Cornell University, Division of Nutritional Sciences, Ithaca, NY.
J Nutr. 2012 Jan;142(1):33-9. doi: 10.3945/jn.111.145961. Epub 2011 Nov 23.
The determinants of placental transport of dietary iron remain largely uncharacterized. The objective of this research was to elucidate determinants of fetal Fe transfer from maternally ingested dietary heme and non-heme Fe. The study was undertaken in 19 pregnant females (16-32 y) who ingested intrinsically labeled (58)Fe-heme and a nonheme Fe source ((57)FeSO(4)) during the third trimester of pregnancy. At delivery, maternal and cord blood was obtained to assess neonatal (57)Fe and (58)Fe enrichment as a function of maternal/neonatal Fe status [serum ferritin (SF), transferrin receptor, hemoglobin (Hb), total body Fe, and hepcidin]. There was a greater percentage of maternally absorbed (58)Fe tracer present in the neonates compared to the (57)Fe tracer (5.4 ± 2.4 vs. 4.0 ± 1.6; P < 0.0001). Net dietary nonheme Fe (mg) and heme Fe (mg) transferred to the fetus were both inversely correlated with measures of maternal serum hepcidin (P = 0.002, r(2) = 0.43; P = 0.004, r(2) = 0.39) and SF (P = 0.0008, r(2) = 0.49; P = 0.003, r(2) = 0.41) and directly associated with neonatal Hb (P = 0.004, r(2) = 0.39; P = 0.008, r(2) = 0.35). The results of this study suggest that during pregnancy there appears to be preferential fetal use of maternally ingested Fe derived from a dietary, animal-based heme source compared to Fe ingested as ferrous sulfate. Maternal serum hepcidin and maternal/neonatal Fe status may play a role in placental uptake of dietary heme and nonheme Fe.
膳食铁的胎盘转运机制仍很大程度上不明确。本研究旨在阐明母体摄入血红素和非血红素铁后胎儿铁转移的决定因素。研究对象为 19 名处于妊娠晚期的孕妇（16-32 岁），她们在妊娠晚期同时摄入内标（58）Fe-血红素和非血红素铁源（（57）FeSO4）。分娩时采集母血和脐血，以评估新生儿（57）Fe 和（58）Fe 丰度与母体/新生儿铁状态的关系[血清铁蛋白（SF）、转铁蛋白受体、血红蛋白（Hb）、全身铁和铁调素]。与（57）Fe 示踪剂相比，新生儿体内存在更多的母体吸收（58）Fe 示踪剂（5.4±2.4%比 4.0±1.6%；P<0.0001）。胎儿摄入的膳食非血红素铁（mg）和血红素铁（mg）均与母体血清铁调素（P=0.002，r²=0.43；P=0.004，r²=0.39）和 SF（P=0.0008，r²=0.49；P=0.003，r²=0.41）呈负相关，与新生儿 Hb 呈正相关（P=0.004，r²=0.39；P=0.008，r²=0.35）。本研究结果表明，在妊娠期间，母体摄入的来源于膳食动物源血红素的铁似乎比摄入硫酸亚铁的铁更优先被胎儿利用。母体血清铁调素和母体/新生儿铁状态可能在胎盘摄取膳食血红素和非血红素铁中起作用。
