OBJECTIVE: Vitamin D deficiency is a global health problem. The aim of this study was to determine the proportion of Czech children with vitamin D deficiency and examine related factors. METHODS: The study subjects were 419 healthy children aged 5 and 9 years. Severe vitamin D deficiency was defined as a serum 25(OH)D level of < 25 nmol/L (3% of children), deficiency as that of 25-50 nmol/L (24% of children), insufficiency as that of 50-75 nmol/L (40% of children) and sufficiency as that of > 75 nmol/L (34% of children). RESULTS: Serum 25(OH)D levels varied mainly with season. The highest levels of 25(OH)D were reached in autumn (median: 79.0 nmol/L), followed by summer (median: 67.8 nmol/L) and winter (median: 56.0 nmol/L). The lowest median value (49.8 nmol/L) was detected in spring. CONCLUSION: Children with sufficiency 25(OH)D levels were more frequently exposed to the sun and exposed a larger part of their body to the sun while spending time outdoors. Levels of 25(OH)D were also associated with using vitamin D supplements within six weeks before sampling.

3rd Faculty of Medicine Charles University Prague Czech Republic

Institute of Endocrinology Prague Czech Republic

National Institute of Public Health Prague Czech Republic

References provided by Crossref.org

High prevalence of low vitamin D status in the Czech Republic: a retrospective study of 119,925 participants