Abstract:

Objective: This study was performed to determine the prevalence of vitamin D deficiency and associated factors in apparently-healthy adolescents in the Central Anatolia region of Turkey where nutritional rickets is common. Materials and Methods: This prospective cohort study was performed in the Kirikkale province of Central Anatolia, Turkey. Adolescents aged 1 to 17 years old with no health complaints were enrolled between February 2012 and February 2013. Adolescents younger than 12 and older than 17 age, those with chronic diseases, and those using any medications known to affect vitamin D metabolism were excluded. A total of 358 adolescents, consisting of 235 (65.5%) girls and 123 (34.5%) boys with an average age of 14.6 ± 1.58 years, were included in this study.  Serum concentrations of 25-hydroxy vitamin D [25(OH)D] and other bone mineralization markers were measured in the summer and winter. Results: In blood samples, phosphorus (P), alkaline phosphatase (ALP), bone-ALP (B-ALP), parathyroid hormone (PTH), and 25(OH)D levels were considerably lower in female adolescents than in male adolescents. The rate of vitamin D deficiency was higher in girls than in boys. B-ALP level was compared to Vitamin D level in each season; there was no significant relation in winter, but vitamin D level decreased with increasing B-ALP level in summer. B-ALP level was compared to vitamin D level according to sex; there was no significant relation in male adolescents, but vitamin D level decreased while B-ALP level increased in female adolescents. Conclusion: This study showed that vitamin D deficiency or inadequacy is very common among adolescents, particularly in females in Central Anatolia region of Turkey.

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