96. Blood metals and vitamin D status in a pregnancy cohort: A bidirectional biomarker analysis (lay summary)

Fisher M, Potter B, Little J, Oulhote Y, Weiler HA, Fraser WD, Morisset AS, Braun JM, Ashley-Martin J, Borghese, MM, Shutt R, Kumarathasan P, Lanphear BP, Walker M, Arbuckle TE. Environmental Research 2022 Feb 28:113034. doi: 10.1016/j.envres.2022.113034

Studies have shown that higher levels of metals such as cadmium and lead are associated with lower vitamin D status.  However, other research proposes that higher vitamin D status can help lower blood metals.  This puts into question the direction of the association; what is causing what?

Using data form the Maternal-Infant Research on Environmental Chemicals (MIREC) study, this study used three different methods to investigate the association of cadmium and leaed blood biomarkers with vitamin D status (25-hydroxyvitamin D or 25OHD) in pregnant women.

Results showed that most women (~85%) had 25OHD levels >50 nmol/L; a level suggested to be adequate for bone and overall health.  Although initial analysis showed some evidence that increasing levels of metals may be associated with lower 25OHD concentrations, the bidirectional analysis, a type of analysis that controls for reverse causation, suggested that higher early pregnancy vitamin D status may lower cadmium and lead later in pregnancy.

These results suggest that there is a possible modifying effect of vitamin D on metal levels in pregnant women.