Determinants of maternal vitaminD concentrations in Slovenia : Aprospective observational study.

Abstract

To analyze the vitaminD status of pregnant women in Slovenia and the factors influencing it. The study was performed in Maribor University Medical Centre (location 46°N). Maternal serum 25-hydroxy-vitaminD (25(OH)D) in 4 groups of 100 pregnant women in 4 different seasons of the year was measured at the time of delivery. Data on life style, eating habits, sunbathing and intake of vitaminD supplements during pregnancy were obtained using aquestionnaire. Information on maternal outcome was acquired from medical records. Duration of sunlight and average temperature in the month preceding delivery were calculated from meteorological data. The average maternal 25(OH)D concentration ranged from 28.5± 17.1 nmol/l in March to 54.8± 24.1 nmol/l in June (p< 0.001). Severe vitaminD deficiency, i.e. <25 nmol/l 25(OH)D was present in 23.6% of women overall. In multiple regression analysis supplements containing vitaminD (β= 0.225, p< 0.001) and duration of intentional exposure to sunlight (β= 0.192, p= 0.026) were associated with maternal 25(OH)D status. Significantly lower vitaminD levels were observed in women who had a cesarean section (t= 2.053, p= 0.041) and those with premature delivery (t= 2.296, p= 0.022). VitaminD levels were not associated with the occurrence of gestational diabetes, gestational hypertension or infections during pregnancy. Ahigh prevalence of vitaminD deficiency was detected at the end of pregnancy, especially in the months following autumn and winter and in women who did not take supplements containing vitaminD.