Iron Deficiency and Iron Homeostasis in Low Birth Weight Preterm Infants: A Systematic Review

Mineral supplementation for very preterm infants fed fortified human milk

OBJECTIVES

The safety and feasibility of human milk fortification with bovine colostrum (BC) were investigated in very preterm infants (FortiColos trial, NCT03537365). The BC product contained lower calcium, phosphate, and iron levels compared to the conventional fortifier (CF). We tested whether fortification with BC plus extra phosphate was sufficient to support the infants' mineral status assessed by blood biochemistry.

METHODS

In a randomised controlled trial (FortiColos, NCT03537365), mineral status was compared after fortification with BC versus CF. Blood calcium, phosphate, and haemoglobin were determined before and up to 3 weeks after the start of fortification (at the mean age of 8-9 days). The maximum supplemental doses of calcium, phosphate, and iron given were retrieved from patient medical records. Results were adjusted for gestational age, birth weight, and enteral nutrition with the mother's own milk and/or donor human milk.

RESULTS

Blood values of calcium, phosphate, and haemoglobin were similar between groups. Infants in both groups required supplementation with calcium and phosphate, but infants fed BC required higher maximum doses of phosphate and calcium (p < 0.05) to maintain acceptable blood values. Regardless of fortification groups, the most immature (<29 weeks of gestation) and small for gestational age infants showed a higher risk for requiring additional phosphate (odds ratio [OR]: 3.9, p < 0.001; OR: 2.14, p = 0.07, respectively).

CONCLUSIONS

The use of BC as a fortifier for human milk requires additional phosphate and calcium relative to a CF. Regardless of the fortification product, the most immature and small infants require additional mineral supplementation.

Hyperferritinemia among very-low-birthweight infants in Thailand: a prospective cohort study

OBJECTIVES

To determine the incidence of hyperferritinemia in VLBW infants, and its association with neonatal morbidity.

STUDY DESIGN

Prospective cohort study in a tertiary-level hospital in Bangkok, from March 2022 to January 2023. Serum ferritin (SF) was measured in VLBW infants at one month and repeated monthly for those with hyperferritinemia (SF > 300 ng/mL).

RESULTS

Gestational age and birth weight were 29.7 ± 2.4 weeks (mean ± SD) and 1100 g (IQR, 830, 1340). Hyperferritinemia was identified in 30.1% (95% CI, 20.8-41.4). After adjustment, only packed red cell transfusion >15 mL/kg was associated with hyperferritinemia (RR 3.1; 95% CI, 1.5-6.4). All elevated SF levels returned to normal within four months. Hyperferritinemia was associated with severe bronchopulmonary dysplasia (RR 2.3, 95% CI, 1.0-5.4) and retinopathy of prematurity (RR 3.5, 95% CI, 1.4-8.6).

CONCLUSION

Hyperferritinemia is common among our VLBW infants, particularly after transfusion, and is associated with severe BPD and ROP.

Prevalence and predictors of anemia among six-week-old infants in Kwale County, Kenya: A cross-sectional study

Anemia is a significant public health problem among children worldwide. The etiology of anemia is multifactorial but iron deficiency (ID) is the most common cause of anemia in low- and middle-income countries. ID and anemia in infancy can impair growth and cognitive development. The aim of this study was to determine the prevalence and predictors of anemia among six-week-old infants in Kwale County, Kenya. This cross-sectional study included 424 mother-infant pairs. Structured questionnaires were administered to the mothers to obtain information on socio-demographic variables, maternal characteristics and birth information. Anthropometric data was collected for each child. A heel prick was done to measure hemoglobin and zinc protoporphyrin concentration levels. Chi-square test, bivariate and multivariate regression analyses were done to determine factors associated with anemia. The prevalence of ID, anemia and IDA was 60.4% (95%CI: 55.9-65.2), 21.0% (95%CI: 17.5-25.2) and 15.8% (95%CI: 12.7-19.7) respectively. Bivariate analysis showed that the risk of anemia was significantly higher among male infants (odds ratio (OR) = 2.20 (95%CI: 1.33-3.63), p = 0.002), iron deficient infants (OR = 2.35 (95%CI: 1.39-3.99), p = 0.001) and infants from Msambweni Sub-County (OR = 2.80 (95%CI: 1.40-4.62), p<0.001). Multivariate analysis revealed that odds of anemia were significantly higher in infants born to mothers who did not use iron supplements during pregnancy (adjusted odds ratio (aOR) = 74.01 (95%CI: 2.45-2238.21), p = 0.013 and significantly lower in infants born to mothers with parity ≥ 4 (aOR = 0.05 ((95%CI: 0.00-0.77), p = 0.024). In six-week-old infants in rural Kenya, anemia prevalence was 21.0% with ID accounting for 75.3% of anemia cases. Given the physical and cognitive impairments associated with ID and anemia in early infancy, it may be prudent to re-evaluate the current Kenyan pediatric protocols to include anemia screening and potential treatment of infants less than 6-months of age.

