9 (15.8-28.8) ng/ml (p=0.0002), patients from 2 to 3 years old -24.1 (19.5-30.3) ng/ml and 18.2 (14.2-24.8) ng/ml in Tabuk and Stavropol, respectively (p=0.0003). The availability of cholecalciferol in children not receiving vitamin D preparations in Tabuk was 27.8 (21.0-34.6) ng/ml, in Stavropol 19.4 (12.7-25.5) ng/ml (p=0.0003). Against the background of prophylactic intake of vitamin D preparations, the level of calcidiol in children in Tabuk was 32.9 (26.1-34.3) ng/ml, and without taking - 27.8 (21.0-34.6) ng/ml (p=0.05); in Stavropol - 29.0 (21.6-39.4) ng/ml against the background of taking and 19.4 (12.7-25.6) ng/ml without it (p=0.000000001). Vitamin D deficiency was detected in 13 (24.1%) patients of Tabuk without taking, and against the background of pharmacological prophylaxis there was not a single child with a level of 25(OH)D below 20 ng/ml. Stavropol children without taking cholecalciferol preparations had a vitamin D deficiency in 70 (52.6%) cases and in 27 (20.9%) against a background of taking it (p<0.0005). Conclusion. Vitamin D provision for children in the first three years of life living in the south of the Russian Federation was significantly worse than in a similar age cohort of children from the north-west of the Kingdom of Saudi Arabia. The age trends in vitamin D provision were the same for Saudi and Russian children; in the first year of life, a large proportion of patients in southern Russia maintain vitamin D status commensurate with Arabian, in the second and third years of life, vitamin D availability decreases in both countries, but in Russia Vitamin D deficiency is more common. The level of natural insolation in Tabuk allows maintaining the number of children with vitamin D deficiency at about 20%, while in the south of Russia, without drugs prophylaxis of hypovitaminosis D, more than half of children have vitamin D deficiency.

vitamin D, vitamin D deficiency, cholecalciferol, prevention of hypovitaminosis D, insolation