Vitamin D status during pregnancy and in cord blood in a large prospective French cohort

Background & aims: Vitamin D status during pregnancy and in newborns has never been studied in France. This study aims at determining the vitamin D status during the first and third trimesters of pregnancy (T1, T3) and in cord blood (CB) in the middle-north of France. Methods: We conducted a prospective cohort study in five French centers (latitude 47.22 to 48.86 degrees N). Serum 25(OH)-vitamin D (25(OH)D) concentrations were measured using a radioimmunoassay during T1,T3 and in CB. According to the French guidelines, pregnant women received cholecalciferol,100,000 IU, in the seventh month. Results: Between April 2012 and July 2014, 2832 women were included, of whom 2803 were analyzed (mean +/- SD age: 31.5 +/- 5.0 years; phototypes 5-6: 21.8%). Three and 88.6% of participants received supplementation during the month before inclusion and in the seventh month, respectively. At T1, 13, and CB, mean 25(OH)D concentrations were 21.9 +/- 10.4, 31.8 +/- 11.5, and 17.0 +/- 7.2 ng/mL, respectively, and 25(OH)D was <20 ng/mL in 46.5%,14.0%, and 68.5%, respectively. At T1, body mass index >= 25 kg/m(2), dark phototypes, sampling outside summer, and no supplementation before inclusion were independently associated with vitamin D insufficiency (25(OH)D < 20 ng/mL). Women who received cholecalciferol supplementation in month 7 had higher 25(OH)D at T3 than non-supplemented women (32.5 +/- 11.4 versus 25.8 +/- 11.4 ng/mL, p = <0.001) and marginally higher 25(OH)D in CB (17.2 +/- 7.2 versus 15.5 +/- 7.1 ng/mL, p = 0.004). Conclusions: Despite the recommended supplementation, vitamin D insufficiency is frequent during pregnancy and in newborns in France. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.