Non Breast-Milk-Fed Very Preterm Infants Are at Increased Risk of Iron Deficiency at 4-6-Months Corrected Age: A Retrospective Population-Based Cohort Study

Iron supplementation is routinely recommended for breast-milk-fed preterm infants. However, the Canadian Pediatric Society recommends no additional iron supplementation for preterm infants fed primarily with iron-rich formula. Other pediatric societies don't provide specific guidance on supplemental iron for formula-fed preterm infants. This study investigated how feeding type influences iron status of very preterm infants at 4-6-months corrected age (CA). A retrospective cohort study was conducted using a population-based database on all very preterm infants (<31 weeks gestational age) born in Nova Scotia, Canada from 2005-2018. Information about feeding type, iron intake from formula, supplemental iron therapy and iron status at 4-6-months CA was extracted. Iron deficiency (ID) was defined as serum ferritin <20 and <12 µg/L at 4-and 6-months CA, respectively. Of 392 infants, 107 were "breast-milk-fed" (exclusively or partially) and 285 were "not breast-milk-fed" (exclusively fed with iron-rich formula) at 4-6-months CA. Total daily iron intake was higher in the non-breast-milk-fed group (2.6 mg/kg/day versus 2.0 mg/kg/day). Despite this, 36.8% of non-breast-milk-fed infants developed ID versus 20.6% of breast-milk-fed infants. ID is significantly more prevalent in non-breast-milk-fed infants than breast-milk-fed infants despite higher iron intake. This suggests the need to revisit recommendations for iron supplementation in non-breast-milk-fed preterm infants.

Iron Intake and Human Health

Iron deficiency anemia (IDA) is a global nutritional disorder affecting large population groups in varying magnitudes in different countries [...].

Iron Deficiency Prior to Discharge in Very Low Birth Weight Infants: Screening with Reticulocyte Hemoglobin Content

OBJECTIVE

 This study aimed to assess the iron status prior to discharge in very low birth weight (VLBW) infants utilizing reticulocyte hemoglobin content (CHr) and evaluate the impact of delayed cord clamping (DCC) on iron status.

STUDY DESIGN

 This is a retrospective analysis of VLBW infants from two tertiary level of care Neonatal Intensive Care Units. The primary outcome was the proportion of VLBW infants with low CHr (<29 pg) prior to discharge. Hematologic parameters were also compared between infants who received or did not receive DCC. Infants with a positive newborn screen for hemoglobin Bart's were excluded.

RESULTS

 Among the 315 infants included, 99 infants (31.4%) had low CHr prior to discharge. The median (interquartile range) CHr prior to discharge was 30.8 pg (28.4-39 pg). DCC was performed in 46.7% of infants. Hemoglobin at birth, discharge, and CHr prior to discharge were higher and the need for blood transfusion and the number of infants with low CHr prior to discharge were lower in the DCC group.

CONCLUSION

 Approximately 31.4% of VLBW infants had low CHr near the time of discharge suggesting they were iron deficient. DCC improved hematological parameters prior to discharge in VLBW infants. CHr content can be used to guide iron supplementation in VLBW infants to potentially improve their iron status and long-term neurocognitive outcomes.

KEY POINTS

· DCC was associated with an improved hemoglobin and iron status at discharge in VLBW infants.. · CHr is an early and reliable marker for iron deficiency.. · Approximately one in three VLBW infants can be iron deficient at the time of discharge..

Effectiveness and safety of umbilical cord milking in premature infants: A randomized controlled trial

INTRODUCTION

Both UCM and DCC are used to treat preterm infants, but there is no uniform standard for the length of UCM. The aim of this work was to explore the effectiveness and safety of different umbilical cord milking (UCM) lengths versus delayed cord clamping (DCC).

METHODS

We enrolled premature infants from the Affiliated Hospital of Zunyi Medical University between September 2019 and October 2020 with random allocation (1:1:1:1) to the UCM 10 cm, UCM 20 cm, UCM 30 cm, and DCC groups. The primary outcome was hemoglobin at birth.

RESULTS

Ultimately, 143 participants completed the trial (UCM 10 cm, n = 35; UCM 20 cm, n = 35; UCM 30 cm, n = 38; DCC, n = 35). The hemoglobin levels were significantly lower at birth in the UCM 10 cm group than in the UCM 20 and 30 cm and DCC groups (182.29 ± 22.15 vs 202.83 ± 21.46, 208.82 ± 20.72, and 198.46 ± 24.92, P = .001, .001, and .003, respectively). The systolic blood pressure and diastolic pressures in the UCM 30 cm group were higher than those in the UCM 10 and 20 cm and DCC groups at birth, postnatal day 3 and postnatal day 7 (P < .05). The occurrence rates of anemia were significantly higher in the UCM 10 cm group than in the UCM 20 and 30 cm and DCC groups (42.9% vs 14.3%, 10.5%, and 14.3%, all P < .0083). There were no significant differences in heart rate or complications among the 4 groups.

