Fig 1.
Retinoid disposition during pregnancy.
Retinoids are stored in the liver as retinyl esters and mobilized to peripheral tissues as retinol that is subsequently converted to retinal (by retinol dehydrogenases, RDH) and then to bioactive all-trans-retinoic acid (atRA) and 13-cis-retinoic acid (13cisRA) by aldehyde dehydrogenases. Retinoic acids are converted to oxidative metabolites by cytochrome P450 enzymes including CYP26A1 (liver and embryo/fetus) and CYP26B1 (extrahepatic tissue).
Table 1.
Participant characteristics.
Fig 2.
Longitudinal changes in retinol (A), RBP4 (B), atRA (C), 13cisRA (D), and 4-oxo-13cisRA (E) during pregnancy and postpartum periods. The plots depict the mean (red dots), median (horizontal bars), 25th and 75th quantiles (upper and lower box ranges, respectively), and 1.5 interquartile ranges. The numbers after P and PP indicate the weeks of gestation and the number of weeks passed after delivery, respectively.
Table 2.
Number of participants with retinol plasma concentrations in the vitamin A deficiency (<0.7μM) or insufficiency (0.7–1.05 μM) category.
Fig 3.
Longitudinal changes in the concentrations of albumin (A), albumin-corrected atRA (B), albumin-corrected 13cisRA (C), and the sum of atRA and 13cisRA (D) during pregnancy and postpartum periods. The blue line is from LOWESS (locally weighted scatterplot smoothing) regression, and gray area represents the 95% uncertainty around the smoothed line estimate. P and PP denote pregnancy and postpartum periods, respectively. The numbers after P and PP indicate the weeks of gestation and the number of weeks passed after delivery, respectively.