Effect of Prenatal and Postpartum Vitamin D Supplementation on Circulating Biomarkers of Maternal Bone Metabolism (P24-048-19)
Bibliographic record
Abstract
To estimate the dose-dependent effect of prenatal and postpartum vitamin D supplementation on circulating concentrations of biomarkers of maternal bone formation (osteoprotegerin [OPG], osteocalcin [OC], procollagen type 1 amino-terminal propeptide [P1NP], and OPG/RANKL ratio), bone resorption (receptor activator nuclear factor kappa-β ligand [RANKL], and carboxyterminal telopeptide of type 1 collagen [CTX]), and general markers of bone metabolism (fibroblast growth factor 23 [FGF23]), in a pregnancy cohort in Dhaka, Bangladesh. This study is a sub-study of the Maternal Vitamin D for Infant Growth trial, a randomized controlled trial in which women were enrolled at 17–24 weeks gestation and randomized to one of five weekly oral vitamin D3 supplements or placebo regimens during pregnancy and up to 6 months postpartum: group A (placebo), group B (4200 IU/week), group C (16,800 IU/week), group D (28,000 IU/week), group E (28,000 IU/week during pregnancy and postpartum). Postpartum, all groups other than group E received placebo. Maternal venous blood samples were collected from MDIG participants at enrolment, delivery and 6 months postpartum. Concentrations of FGF23, CTX, and P1NP were determined using ELISAs and OPG, OC, and RANKL concentrations were determined using a Luminex/Millipore magnetic beads kit. For each biomarker (n range, 344 to 606), linear regression was used to compare each treatment group versus the placebo group adjusting for baseline concentrations. For delivery time point analyses, treatment groups D and E (same prenatal vitamin D dose) were combined, while in postpartum analyses the two groups were separated to estimate the postpartum effect. At delivery and 6 months postpartum, there were no significant differences in OPG, OC, OPG/RANKL, RANKL, and FGF23 concentrations between each treatment group versus the placebo group (Table 1 and Table 2). Vitamin D supplementation during the 2ndhalf of pregnancy and up to 6 months postpartum had no effect on markers of bone formation or resorption. Analyses for CTX are underway and will also be presented. Bill and Melinda Gates Foundation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".