CONCLUSIONS

A UCM of 20 or 30 cm is a safe, effective operation for preterm infants and could improve blood pressure and hemoglobin levels and reduce anemia.

Biofortification revisited: Addressing the role of beneficial soil microbes for enhancing trace elements concentration in staple crops

Trace element deficiency is a pervasive issue contributing to malnutrition on a global scale. The primary cause of this hidden hunger is related to low dietary intake of essential trace elements, which is highly prevalent in numerous regions across the world. To address deficiency diseases in humans, fortification of staple crops with vital trace elements has emerged as a viable solution. Current methods for fortifying crops encompass chemical amendments, genetic breeding, and transgenic approaches, yet these approaches possess certain limitations, constraining their agricultural application. In contrast, fortifying staple crops through the utilization of soil-beneficial microbes has emerged as a promising and economically feasible approach to enhance trace element content in crops. A specific subset of these beneficial soil microbes, referred to as plant growth-promoting microbes, have demonstrated their ability to influence the interactions between plants, soil, and minerals. These microbes facilitate the transport of essential soil minerals, such as zinc, iron, and selenium, into plants, offering the potential for the development of tailored bioinoculants that can enhance the nutritional quality of cereals, pulses, and vegetable crops. Nevertheless, further research efforts are necessary to comprehensively understand the molecular mechanisms underlying the uptake, transport, and augmentation of trace element concentrations in staple crops. By delving deeper into these mechanisms, customized bioinoculants of soil-beneficial microbes can be developed to serve as highly effective strategies in combating trace element deficiency and promoting global nutritional well-being.

The Emerging Roles of Ferroptosis in Neonatal Diseases

Ferroptosis is a novel type of programmed cell death involved in many diseases' pathological processes. Ferroptosis is characterized by lipid peroxidation, reactive oxygen species accumulation, and iron metabolism disorder. Newborns are susceptible to ferroptosis due to their special physiological state, which is prone to abnormal iron metabolism and the accumulation of reactive oxygen species. Recent studies have linked ferroptosis to a variety of diseases in the neonatal period (including hypoxic-ischemic encephalopathy, bronchopulmonary dysplasia, and necrotizing enterocolitis). Ferroptosis may become an effective target for the treatment of neonatal-related diseases. In this review, the ferroptosis molecular mechanism, metabolism characteristics of iron and reactive oxygen species in infants, the relationship between ferroptosis and common infant disorders, and the treatment of infant diseases targeted for ferroptosis are systematically summarized.

Effects of early introduction of solid foods on nutrient intake in preterm infants during their 1st year of life: a secondary outcome analysis of a prospective, randomized intervention study

Very low birth weight (VLBW) infants have higher nutritional needs even after hospital discharge. However, data concerning current nutrient intakes at different time points after the introduction of solid foods and whether dietary reference values are being met are scarce. To adress this issue, this secondary analysis of a prospective, two-arm interventional study in 177 VLBW infants 21 investigates dietary intake comparing early and late (early: 10-12 weeks corrected for gestational age, late: 16-18 weeks corrected for gestational age) introduction of standardized complementary food during the first year of life. Nutritional intake was assessed using self-reported monthly 3-day dietary records from 3 until 12 months, corrected for gestational age. The time point of the introduction of solid foods did not influence nutrient intake, but the early introduction of solids tended toward a higher proportional intake of protein and carbohydrates and a lower intake of fat as a percentage of total energy) during the 1st year of life, corrected for gestational age. The results of this study indicate that this standardized feeding concept was sufficient for zinc, calcium, and phosphorus intake. However, dietary iron and vitamin D intakes did not meet the recommendations. Thus, prolonged iron supplementation should be considered beyond the introduction of meat and vitamin D supplementation at least until 12 months, corrected for gestational age.

Trial registration number

ClinicalTrials.gov: NCT01809548.

Hematological changes in neonatal mice with phlebotomy-induced anemia

BACKGROUND

Anemia is a nearly universal diagnosis in preterm infants, caused by phlebotomy, and exacerbated by the underlying erythropoietic immaturity. Newborn infants are exposed to the unique stressor of fetal-to-neonatal transition, which requires significant adaptation ex utero. Accordingly, the preterm infant's response to anemia may alter the ability to confront underlying illness. This study utilized our preclinical mouse model of phlebotomy-induced anemia (PIA) to comprehensively investigate associated hematological changes.

METHODS

C57BL/6 mice were subjected to timed phlebotomy between postnatal days 2--10 to induce severe anemia. Complete blood counts were determined by the Sysmex XT-2000iV analyzer.

RESULTS

Anemic pups showed a gradual reduction of RBC and hemoglobin (Hb) and increased reticulocyte (RET) counts and red cell distribution width (RDW), however, with reduced RET-Hb from postnatal day (P) of 4 onwards. Elevated levels of high fluorescent RET and immature reticulocyte fraction (IRF) were noted in anemic mouse pups, but low and medium fluorescent RET were reduced. Also, the reduction of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were noted in anemic pups. No changes were seen in lymphocytes, but monocytes and neutrophils were significantly elevated from P4-P6.

