Case study on iron in mental development--in memory of John Beard (1947-2009)

Immune System and Psychological State of Pregnant Women during COVID-19 Pandemic: Are Micronutrients Able to Support Pregnancy?

The immune system is highly dynamic and susceptible to many alterations throughout pregnancy. Since December 2019, a pandemic caused by coronavirus disease 19 (COVID-19) has swept the globe. To contain the spread of COVID-19, immediate measures such as quarantine and isolation were implemented. These containment measures have contributed to exacerbate situations of anxiety and stress, especially in pregnant women, who are already particularly anxious about their condition. Alterations in the psychological state of pregnant women are related to alterations in the immune system, which is more vulnerable under stress. COVID-19 could therefore find fertile soil in these individuals and risk more severe forms. Normally a controlled dietary regimen is followed during pregnancy, but the use of particular vitamins and micronutrients can help counteract depressive-anxiety states and stress, can improve the immune system, and provide an additional weapon in the defense against COVID-19 to bring the pregnancy to fruition. This review aims to gather data on the impact of COVID-19 on the immune system and psychological condition of pregnant women and to assess whether some micronutrients can improve their psychophysical symptoms.

Selected Micronutrients: An Option to Boost Immunity against COVID-19 and Prevent Adverse Pregnancy Outcomes in Pregnant Women: A Narrative Review

The coronavirus disease-19 (COVID-19) negatively affects immune system. It is linked with adverse pregnancy outcomes. These complications may be linked with the infections mediated deficiency of micronutrients in pregnant women. COVID-19 cause's malabsorption of micronutrients thereby increases the risk of their deficiency. Both micronutrients deficiencies and poor micronutrients intake can compromise immune function and may increase the risk of pregnancy complications associated with COVID-19 infection. Vita-min A, C, D, E, and selected minerals iron (Fe), selenium (Se), and zinc (Zn) are the micronutrients essential for immuno-competency and play a significant role in the prevention of adverse pregnancy outcomes. Immune function and pregnancy outcomes can be improved by adequate intake of micronutrients in diet or in supplements form. Based on regulatory links between viral infection, micronutrients, immunity, and pregnancy outcomes, this review highlights the role of micronutrients in boosting immunity to reduce or prevent pregnancy complications in COVID-19 infected women.

Non-invasive measurement of erythrocyte zinc protoporphyrin in children

BACKGROUND

Reliable screening for iron deficiency (ID) has required a blood sample and cost-intensive laboratory measurements. A novel method to non-invasively measure erythrocyte zinc protoporphyrin (ZnPP), an established marker for ID, is evaluated in children.

METHODS

ZnPP was determined non-invasively by fluorescence measurements on the wet vermillion of the lower lip in 99 hospitalized children aged 9 months to 5 years. For comparison, conventional ID parameters and ZnPP were determined from blood samples.

RESULTS

The non-invasively measured ZnPP values had limits of agreement (LoA) of 14 µmol ZnPP/mol heme (95% confidence interval: 9-20) compared to fluorescence measurements directly in blood. Repeated high-performance liquid chromatography reference determinations had comparable LoA of 14 µmol ZnPP/mol heme (9-17). Non-invasive ZnPP measurements had sensitivity and specificity of 67% (39-88%) and 97% (91-99%), and negative and positive predictive value of 94% (90-97%) and 80% (55-93%), for detecting ID as defined by the soluble transferrin receptor (sTfR). In groups with more severe ID as defined by serum ferritin and sTfR, higher ZnPP values were found, with the highest ZnPP values for the group with ID anemia.

CONCLUSION

Non-invasive ZnPP measurements are reliably feasible in children. The simple and fast method has the potential to enable wide-spread screening for ID.

