[Biomarkers of vitamin status in obese school children].

Inadequate intake of vitamins, noted in children with obesity, reduces the immune system activity, contributes to the metabolic disorders aggravation and may result in comorbidity. The aim of the work was to study sufficiency with vitamins and carotenoids of children with obesity. Material and methods. Examination of vitamin D, B₂, C, A, E and β-carotene status in 50 children (male 36.0%) aged 11-17 years [median (Me) - 14 years] with obesity [Z-score body mass index (BMI) >=2.0, Ме=2.86] by determining serum biomarkers has been conducted. Results and discussion. All of the children had an adequate supply with vitamin C (ascorbic acid level >0.4 mg/dL). Low vitamin A status (retinol <30 μg/dl) was revealed in 8% children. Deficiency of vitamin D [25(OH)D<20 ng/ml], vitamin B₂ (riboflavin <5 ng/ml) and β-carotene (<10 μg/dl) was detected in 62.0, 38.8 and 74.0% of obese children. The percentage of persons with reduced vitamin E serum level (<0.8 mg/dl) was amounted 54.0%. A severe vitamin D deficit (<10 ng/ml) has been detected in 24.0% of children with Z-score BMI >=2.86 (median value) and has not been observed in children with lower body weight, whose serum β-carotene median was 1.5 fold higher (p<0.05). No one was adequately supplied with all 5 studied vitamins and β-carotene. The combined deficiency of 3 or more vitamins took place in 54.0% of obese children. Synchronously suboptimal serum level of ascorbic acid (<50 μmol/l), β-carotene (<0.4 μmol/l) and α-tocopherol/cholesterol ratio (<5.0 μmol/mmol) which is a cardiovascular disease risk factor, has been found in 28.0% of children. BMI was inversely associated with 25(OH)D serum concentration (ρ=-0.313, р=0.027). There was a pronounced negative correlation between serum level of β-carotene and atherogenic LDL cholesterol (ρ=-0.514, p<0.001). Conclusion. The prevalence of combined vitamin D, tocopherol and carotenoids' inadequacy in obese children indicates the importance of vitamin status correction to reduce the risk of metabolic syndrome.