Effects of maternal vitamin D status on pregnancy outcomes, health of pregnant women and their offspring.

OBJECTIVE: Pregnancy increases the demand for vitamins, including vitamin D. Data on effects of vitamin D deficiency for pregnant woman and fetus available in Poland are scarce. The aim of this study was to evaluate vitamin D3 concentration in pregnant women and its influence on pregnancy course, health of pregnant women and their offspring.

PATIENTS AND METHODS: The study included 102 healthy pregnant women, aged 21 to 40 years, mean 30.5±4.9 years. Women were divided into three groups based on 25(OH)D serum concentration in the third trimester of pregnancy: Group I - with sufficient 25(OH)D serum concentration (>30 ng/ml), Group II - with vitamin D3 insufficiency (20-30 ng/ml), Group III - with serious vitamin D deficiency (<20 ng/ml).

RESULTS: Optimal vitamin D concentrations were found only in 31.2% of women, however in winter months only in 16%. Bacterial vaginosis was significantly more common in women with vitamin D deficiency and insufficiency (p<0.05). In contrast, there were no relations between vitamin D status and the incidence of gestational diabetes, preeclampsia, mode of delivery and size of newborns. A relationship between vitamin D deficiency and insufficiency during pregnancy and subsequent incidence of respiratory infections in children (p<0.05) was demonstrated.

CONCLUSIONS: 1. The current model of vitamin D supplementation in pregnant women in Poland is insufficient, particularly in winter. 2. Vitamin D deficiency in pregnant women fosters development of bacterial vaginosis during pregnancy and recurrent respiratory infections in children, suggestive of the role of vitamin D in prevention of infections.