Minerals in Pregnancy and Lactation: A Review Article

Micronutrients (include vitamins and minerals) are essential for normal function, growth and development. Minerals have important effects on the health of the mother and foetus. But biological mechanisms of minerals are not completely understood. Micronutrient deficiency during pregnancy can lead to anaemia, hypertension, obstetric complications and even maternal death and in foetus lead to a fail in growth and development. Mineral deficiency during pregnancy, particularly exist in developing countries. During pregnancy due to the increased demands caused by physiological changes, deficiency is exaggerated and as a result its complications occur. Thus, ensuring to receive enough macronutrients and micronutrients before and during pregnancy, is important. Nevertheless, there are controversies regarding administrating supplements. There are not enough studies about some of the minerals and the challenges remain. Regarding the importance of minerals in pregnancy and lactation, in this review we will analyze the role of them in pregnancy and lactation.

Maternal Iron Status in Pregnancy and Long-Term Health Outcomes in the Offspring

Iron is an essential micronutrient and is important not only in carrying oxygen but also to the catalytic activity of a variety of enzymes. In the fetus, it is vital to the synthesis of hemoglobin and in brain development. Iron deficiency (ID) anemia in pregnancy is a common problem, even in high-income country settings. Around 50% of pregnant women worldwide are anemic, with at least half of this burden due to ID. Iron supplements are widely recommended and used during pregnancy globally. However, the evidence on the extent of benefit they contribute to the offspring's health is not well established, and their routine use has its side effects and drawbacks. Dietary iron intake is difficult to assess accurately and it is unlikely to be sufficient to meet the demands of pregnancy if women start with inadequate body iron stores at conception. Evidence from experimental animal models suggests that maternal ID during pregnancy is associated with fetal growth restriction, as well as offspring obesity and high blood pressure later in life. The possible biological mechanisms for this observed association may be due to ID-induced changes in placental structure and function, enzyme expression, nutrient absorption, and fetal organ development. However, such evidence is limited in human studies. Prenatal ID in experimental animal models also adversely affected the developing brain structures, neurotransmitter systems, and myelination resulting in acute brain dysfunction during the period of deficiency and persistence of various postnatal neurobehavioral abnormalities as well as persistent dysregulation of some genes into adult life after iron repletion pointing to the possibility of gene expression changes. The evidence from human population studies is limited and heterogeneous and more research is needed in the future, investigating the effects of ID in pregnancy on future offspring health outcomes.

Anaemia of pregnancy, perinatal outcomes and children's developmental vulnerability: a whole-of-population study

BACKGROUND

There is limited longitudinal data from high-income countries on the sequelae of anaemia during pregnancy. The aim of this study is to examine whether anaemia of pregnancy is associated with adverse perinatal outcomes and with children's developmental vulnerability.

METHODS

We conducted a population-based study to link routinely collected government administrative data that involved all live births in the state of South Australia 1999-2005 (n = 124 061) and a subset for whom developmental data were collected during a national census of children attending their first year of school in 2009 (n = 13 654). Perinatal outcomes were recorded by midwives using a validated, standardised form. Development was recorded by schoolteachers using the Australian Early Development Index (AEDI). Children in the lowest 10% of AEDI scores are indicative of developmental vulnerability.

RESULTS

There were 8764/124 061 (7.1%) cases of anaemia. After adjustment for a range of potentially confounding factors, anaemia of pregnancy was associated with a higher risk of fetal distress [incident rate ratio (IRR) 1.20 [95% CI 1.13, 1.27]] and preterm birth <37 weeks gestation (IRR 1.23 [1.15, 1.31]), slightly higher birthweight [14 g (2, 26)] and newborns were less likely to require resuscitation (IRR 0.94 [0.91, 0.097]). Anaemia of pregnancy was not associated with children's developmental vulnerability after adjustment for maternal, obstetric and sociodemographic covariables, either in complete case analyses (n = 11 949) or after imputation for missing data (n = 13 654).

CONCLUSIONS

Anaemia of pregnancy is associated with perinatal complications but not with children's developmental vulnerability at school entry.

Effect modification by transferrin C2 polymorphism on lead exposure, hemoglobin levels, and IQ

BACKGROUND

Iron deficiency and lead exposure remain significant public health issues in many parts of the world and are both independently associated with neurocognitive deficits. Polymorphisms in iron transport pathways have been shown to modify the absorption and toxicity of lead.

