Age, Sex, and Seasonal Variations in the Serum Vitamin D3 Levels in a Local Turkish Population

Results: A large percentage of the adult Turkish population has insufficient levels of vit D during the winter and summer. Serum 25-(OH)D levels were significantly lower in the winter compared with the summer season (mean vit D: 13.9 µ/l and 19.7 µ/l, respectively; p≤0.001). The prevalence of 25-(OH)D deficiency was 94% in the winter and 85% in the summer. With respect to age or sex, there were no differences in the 25-(OH)D levels. Conclusion: Our results indicate that although Turkey is a Mediterranean country, the Turkish people should check have their levels of 25-(OH)D periodically checked, and if necessary, appropriate supplements should be given to prevent a secondary chronic disease due to vit D deficiency.