This article is more than 5 years old. Information may no longer be current.
Serum 25-(OH)D thresholds for PTH suppression similar during pregnancy, postpartum
During pregnancy and postpartum, the shape of the relationship between serum 25-hydroxyvitamin D and parathyroid hormone differs, according to study findings. However, the 25-hydroxyvitamin D thresholds for parathyroid hormone suppression are similar.
Ravi Retnakaran, MD, MSc, FRCP, an endocrinologist at the Leadership Sinai Center for Diabetes at Mount Sinai Hospital in Toronto, and colleagues evaluated 468 women in late pregnancy and at 3 and 12 months postpartum for 25-(OH)D and parathyroid hormone (PTH) to determine the relationship between the two during and after pregnancy.
Inverse relationships were found between 25-(OH)D and PTH during pregnancy, 3 months postpartum and 12 months postpartum (P < .0001 for all).
A linear relationship between 25-(OH)D and PTH up to a 25-(OH)D threshold of 82 nmol/L is the optimal model during pregnancy. After pregnancy, curvilinear relationships were found between 25-(OH)D and PTH up to the threshold when PTH is suppressed.
No differences were found during pregnancy, 3 months postpartum and 12 months postpartum for the 25-(OH)D thresholds associated with PTH suppression (all P .26).
“The shape of the relationship between 25-(OH)D and PTH differs between pregnancy and the postpartum,” the researchers wrote. “Specifically, when serum 25-(OH)D is below the threshold at which PTH is suppressed, the relationship is linear in pregnancy but curvilinear in the postpartum. Importantly, however, the 25-(OH)D thresholds associated with PTH suppression are similar between pregnancy (82 nmol/L), 3-months postpartum (71 nmol/L), and 12-months postpartum (81 nmol/L). While these data suggest similar thresholds for vitamin D sufficiency at all three points in time, the limited achievement of these targets offers support for the emerging concept that greater antenatal vitamin D supplementation warrants evaluation in clinical trials.” – by Amber Cox
Disclosure: The researchers report no relevant financial disclosures.