OBJECTIVE

We hypothesized that the transferrin (TF) C2 polymorphism modifies the effects of lead and hemoglobin on intelligence.

METHODS

Children aged 3-7 years (N=708) were enrolled from 12 primary schools in Chennai, India. The Binet-Kamath Scale of Intelligence were administered to ascertain intelligence quotient (IQ). Venous blood was analyzed for lead and hemoglobin levels. Genotyping for the TF C2 polymorphism (rs1049296) was carried out using a MassARRAY iPLEXTM platform. Stratified analyses and interaction models, using generalized estimating equations, were examined to explore interactions between lead, hemoglobin, and TF C2 categories.

RESULTS

A one-unit increase in log blood lead and 1g/dl higher hemoglobin was associated with -77 (95% CI: -136, -18) and 17 (95% CI 14, 21) IQ points, respectively, among children carrying the C2 variant. In comparison, among children who had the homozygous wildtype allele, the same increment of lead and hemoglobin were associated with -21(95% CI: -65, 24) and 28 (95% CI: 15, 40) IQ points, respectively. There was a significant interaction between lead (p=0.04) and hemoglobin (p=0.07) with the C2 variant.

CONCLUSION

Children who carry the TF C2 variant may be more susceptible to the neurotoxic effects of lead exposure and less protected by higher levels of hemoglobin.

Iron deficiency in women: assessment, causes and consequences

PURPOSE OF REVIEW

Iron deficiency is the most common nutritional disorder affecting about 20-25% of the world's population, predominantly children and women. There is emerging evidence that depletion of iron stores may have adverse consequences for adults even in the absence of anaemia. This raises issues about the most appropriate method of assessing iron status.

RECENT FINDINGS

Although the effects of iron-deficiency anaemia are well characterized, emerging evidence suggests that iron deficiency without anaemia can have negative consequences in adults, particularly for neurocognitive outcomes. Iron deficiency is more likely in women of reproductive age because of menstrual blood loss. However, extremes of blood loss such as regular blood donation, diets of low bioavailability and the challenges of pregnancy all markedly increase the risk of iron deficiency. In addition, the physiological changes in pregnancy affect the normal reference ranges used in laboratory assessment. The use of haemoglobin as a marker of iron deficiency is limited by its low specificity and sensitivity and although the use of alternative biomarkers is becoming more common, interpreting results in conditions of chronic inflammation, including that associated with increased adiposity, needs more investigation.

SUMMARY

By understanding the physiology of iron metabolism alongside the limitations and interpretation of biomarkers of iron deficiency, clinicians and nutritionists are better equipped to identify changes in iron balance and to further investigate the functional outcomes of iron deficiency.

Micronutrients in pregnancy: current knowledge and unresolved questions

Micronutrient status is increasingly recognized to play an important role in the health and well-being of pregnant women and in the development and long-term health of the offspring. On 26th - 28th February 2009, The Child Health Foundation invited leading experts in this area to a scientific workshop at Obergurgl, Austria to review and critically discuss current knowledge, to identify issues that may need to be addressed in future recommendations, and to highlight priorities and opportunities for future research. This report summarizes updated key conclusions of the workshop with regards to micronutrients' intake and physiological role related to mother, placenta and fetus, as well as relevance for adverse pregnancy and long-term outcomes.

Nutrition and cognition: meeting the challenge to obtain credible and evidence-based facts

Nutrition provides a practical and appealing approach to cognitive enhancement, including the modulation of long-term cognitive processes such as neurodevelopment and neurodegeneration. An abundance of promising nutritional influences on cognition have been identified, but many long-term effects remain to be confirmed by data from randomized controlled trials (RCTs). The current article provides a general outline of various factors that hamper the demonstration of causal long-term nutritional effects on cognition by RCTs and advocates the development of methodological solutions to enable substantiation in future RCTs.