Journal Article

Vitamin D Treatment during Pregnancy and Maternal and Neonatal Cord Blood Metal Concentrations at Delivery: Results of a Randomized Controlled Trial in Bangladesh

Mahmud, Abdullah Al, Roth, Daniel E., Zuchniak, Anna, Qamar, Huma, Ahmed, Tahmeed, Jukic, Anne Marie Z.

2020

Overview

Vitamin D improves absorption of calcium; however, in animal studies vitamin D also increases the absorption of toxic metals, such as lead and cadmium. We examined maternal and neonatal cord blood levels of lead, cadmium, manganese, and mercury after supplementation with vitamin D during pregnancy. The Maternal Vitamin D for Infant Growth trial was a randomized, placebo-controlled, multi-arm study of maternal vitamin D supplementation during pregnancy in Dhaka, Bangladesh (NCT01924013). Women were randomized during their second trimester to blinded weekly doses of placebo or 4,200, 16,800, or 28,000 IU of vitamin D3 throughout pregnancy. Each group had 118-239 maternal blood specimens and 100-201 cord blood samples analyzed. Metals were measured using inductively coupled plasma mass spectrometry. Unadjusted estimates from linear regression models were expressed as percentage differences. Cord blood cadmium was analyzed as detectable or undetectable with log-binomial regression. Maternal cadmium, mercury, and manganese levels were nearly identical across groups. Maternal lead levels were 6.3%, 7.4%, and 6.0% higher in the treatment groups (4,200, 16,800, and 28,000 IU, respectively) vs. placebo; however, 95% confidence intervals (CIs) showed that differences from 4.1% lower to 20% higher were compatible with the data. In treatment groups (4,200, 16,800, 28,000 IU) vs. placebo, neonatal cord blood lead levels were 8.5% (95% CI: , 22), 16% (95% CI: 3.3, 30), and 11% (95% CI: 0.4, 23) higher and had higher risk of detectable cadmium, relative risk (95% CI: 1.3, 3.7), (95% CI: 0.8, 2.5), (95% CI: 1.0, 2.9). Vitamin D supplementation from the second trimester of pregnancy did not influence maternal cadmium, mercury, or manganese levels at delivery. Vitamin D was associated with nonsignificant increases in maternal lead and with significant increases in cord blood lead and cadmium. These associations were not dose dependent. Given that there are no safe levels of metals in infants, the observed increases in cord blood lead and cadmium require further exploration. https://doi.org/10.1289/EHP7265.

• Publisher: National Institute of Environmental Health Sciences,Environmental Health Perspectives
• Subject: Absorption / Bangladesh / Biocompatibility / Biomarkers / Birth weight / Blood / Blood levels / Cadmium / Calciferol / Calcium - metabolism / Calcium absorption / Cholecalciferol - adverse effects / Cholecalciferol - therapeutic use / Confidence intervals / Cord blood / Dietary supplements / Dietary Supplements - adverse effects / Disease control / Environmental Pollutants - blood / Female / Fetal Blood - metabolism / Gestational age / Heavy metals / Humans / Inductively coupled plasma mass spectrometry / Infant / Infant, Newborn / Infants / Lead / Lead - blood / Manganese / Mass spectrometry / Mass spectroscopy / Medical laboratories / Mercury / Mercury (metal) / Metal concentrations / Neonates / Newborn babies / Placebos / Pregnancy / Pregnancy Trimester, Third / Regression analysis / Regression models / Research ethics / Statistical analysis / Supplements / Ultrasonic imaging / Vitamin D / Vitamin D - adverse effects / Vitamin D - therapeutic use / Vitamin D3 / Womens health