Hypovitaminosis D in children, adolescents, and adults in the Irkutsk region: who is at risk?

Background. Vitamin D deficiency and insufficiency are highly prevalent worldwide, affecting a significant proportion of the general population. This issue is of particular concern in Eastern Siberia due to its geographical location and climate.

Objective. To assess vitamin D status among the population of the Irkutsk region with consideration of seasonal, sex-based, and age-related differences, in order to identify high-risk groups for hypovitaminosis D.

Materials and methods. A retrospective, non-controlled, selective study was conducted to assess the prevalence of vitamin D deficiency among 939 patients: 148 children in clinic of the Scientific Center for Family Health and Human Reproduction Problems, and 791 adults recruited at the Center for Innovative Medicine in 2023-2024. Vitamin D concentrations were determined using ELISA 25-OH vitamin D test systems (Euroimmun AG, Germany).

Results. Age-specific differences in serum 25-hydroxyvitamin D [25(OH)D] concentrations were observed. Among children, the highest levels were observed in preschoolers and younger school-age children (32.8 ± 17.5 ng/mL). A decline in vitamin D levels was noted during adolescence: in the 12-14-year age group, the mean was 27.3 ± 13.9 ng/mL; in older adolescents (15-17 years), the lowest levels were detected - 21.1 ± 11.7 ng/mL. Among adults, 25(OH)D levels demonstrated an increasing trend with age. In young adults (18-44 years), the mean concentration was 31.5 ± 17.2 ng/mL; in middle-aged adults (45-59 years) - 33.7 ± 18.8 ng/mL; and in older adults (> 60 years), the highest mean value was recorded at 41.2 ± 23.6 ng/mL.

Conclusion. Seasonal analysis revealed statistically significant differences in 25(OH)D levels between the autumn - winter and spring - summer periods (p = 0.0005).

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