Effect of Vitamin D Supplementation During Pregnancy on Blood Concentrations of Toxic Metals (P24-063-19)
Bibliographic record
Abstract
To estimate the dose-response effect of 4200 IU/week, 16,800 IU/week and 28,000 IU/week of vitamin D3 during pregnancy (versus placebo) on maternal delivery whole blood (maternal) and venous cord blood (cord) concentrations of the toxic metals lead (Pb), cadmium (Cd), mercury (Hg), and manganese (Mn) in a randomized clinical trial in Bangladesh. The study included a sub-set of participants (maternal: n = 619; cord: n = 516) from the Maternal Vitamin D for Infant Growth (MDIG) randomized controlled trial in Dhaka, Bangladesh. Vitamin D3 or placebo was administered from 17–24 weeks gestation until delivery. Metal concentrations (maternal and cord) were quantified using inductively coupled plasma mass spectrometry. Metal concentrations in each treatment group were compared to placebo using linear regression. Maternal Cd and Hg and all cord metals were log-transformed due to non-normal distributions, and results were expressed as % differences. Compared to placebo, cord Pb was 8.5% higher in the 4200 IU/week group (CI: −3.6%, 22%; P = 0.18), 16% higher in the 16,800 IU/week group (CI: 3.2%, 30%; P = 0.01) and 11% higher in the 28,000 IU/week group (CI: 0.36%, 23%; P = 0.04). Since 76% of cord Cd samples were below the limit of detection, we dichotomized Cd as detectable or non-detectable. The risk of having detectable Cd was 2.18-fold higher in the 4200 IU/week group (CI:1.27, 3.75; P = 0.005), 1.38-fold higher in the 16,800 IU/week group (CI: 0.76, 2.50; P = 0.29), and 1.72-fold higher in the 28,000 IU/week group (CI:1.02, 2.91; P = 0.04). Prenatal vitamin D3 did not affect maternal metal concentrations, or cord Hg or Mn concentrations. Vitamin D3 increased cord Pb and Cd concentrations without clear dose-response effects. Even at high intake levels, vitamin D3 supplementation in pregnancy was not associated with other cord metal or maternal metal concentrations. Further longitudinal studies are required to explore how vitamin D treatment increases cord metal levels, with little or transient effect on maternal levels, and to describe the trajectory of metal concentrations across gestation in response to vitamin D supplementation. Bill and Melinda Gates Foundation.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 teacher head, 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".