CONCLUSIONS

PIA in mouse pups is associated with hematological changes that may be exacerbating factors in neonatal diseases.

IMPACT

Anemia is common and often severe in premature infants. Investigation of hematological parameters in settings of preclinical anemia may be an index of therapeutic strategies. Preclinical model evaluating the effects of neonatal anemia on the remainder of complete blood count. Detailed time kinetic phlebotomy-induced anemic mice enable us to study the impact on developmental delays in erythropoiesis and possible strategic intervention. Hematological effects of severe anemia in mice might provide insight on how best to investigate anemia in preterm infants.

The effect of individualized iron supplementation on iron status in Dutch preterm infants born between 32 and 35 weeks of gestational age: evaluation of a local guideline

OBJECTIVE

Iron deficiency (ID) and iron deficiency anemia (IDA) in early life are associated with adverse effects. Preterm infants are at risk for developing ID(A). Considering that not every preterm infant develops ID(A) and the potential risk of iron overload, indiscriminate iron supplementation in late preterm infants is debatable. This study aimed to evaluate the effect of a locally implemented guideline regarding individualized iron supplementation on the prevalence of ID(A) at the postnatal age of 4-6 months in Dutch preterm infants born between 32 and 35 weeks of gestational age (GA).

METHODS

An observational study comparing the prevalence of ID(A) at the postnatal age of 4-6 months in Dutch preterm infants born between 32 and 35 weeks of GA before (i.e. PRE-guideline group) and after (i.e. POST-guideline group) implementation of the local guideline.

RESULTS

Out of 372 eligible preterm infants, 110 were included (i.e. 72 and 38 in the PRE- and POST-guideline group, respectively). ID- and IDA-prevalence rates at 4-6 months of age in the PRE-guideline group were 36.1% and 13.9%, respectively, and in the POST-guideline group, 21.1% and 7.9%, respectively, resulting in a significant decrease in ID-prevalence of 15% and IDA-prevalence of 6%. No indication of iron overload was found.

CONCLUSION

An individualized iron supplementation guideline for preterm infants born between 32 and 35 weeks GA reduces ID(A) at the postnatal age of 4-6 months without indication of iron overload.

Effects of iron deficiency and iron supplementation at the host-microbiota interface: Could a piglet model unravel complexities of the underlying mechanisms?

Iron deficiency is the most prevalent human micronutrient deficiency, disrupting the physiological development of millions of infants and children. Oral iron supplementation is used to address iron-deficiency anemia and reduce associated stunting but can promote infection risk since restriction of iron availability serves as an innate immune mechanism against invading pathogens. Raised iron availability is associated with an increase in enteric pathogens, especially Enterobacteriaceae species, accompanied by reductions in beneficial bacteria such as Bifidobacteria and lactobacilli and may skew the pattern of gut microbiota development. Since the gut microbiota is the primary driver of immune development, deviations from normal patterns of bacterial succession in early life can have long-term implications for immune functionality. There is a paucity of knowledge regarding how both iron deficiency and luminal iron availability affect gut microbiota development, or the subsequent impact on immunity, which are likely to be contributors to the increased risk of infection. Piglets are naturally iron deficient. This is largely due to their low iron endowments at birth (primarily due to large litter sizes), and their rapid growth combined with the low iron levels in sow milk. Thus, piglets consistently become iron deficient within days of birth which rapidly progresses to anemia in the absence of iron supplementation. Moreover, like humans, pigs are omnivorous and share many characteristics of human gut physiology, microbiota and immunity. In addition, their precocial nature permits early maternal separation, individual housing, and tight control of nutritional intake. Here, we highlight the advantages of piglets as valuable and highly relevant models for human infants in promoting understanding of how early iron status impacts physiological development. We also indicate how piglets offer potential to unravel the complexities of microbiota-immune responses during iron deficiency and in response to iron supplementation, and the link between these and increased risk of infectious disease.

Postdischarge Iron Status in Very Preterm Infants Receiving Prophylactic Iron Supplementation after Birth

OBJECTIVE

To determine postdischarge iron status and associated factors in very preterm infants.

STUDY DESIGN

A retrospective cohort study was conducted through a provincial database on all very preterm infants born in Nova Scotia between 2005 and 2018. As a standard of care, all infants received prophylactic iron supplements starting at 2-4 weeks of chronological age and were tested for iron deficiency at 4 or 6 months corrected age. Iron deficiency was defined as serum ferritin <20 g/L at 4 months or <12 g/L at 6 months. Multivariate logistic regression analysis identified factors associated with iron deficiency.

RESULTS

Among 411 infants, 132 (32.1%) had iron deficiency and 11 (2.7%) had iron deficiency anemia. The prevalence of iron deficiency decreased over time, from 37.6% in 2005-2011 to 25.8% in 2012-2018. Gestational hypertension in the mother (P = .01) and gestational age <27 weeks (P = .02) were independent risk factors for iron deficiency. In addition, the odds of iron deficiency were lower in the mixed-fed group (ie, with breast milk and formula combined) compared with the exclusive formula-fed group (P = .01).

