Maternal 25-hydroxyvitamin D correlates with weight gain and bone metabolism during pregnancy

Background: Vitamin D is involved in the regulation of 3% of the human genome, which encode proteins affecting bone health, immune system and other systems. The status of maternal vitamin D may program neonatal skeletal development. Besides, vitamin D is associated with obesity during pregnancy. Obesity has a detrimental effect on bone metabolism and the level of several hormones related to bone metabolism． Methods: : This cross-sectional study recruited 103 families who visited Anzhen Hospital from January 2017 to June 2017. The age of included pregnant women ranged from 21 to 42 years old. Patients were assigned to different groups according to their body mass index (BMI) and weight gain during pregnancy. The level of 25-hydroxyvitamin D (25-(OH)D) in serum, parathyroid hormone (PTH), total procollagen type 1 N-terminal propeptide (P1NP), osteocalcin (OC), and C-terminal telopeptides type I collagen (CTX) from mothers and neonates were compared. Results: : The results showed that the average level of 25-(OH) D in serum from mothers was 15.09ng/ml during pregnancy and 16.23ng/ml in the umbilical cord. The maternal P1NP increased significantly when the weight gain increased during pregnancy (P<0.01), as well as the fetal weight (P<0.05). Conclusions: : Vitamin D deficiency is prevalent during pregnancy and led to more weight gain during pregnancy, also influence the fetal bone health. Obesity negatively correlates with 25-(OH)D level in serum and has a detrimental effect on bone metabolism.