Vitamin D status in Poland.

INTRODUCTION    Epidemiological data on vitamin D status in the Polish population are limited. OBJECTIVES    The aim of the study was to evaluate the vitamin D status in a representative group of adult inhabitants of 22 Polish cities, based on the analysis of serum 25-hydroxyvitamin D [25(OH)D] levels. PATIENTS AND METHODS    This cross-sectional study included a total of 5775 adult volunteers (4464 women; 1311 men; mean age, 54.0 ±15.9 years; range, 15.6-89.8 years), who were enrolled and examined through late winter and spring 2014. Serum concentrations of 25(OH)D were determined using the Liaison XL system (DiaSorin; CLIA method). Demographic and anthropometric data were also analyzed. RESULTS    The mean 25(OH)D concentration in the studied population was 18.0 ±9.6 ng/ml; 65.8% of the patients had 25(OH)D levels of less than 20 ng/ml; 24.1% had suboptimal levels of 20 to 30 ng/ml; and only 9.1% demonstrated the optimal levels of 30 to 50 ng/ml. In 89.9% of the studied population, 25(OH)D levels of less than 30 ng/ml were found. Obesity, defined as body mass index (BMI) over 30 kg/m2, was associated with lower 25(OH)D levels compared with normal weight (15.8 ±8.5 vs 18.5 ±9.7 ng/ml; P <0.0001). Lower 25(OH)D levels were observed in men, younger individuals, and individuals with excess body weight and higher BMI. CONCLUSIONS    The results of our study, which involved the most representative sample size of Polish adults, support the previously reported data on vitamin D status. The levels of 25(OH)D determined for adults in our study demonstrate that the majority of the Polish population is vitamin D deficient, at least during winter and spring, and that preventive or interventional strategies must be considered to improve the vitamin D status in Poland.