CONCLUSIONS

Iron deficiency was prevalent in 32% of the very preterm infants despite early iron prophylaxis. These results demonstrate the importance of monitoring iron stores during preterm follow-up. Information about risk factors is important to mitigate iron deficiency in very preterm infants.

Preterm Infants on Early Solid Foods and Iron Status in the First Year of Life—A Secondary Outcome Analysis of a Randomized Controlled Trial

Introduction of solid foods and iron status in the first year of life of preterm infants are highly discussed topics. The aim of this study was to examine whether two timepoints of introduction of standardized solid foods in preterm infants have an impact on ferritin and other hematologic parameters important for iron status in the first year of life. This is a secondary outcome analysis of a prospective, randomized intervention trial in very low birth weight (VLBW) infants randomized to an early (10–12th week corrected age) or a late (16–18th week corrected age) complementary feeding group. Iron status was assessed with blood samples taken at 6 weeks, 6 months, and 12 months corrected age. In total, 177 infants were randomized (early group: n = 89, late group: n = 88). Ferritin showed no differences between study groups throughout the first year of life, as did all other parameters associated with iron status. At 12 months corrected age, the incidence of iron deficiency was significantly higher in the early feeding group. There is room for improvement of iron status in VLBW preterm infants, regular blood checks should be introduced, and current recommendations may need to be a reconsidered.

Optimizing iron supplementation by monitoring serum ferritin levels in premature infants

BACKGROUND

Iron (Fe) is essential for growth, but optimal intake is controversial. Our NICU practice was to supplement 2 mg/kg/d Fe for all preterm infants receiving human milk when they achieved full feeding volume. Adjusting Fe supplementation based on ferritin levels is thought to better address physiologic requirements. Our objective was to assess the impact of therapeutic monitoring of ferritin levels on the initiation and dosing of iron supplementation, hematocrit, transfusions, and oxygen radical diseases in preterm infants.

METHODS

Preterm infants (<  32 weeks gestation, n = 100) were included. Ferritin was measured when full feeds were achieved, and then every 2 weeks. Fe was started at 2 mg/kg/d or continued at current dose for ferritin 40-300μg/L, increased by 1-2 mg/kg/d for <  40μg/L, or discontinued for >  300μg/L. Outcomes were compared with a historical control group.

RESULTS

Ferritin levels were not predictable by dietary or transfusion histories. Using the ferritin protocol, 70% of infants received Fe at the time of full feeds, compared to 100% of controls. In contrast, all infants received Fe 4 weeks later, compared to 87% of controls. Mean age at Fe initiation increased (14.8±6.3 to 21.0±11.76 days). Peak doses were higher, with 32% receiving >  2 mg/kg day by 6 weeks, with fewer transfusions. The incidence of bronchopulmonary dysplasia and necrotizing enterocolitis did not change.

CONCLUSION

An iron protocol based on ferritin levels results in later initiation, higher doses, and fewer transfusions, without increasing oxygen radical diseases.

Neonatal hyperleukocytosis and regenerative anemia in a septic puppy

This paper reports a case of neonatal hyperleukocytosis in a dog due to a bacterial infection. A 3-week-old, mixed-breed dog was brought to a veterinary college referral center with a history of weight loss despite a good appetite. Clinical and laboratory examinations included: physical examination, complete blood (cell) count (CBC), serum biochemistry profile, abdominal ultrasound examination, and cytology of liver and bone marrow aspirates. The CBC showed hyperleukocytosis of 158.0 × 10⁹/L (RI: 2.1 to 21.2 × 10⁹/L) and hematocrit of 0.19 L/L (RI: 0.21 to 0.34 L/L). The strong leukemoid reaction was comprised of neutrophils, monocytes, and lymphocytes. The dog was diagnosed with Staphylococcus pseudointermedius liver infection based on liver aspirates and culture. Amoxicillin-clavulanic acid was prescribed. A recheck abdominal ultrasound and CBC repeated 4 wk after initial examination were unremarkable. Neonatal hyperleukocytosis is well-described in human medicine but veterinary studies in small animal neonates are scarce. Key clinical message: Hyperleukocytosis in adult dogs may be caused by leukemia or leukemoid reactions. Generalized sepsis is a leading cause of leukemoid reactions in adult dogs and cats. In puppies, neoplasia is less likely, and other causes should be investigated. Similar to human neonates, puppies can mount a strong leukemoid reaction during an infection, even if it is not a generalized septic process.

