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Vitamin D Concentration in Maternal and Umbilical Cord Blood by Season
Regina Wierzejska1, Mirosław Jarosz2, Włodzimierz Sawicki3
1Department of Nutrition and Dietetics, Clinic of Metabolic Diseases and Gastroenterology, Institute of Food and Nutrition, 02-903 Warsaw, Poland. rwierzejska@izz.waw.pl.
Summer is generally considered to be the season when the body is well-supplied with vitamin D. The aim of this study was to compare maternal and umbilical cord blood concentrations of vitamin D during two extreme seasons of the year in Poland-winter and summer. A total of 100 pregnant women with no history of chronic diseases before pregnancy were included in the study. Pre-delivery maternal venous blood and neonatal cord blood samples were collected and total 25(OH)D concentration was measured. Data on vitamin D consumption (collected with the use of Food Frequency Questionnaire) and lifestyle factors were taken. Both, maternal and umbilical cord blood concentrations of vitamin D were higher in the summer group as compared to the winter group (mean 22.2 ± 6.5 ng/mL vs. 16.5 ± 8.2 ng/mL (p < 0.001), respectively for the mothers and 31.3 ± 9.4 ng/mL vs. 22.7 ± 11.0 ng/mL (p < 0.0001), respectively for the neonates). However, only 16% of the pregnant women reached the optimal vitamin D concentration during summer. Therefore, summer improves the levels of vitamin D in the body but does not guarantee the recommended concentration and supplementation throughout the whole year is essential.
Summer is generally considered to be the season when the body is well-supplied with vitamin D. The aim of this study was to compare maternal and umbilical cord blood concentrations of vitamin D during two extreme seasons of the year in Poland-winter and summer. A total of 100 pregnant women with no history of chronic diseases before pregnancy were included in the study. Pre-delivery maternal venous blood and neonatal cord blood samples were collected and total 25(OH)D concentration was measured. Data on vitamin D consumption (collected with the use of Food Frequency Questionnaire) and lifestyle factors were taken. Both, maternal and umbilical cord blood concentrations of vitamin D were higher in the summer group as compared to the winter group (mean 22.2 ± 6.5 ng/mL vs. 16.5 ± 8.2 ng/mL (p < 0.001), respectively for the mothers and 31.3 ± 9.4 ng/mL vs. 22.7 ± 11.0 ng/mL (p < 0.0001), respectively for the neonates). However, only 16% of the pregnant women reached the optimal vitamin D concentration during summer. Therefore, summer improves the levels of vitamin D in the body but does not guarantee the recommended concentration and supplementation throughout the whole year is essential.
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