Iron deficiency is common worldwide and is associated with adverse pregnancy outcomes. The increasing prevalence of indiscriminate iron supplementation during pregnancy also raises concerns about the potential adverse effects of iron excess. We examined how maternal iron status affects the delivery of iron to the placenta and fetus. Using mouse models, we documented maternal homeostatic mechanisms which protect the placenta and fetus from maternal iron excess. We determined that under physiological conditions or in iron deficiency, fetal and placental hepcidin does not regulate fetal iron endowment. With maternal iron deficiency, critical transporters mediating placental iron uptake (transferrin receptor 1, TFR1) and export (ferroportin, FPN) were strongly regulated. In mice, not only was TFR1 increased but FPN was surprisingly decreased to preserve placental iron, in the face of fetal iron deficiency. In human placentas from pregnancies with mild iron deficiency, TFR1 was increased but without a change in FPN. However, induction of more severe iron deficiency in human trophoblast in vitro resulted in the regulation of both TFR1 and FPN, similarly to the mouse model. This placental adaptation prioritizing placental iron is mediated by the iron-regulatory protein 1 and is important for the maintenance of mitochondrial respiration, thus ultimately protecting the fetus from the potentially dire consequences of generalized placental dysfunction.

Hepcidin is the master regulator of systemic iron bioavailability in humans. This review examines primary research articles that assessed hepcidin during pregnancy and postpartum and report its relationship to maternal and infant iron status and birth outcomes; areas for future research are also discussed. A systematic search of the databases Medline and Cumulative Index to Nursing and Allied Health returned 16 primary research articles including 10 human and six animal studies. Collectively, the results indicate that hepcidin is lower during pregnancy than in a non-pregnant state, presumably to ensure greater iron bioavailability to the mother and fetus. Pregnant women with undetectable serum hepcidin transferred a greater quantity of maternally ingested iron to their fetus compared to women with detectable hepcidin, indicating that maternal hepcidin in part determines the iron bioavailability to the fetus. However, inflammatory states, including preeclampsia, malaria infection, and obesity were associated with higher hepcidin during pregnancy compared to healthy controls, suggesting that maternal and fetal iron bioavailability could be compromised in such conditions. Future studies should examine the relative contribution of maternal versus fetal hepcidin to the control of placental iron transfer as well as optimizing maternal and fetal iron bioavailability in pregnancies complicated by inflammation.

To date, Healthy Eating Index 2015 (HEI-2015) scores have not been published in the peer-reviewed literature for nationally representative samples of American children. The aim of this study was to use the HEI-2015 to describe the diet quality of American children overall and within various sociodemographic populations. We used 3 cycles of NHANES dietary data sets (2009-2010, 2011-2012, and 2013-2014) to calculate HEI-2015 total and component scores by use of the population ratio method for children aged 2-18 y (n = 9000). Diet-quality scores were computed overall and by age (2-5, 6-11, and 12-18 y), gender, race or ethnicity (non-Hispanic black, non-Hispanic white, Mexican American, other Hispanic, and other race), and family poverty-to-income ratio (below or at or above the poverty threshold). HEI-2015 mean total and component scores were computed along with 95% CIs. The HEI-2015 total mean score for children overall was 54.9 (range: 0-100). As the age group increased, the total scores decreased; the total mean score was significantly higher for children in the youngest age group compared with the 2 older age groups (60.1 compared with 53.9 compared with 52.0, respectively). The total mean score was significantly lower for non-Hispanic black children compared with Mexican American children, other Hispanic children, and children of other races (52.6 compared with 57.0, 56.8, and 57.1, respectively). The total mean score was significantly lower for non-Hispanic white children compared with Mexican-American children (54.2 compared with 57.0). No differences in total mean scores were apparent between boys and girls or between poverty threshold classes. The total mean scores for cross-classified sociodemographic characteristics generally followed the same patterns observed for single characteristics, with notable differences occurring within age and race or ethnicity classes. The diet quality of American children remains low overall, with continued disparities across some sociodemographic populations, notably age and race or ethnicity. The results of these analyses can help guide the efforts of child nutrition researchers, practitioners, and other stakeholders.

Accumulating evidence suggests that higher Mediterranean diet (MedDiet) adherence is associated with higher global cognitive performance and brain structural integrity as well as decreased risk of Alzheimer disease (AD) and vascular dementia (VaD). We directly examined cross-sectional associations between the MedDiet and cognitive and neuroimaging phenotypes associated with AD and VaD (separately) in a cohort of nondemented, nondepressed older adults. Community-dwelling older adults (n = 82; aged ∼68.8 y; 50% female, 50% minority) underwent dietary (Block Food Frequency Questionnaire 2005) and neuropsychological assessments and neuroimaging. MedDiet scores were quantified with the use of published criteria, and participants were divided into High and Low (median split) adherence groups. We focused our neuropsychological investigation on cognitive phenotypes primarily associated with AD [i.e., learning and memory (L&M)] and VaD (i.e., information processing and executive functioning). AD neuroimaging phenotypes consisted of hippocampal and dentate gyrus volumes quantified using T1-weighted images and the FreeSurfer 6.0 segmentation pipeline (http://surfer.nmr.mgh.harvard.edu). The VaD neuroimaging phenotype consisted of total white matter hyperintensity (WMH) volumes quantified using combined T1-weighted and T2-fluid-attenuated inversion recovery images. Neuroimaging metrics were adjusted for total intracranial volume. Separate multivariable linear regression models controlling for age, sex, education, body mass index, and caloric intake examined the associations between MedDiet groups (High compared with Low) and cognitive and neuroimaging outcomes. When compared with the Low MedDiet group, the High MedDiet group was associated with better L&M performance and larger dentate gyri. MedDiet adherence was not associated with information processing, executive functioning, or WMH. Results highlight the association between increasing MedDiet adherence and specific cognitive and neuroimaging phenotypes that, when altered, are associated with AD.

Background: Strategies to prevent iron deficiency anemia (IDA) have varying effectiveness. The purpose of this systematic review of the literature and meta-analysis was to examine the effects of probiotics on iron absorption and iron status-related markers in humans. Methods: We followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) reporting guidelines. Relevant articles were identified from Embase, Pubmed, Scopus, and CINAHL from inception to February, 2019. We conducted a meta-analysis for eight studies examining the effect of the probiotic Lactobacillus plantarum 299v (Lp299v) on iron absorption. Results: Fifteen studies reported in 12 articles were identified (N = 950). Our meta-analysis of eight studies using a random-effects model demonstrated a significant increase in iron absorption following administration of the probiotic Lp299v with a pooled standardized mean difference (an average intervention effect size) of 0.55 (95% CI 0.22–0.88, p = 0.001). Of the seven randomized clinical trials (RCTs) and nonrandomized clinical trials examining a range of probiotic species on iron status, only one study supplementing with Lp299v showed improvement in serum iron; no other studies reported improvement in iron status-related indices with probiotic treatment. Conclusions: Lp299v significantly improved iron absorption in humans. Future research should include the assessment of Lp299v effect on iron absorption and iron status in populations at high risk of IDA, including pregnant women.