Dietary Approaches to Iron Deficiency Prevention in Childhood—A Critical Public Health Issue

Iron is an essential nutrient, and individual iron status is determined by the regulation of iron absorption, which is driven by iron requirements. Iron deficiency (ID) disproportionately affects infants, children, and adolescents, particularly those who live in areas with unfavorable socioeconomic conditions. The main reason for this is that diet provides insufficient bioavailable iron to meet their needs. The consequences of ID include poor immune function and response to vaccination, and moderate ID anemia is associated with depressed neurodevelopment and impaired cognitive and academic performances. The persistently high prevalence of ID worldwide leads to the need for effective measures of ID prevention. The main strategies include the dietary diversification of foods with more bioavailable iron and/or the use of iron-fortified staple foods such as formula or cereals. However, this strategy may be limited due to its cost, especially in low-income countries where biofortification is a promising approach. Another option is iron supplementation. In terms of health policy, the choice between mass and targeted ID prevention depends on local conditions. In any case, this remains a critical public health issue in many countries that must be taken into consideration, especially in children under 5 years of age.

The Influence of Nutritional Supplementation for Iron Deficiency Anemia on Pregnancies Associated with SARS-CoV-2 Infection

Anemia is a very common occurrence during pregnancy, with important variations during each trimester. Anemia was also considered as a risk factor for severity and negative outcomes in patients with SARS-CoV-2 infection. As the COVID-19 pandemic poses a significant threat for pregnant women in terms of infection risk and access to care, we developed a study to determine the impact of nutritional supplementation for iron deficiency anemia in correlation with the status of SARS-CoV-2 infection. In a case-control design, we identified 446 pregnancies that matched our inclusion criteria from the hospital database. The cases and controls were stratified by SARS-CoV-2 infection history to observe the association between exposure and outcomes in both the mother and the newborn. A total of 95 pregnant women were diagnosed with COVID-19, having a significantly higher proportion of iron deficiency anemia. Low birth weight, prematurity, and lower APGAR scores were statistically more often occurring in the COVID-19 group. Birth weight showed a wide variation by nutritional supplementation during pregnancy. A daily combination of iron and folate was the optimal choice to normalize the weight at birth. The complete blood count and laboratory studies for iron deficiency showed significantly decreased levels in association with SARS-CoV-2 exposure. Puerperal infection, emergency c-section, and small for gestational age were strongly associated with anemia in patients with COVID-19. It is imperative to screen for iron and folate deficiency in pregnancies at risk for complications, and it is recommended to supplement the nutritional intake of these two to promote the normal development and growth of the newborn and avoid multiple complications during pregnancy in the COVID-19 pandemic setting.

Individual, household and national factors associated with iron, vitamin A and zinc deficiencies among children aged 6-59 months in Nepal

Iron, vitamin A and zinc deficiencies are the top three micronutrients contributing to disability-adjusted life years globally. The study assessed the factors associated with iron, vitamin A, and Zinc deficiencies among Nepalese children (n = 1709) aged 6-59 months using data from the 2016 Nepal National Micronutrient Status Survey. The following cut-off points were applied: iron deficiency [ferritin < 12 μg/L or soluble transferrin receptor (sTfR) > 8.3 mg/L], vitamin A deficiency (retinol-binding protein < 0.69 μmol/L) and zinc deficiency (serum zinc < 65 μg/dl for morning sample and <57 μg/dl for afternoon sample). We used multiple logistic regression adjusted for sampling weights and clustering to examine the predictors of micronutrient deficiencies. The prevalence of iron depletion (ferritin), tissue iron (sTfR), vitamin A and zinc deficiencies were 36.7%, 27.6%, 8.5% and 20.4%, respectively. Children were more likely to be iron deficient (ferritin) if aged 6-23 months, stunted, and in a middle-wealth quintile household. Vitamin A deficiency was associated with development region and was higher among children living in severe food-insecure households and those who did not consume fruits. Zinc deficiency was higher among children in rural areas and the poorest wealth quintile. The Government of Nepal should focus on addressing micronutrient deficiencies in the early years, with emphasis on improving food systems, promote healthy diets, among younger and stunted children and provide social cash transfer targeting high-risk development regions, poorest and food insecure households.

Iron status of exclusively breastfed low-birth-weight infants born to anemic mothers and effect of maternal iron supplementation for 3 versus 6 months: A randomized double-blind placebo control trial

BACKGROUND

The effect of maternal iron supplementation during lactation on the iron status of exclusively breastfed low-birth-weight (LBW) infants is not known.

OBJECTIVE

(1) To find out the number of LBW exclusively breastfed infants having hemoglobin < 10.5 g/dL at 6 months when mothers received iron. (2) To find out the proportion of anemic infants when mothers received iron for 3 and 6 months.

DESIGN

The Clinical Trials Registry, India (CTRI) registered trial (CTRI/2018/08/015516) double-blind randomized control trial participants: A total of 80 anemic mothers and exclusively breastfed LBW infants.

INTERVENTION

A total of 80 anemic mothers and exclusively breastfed infants, birth weight 1,500-2,499 g, randomized into two groups of 40 each. Mothers received daily iron for 3 months and placebo for the next 3 months in group A and iron for 6 months in group B. Iron profile of mothers and infants measured at recruitment and 6 months.

