The level of vitamin D and parameters of calcium and phosphorus metabolism in primary school children living in the south of Bashkortostan

Aim. Estimation of vitamin D level and calcium-phosphorus metabolism in urban and rural school children of 8-9 years old, living in the south of Bashkortostan. Methods. The study included two groups of 2-3 class pupils: 87 children living in Meleuz and 93 children of Meleuz Region (Zirgan village). The average age was 8.3±0.66 years. The following parameters were analyzed: serum levels of 25-hydroxyvitamin D, phosphorus, total calcium level, urine calcium level, and daily calcium intake. Results. 72.4% of children from Meleuz and 30.1% of rural children had vitamin D deficiency, subclinical vitamin D-deficiency was detected in 27.6 and 63% of primary school children, respectively. The average serum calcium level in schoolchildren living in town was somewhat lower than in rural residents (p=0.0012), and was close to the lower limit of the reference values. Serum phosphorus levels and urine calcium levels were within the physiological range in the examined children no matter of where they lived. The leading causes of calcium-phosphorus metabolism alterations are reduced calcium intake and vitamin D deficiency. Conclusion. The vast majority of primary school children on the south of Bashkortostan had vitamin D-deficiency or subclinical vitamin D-deficiency. Dietary calcium intake is 60 to 70% of the age norm, which is characterized as a moderate deficit.