Vitamin D Status Across Age Groups in Turkey: Results of 108,742 Samples from a Single Laboratory

Abstract

Objective:The aim was to determine vitamin D status in the general population in Turkey between 2011 and 2016, and to evaluate the effectiveness of the national vitamin D supplementation programme.Methods:Serum 25-hydroxyvitamin D (25-OHD) measurement data were retrieved from an internationally accredited laboratory, operating nationwide. A total of 108,742 measurements of 25-OHD were analyzed using the cut-off values of 0-11 ng/mL, 12-19 ng/mL, 20-49 ng/mL, 50-70 ng/mL and >70 ng/mL for vitamin D deficiency, insufficiency, sufficiency, possibly harmful and excess respectively.Results:The mean±standard deviation 25-OHD level was 21.6±13.3 ng/mL. Mean 25-OHD concentrations by age groups were: 37.3 ng/mL, 30.1 ng/mL and 23.7 ng/mL for 70 years, respectively.Conclusion:Successful implementation of the national vitamin D supplementation programme, appears to have nearly eliminated vitamin D deficiency for children under 1-years of age. However, the positive impact of the vitamin D supplementation diminishes as children get older suggesting that supplementation may be required in the older children and adults. In addition, improved awareness of the benefits and risks of excess vitamin D should prevent unnecessary and excessive use of vitamin D supplements.

Keywords

• vitamin d
• deficiency
• national prophylaxis program
• 1 year of age