RESULTS

In total, 26.6% infants developed anemia till 6 months of age, and number of anemic infants were similar whether mothers received iron for 3 (n = 9) or 6 months (n = 11). Hemoglobin (12.89 + 0.46 vs. 12.44 + 0.48 g/dL; p < 0.001) and serum ferritin (27.45 + 7.60 vs. 18.94 + 5.36 ng/mL; p < 0.001) were significantly higher in infants at 6 months of age whose mothers received iron for 6 months in comparison to 3 months. Conclusion: totally, 26.6% exclusively breastfed infants developed anemia till 6 months of age when mothers took iron; number of anemic infants were not different if mothers received iron for 3 or 6 months. A significant increase was noted in serum ferritin with slightly higher hemoglobin of infants when mothers received iron for longer duration.

CLINICAL TRIAL REGISTRATION

[http://ctri.nic.in/Clinicaltrials/pubview.php], identifier [CTRI/2018/08/015516].

Effects of Daily Iron Supplementation on Motor Development and Brain Connectivity in Preterm Infants: A Diffusion Magnetic Resonance Study

Objectives: The aim of the study is to demonstrate the characteristic of motor development and MRI changes of related brain regions in preterm infants with different iron statuses and to determine whether the daily iron supplementation can promote motor development for preterm in early infancy. Methods: The 63 preterm infants were grouped into non-anemia with higher serum ferritin (NA-HF) group and anemia with lower serum ferritin (A-LF) group according to their lowest serum Hb level in the neonatal period as well as the sFer at 3 months old. Forty-nine participants underwent MRI scans and Infant Neurological International Battery (INFANIB) at their 3 months. At 6 months of corrected age, these infants received the assessment of Peabody Developmental Motor Scales (PDMS) after 2 mg/kg/day iron supplementation. Results: In total, 19 preterm infants were assigned to the NA-HF group while 44 preterm infants to the A-LF groups. The serum ferritin (sFer) level of the infants in A-LF group was lower than that in NA-HF group (44.0 ± 2.8 mg/L vs. 65.1 ± 2.8 mg/L, p < 0.05) and was with poorer scores of INFANIB (66.8 ± 0.9 vs. 64.4 ± 0.6, p < 0.05) at 3 months old. The structural connectivity between cerebellum and ipsilateral thalamus in the NA-HF group was significantly stronger than that in the A-LF group (n = 17, 109.76 ± 23.8 vs. n = 32, 70.4 ± 6.6, p < 0.05). The decreased brain structural connectivity was positively associated with the scores of PDMS (r = 0.347, p < 0.05). After 6 months of routine iron supplementation, no difference in Hb, MCV, MCHC, RDW, and sFer was detected between A-LF and NA-HF groups as well as the motor scores of PDMS-2 assessments. Conclusion: Iron status at early postnatal period of preterm infant is related to motor development and the enrichment of brain structural connectivity. The decrease in brain structural connectivity is related to the motor delay. After supplying 2 mg/kg of iron per day for 6 months, the differences in the iron status and motor ability between the A-LF and NA-HF groups were eliminated.

Iron Status of the Moderate and Late Preterm Infant: A Prospective Cohort Study

Guidelines on micronutrient supplementation in moderate to late preterm infants (MLP) are mostly extrapolated from those for smaller preterms, largely due to lack of systematic studies on physiological status in this special group of infants. Actual practices vary widely. We prospectively studied iron status by measurement of serum ferritin (SF) and haematological indices at 4 months corrected age in infants born between 32 and 36 weeks gestation (MLP), after they received 2 mg/kg/day oral iron from 6 weeks of postnatal age. Proportion of MLP having normal iron status (iron replete), i.e., neither iron deficiency (ID) nor iron excess was measured. ID anaemia, growth and development, risk factors for ID were also analysed. Of the 82 infants studied, 78% babies were late preterm. Seventy-four (90.3%) were iron replete (no deficiency or excess) at 4 months. High variability in SF levels (minimum of 9.8 to maximum of 252.2 μg/l) with median (IQR) of 57.45 μg/l (37.02-98.85) was noted in the entire cohort; and also within those who were iron deficient with median (IQR) of 17.50 μg/l (11.70-18.90). There was no difference in haematological indices of ID infants when compared to those with normal iron status. Inspite of oral iron supplementation with reasonable compliance, 8.5% MLP were iron deficient at 4 months corrected age. The high variability noted in SF levels could justify the need for monitoring iron status in this group of preterm infants. This could quintessentially aid individualization of iron supplementation advice.

Analysis of correlative risk factors for blood transfusion therapy for extremely low birth weight infants and extreme preterm infants

OBJECTIVE

To analyze the related risk factors in blood transfusions for extremely low birth weight infants and extreme preterm infants, and to explore the prevention strategy of anemia.

