Maternal vitamin D biomarkers are associated with maternal and fetal bone turnover among pregnant women consuming controlled amounts of vitamin D, calcium, and phosphorus1,2

• Published in: Bone (New York, N.Y.) N.Y.), 2016-12, Vol.95, p.183-191
• Main Authors: Park, Heyjun, Brannon, Patsy M., West, Allyson A., Yan, Jian, Jiang, Xinyin, Perry, Cydne A., Malysheva, Olga, Mehta, Saurabh, Caudill, Marie A.
• Format: Article
• Language: English
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2016.12.002

Vitamin D plays a central role in calcium homeostasis; however, its relationship with bone turnover during pregnancy remains unclear due to a lack of studies that have rigorously controlled for other nutrients known to influence bone metabolism. Similarly, prior investigations of the effect of pregnancy on bone turnover relative to the nonpregnant state may have been confounded by varying intakes of these nutrients. Nested within a controlled intake study, the present investigation sought to quantify associations between maternal vitamin D biomarkers and biochemical markers of bone turnover among pregnant (versus nonpregnant) women and their fetuses under conditions of equivalent and adequate intakes of vitamin D and related nutrients. Changes in markers of bone turnover across the third trimester were also examined. Healthy pregnant (26–29 wk gestation; n=26) and nonpregnant (n=21) women consumed 511IU vitamin D/d, 1.6g calcium/d, and 1.9g phosphorus/d for 10 weeks while participating in a controlled feeding study featuring two choline doses. Based on linear mixed models adjusted for influential covariates (e.g., BMI, ethnicity, and season), pregnant women had 50–150% higher ( P