Vitamin D deficiency during winter months among an adult, predominantly urban, population in northern Poland

Abstract

Introduction: Vitamin D is vital in the regulation of the calcium-phosphate metabolism, has a direct impact on the musculoskeletal system, and also affects numerous other systems. Widespread vitamin D deficiency and its detrimental effect on health have been reported globally. Data concerning vitamin D status in Polish adult population is scarce.

Material and methods: Ambulatory patients of an outpatient clinic in Gdańsk were included in the study. Serum concentrations of 25(OH) D, parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium and phosphorus were determined. In a questionnaire declared UVB exposure, dietary vitamin D and calcium intake, and health status of the subjects were assessed. Non- and parametric tests, logistic regression and population attributable risk were applied in data analysis.

Results: 448 adults were examined from February to mid-April 2012, 305 women and 143 men, aged 19 to 86 (mean 46.3 ± 14.9 years). Mean 25-hydroxyvitamin D concentration was 14.3 ± 6.6 ng/mL. 84.4% of subjects were vitamin D deficient (25(OH)D < 20 ng/mL); 13.2% presented insufficient (20–30 ng/mL), and 2.5% (or 11 subjects) sufficient 25(OH)D concentrations. Significantly higher 25(OH)D concentrations were found in subjects who reported more UVB exposure, supplemented vitamin D orally and those who declared more physical activity. 21% of subjects had elevated serum PTH concentration (i.e. > 62 pg/mL); mean parathormone was 48.6 ± 25.2 pg/mL. A linear correlation was found between the logarithm of PTH and logarithm of 25(OH)D concentrations (r = –0.21, p < 0.001).

Conclusions: Results obtained here demonstrate the necessity of implementing a monitoring and prophylaxis programme of vitamin D deficiency in Poland. (Endokrynol Pol 2014; 65 (2): 105–113)