Endocrine Abstracts

Vitamin D deficiency has been recognized as a common public health issue in many countries, however its prevalence and impact on calcium metabolism parameters has not been extensively studied in Poland yet.

The aim of the study was to assess the vitamin D status in sample of Polish urban population.

Material and methods: Study included 273 healthy volunteers (76 males, 197 females, median age 58 years) living in city Krakow in south-eastern part of Poland. 56% of them were examined during the late autumn–winter, the rest during spring–summer of 2011–2012. In each subject plasma level of vitamin 25(OH)D₃, PTH, total calcium, phosphate, alkaline phosphatase (AP), as well as urinary calcium concentration were assessed. The demographic data and dietary daily calcium intake questionnaire were also obtained.

Results: Median vitamin D level was 21.2 ng/ml (range 3.0–55.4 ng/ml). Mild vitamin D deficiency (<50 ng/ml) was noted in 98.9%, severe deficiency in 81% of studied population. The vitamin D level was statistically lower in winter than in summer (median value of 19.6 vs 23.5 ng/ml, P=0.0002; 88.2 vs 71.7% of subjects). There was statistically significant correlation between vitamin D and PTH levels (r=−0.21, 95% CI: −0.27 to −0.09, P=0.0004) and urinary calcium concentration (r=0.15, 95% CI: 0.02 to 0.27, P=0.02). Correlation between vitamin D and AP almost met statistical significance (r=−0.12; 95% CI: −0.23 to +0.007; P=0.058). There was no significant relationship between vitamin D and plasma calcium and phosphate levels. There was no seasonal variation in plasma PTH and calcium levels.

Conclusions: Vitamin D deficiency in Polish adult population is very frequent even during the summer. Vitamin D level in vitamin D deficient population is an important determinant of PTH level.