METHODS

A total of 60 infants with gestational age < 28 weeks or birth weight < 1000 g admitted to our hospital from January 2017 to December 2020 were retrospectively analyzed. The infants with a birth weight of less than 1000 g were divided into the blood transfusion group and the non-blood transfusion group according to whether they received a blood transfusion. The general health situation, disease occurrence and treatment measures during hospitalization were compared between the two groups, and the risk factors of blood transfusion were analyzed.

RESULTS

There were significant differences in maternal anemia during pregnancy, birth weight, gestational age, hemoglobin and hematocrit at birth, blood collection within 2 weeks after birth, length of hospital stay, bronchopulmonary dysplasia and patent ductus arteriosus between the transfusion group and the non-transfusion group (P < 0.05). Multivariate logistic regression analysis and ROC curve analysis showed that the younger the gestational age (OR=0.385, 95% CI: 0.212~0.705, P=0.002), the lower the birth weight (OR=1.004, 95% CI: 0.967~0.998, P=0.001), the longer the hospitalization time (OR=2.178, 95% CI: 1.172~4.049, P=0.014) and a larger blood collection within 2 weeks after birth (OR=1.269, 95% CI: 1.084~1.489, P=0.003) would induce higher the blood transfusion rates.

CONCLUSION

The transfusion indications of extremely low birth weight infants and extreme preterm infants are affected by many factors, among which gestational age, length of hospital stay, blood collection within 2 weeks after birth and birth weight are independent predictors of transfusion. Blood transfusion in extremely low birth weight infants and extreme preterm infants is associated with an increased risk of apnea, neonatal respiratory distress syndrome, bronchopulmonary dysplasia and patent ductus arteriosus.

The critical roles of iron during the journey from fetus to adolescent: Developmental aspects of iron homeostasis

Iron is indispensable for human life. However, it is also potentially toxic, since it catalyzes the formation of harmful oxidative radicals in unbound form and may facilitate pathogen growth. Therefore, iron homeostasis needs to be tightly regulated. Rapid growth and development require large amounts of iron, while (especially young) children are vulnerable to infections with iron-dependent pathogens due to an immature immune system. Moreover, unbalanced iron status early in life may have effects on the nervous system, immune system and gut microbiota that persist into adulthood. In this narrative review, we assess the critical roles of iron for growth and development and elaborate how the body adapts to physiologically high iron demands during the journey from fetus to adolescent. As a first step towards the development of clinical guidelines for the management of iron disorders in children, we summarize the unmet needs regarding the developmental aspects of iron homeostasis.

Effect of Daily Iron Supplementation on Infantile Iron Homeostasis in Preterm Infants

Objective: The aim of this study was to investigate the effects of unified iron supplementation and identify the factors related to the iron homeostasis among preterm infants. Method: A total of 250 preterm infants were divided into neonatal anemic (NA, n = 154) and non-neonatal anemic group (NNA, n = 96). Iron supplements at a dose of 2 mg/kg per day were given from 40 weeks' gestational age to 6 months. Iron status parameters were measured at 3 and 6 months, respectively. Prevalence of iron deficiency (ID) and iron deficiency anemia (IDA), and the correlated factors were analyzed. Growth and side-effects were monitored. Results: There were no significant differences for the prevalence of ID or IDA between the two groups. Multivariate regression analyses showed that higher Hb at birth and early treatment of blood transfusion reduced the risk of ID/IDA at 3 months (all p < 0.05); while higher level of Hb at 3 months (p = 0.004) and formula feeding reduced the occurrence of ID/IDA at 6 months (p < 0.05); males had a 3.35 times higher risk to develop ID/IDA than girls (p = 0.021). No differences in growth and side effects were found. Conclusion: A daily dose of 2 mg/kg iron supplement is beneficial to maintain iron homeostasis in majority preterm infants within 6 months regardless of their neonatal anemia history. Under the routine iron supplementation, Hb level at birth and at 3 months, early treatment of blood transfusion, gender and feeding patterns are the major factors affecting the prevalence of ID/IDA among preterm infants in infancy.

Iron deficiency in infancy: current insights

PURPOSE OF REVIEW

Iron deficiency is the most common micronutrient deficiency and infants are at particular risk. The purpose of this review is to summarize recent studies that explored the metabolism of iron in infants as well as the risks and benefits of iron supplementation in different populations.

RECENT FINDINGS

The ability of infants to regulate iron homeostasis is not fully known but most likely different from adults. Reducing iron deficiency has beneficial effects on neurodevelopment but iron overload may have adverse functional effects including diarrhea and even poor neurodevelopment. Recent studies have confirmed benefits of delayed cord clamping and supplementation of infants in risk groups while iron supplementation to pregnant women has shown limited effect in the offspring with regard to iron status and neurodevelopment. Further support is given to the recommendation that exclusive breast feeding, without supplementation, is safe for normal birth weight infants until 6 months whereafter an iron-rich diet should be given.

SUMMARY

Iron deficiency negatively impacts global health but efforts to identify optimal interventions are progressing. Yet, questions remain, particularly regarding long-term risks, benefits and optimal interventions for low birth weight infants as well as the level of iron fortification in infant formula.

Adherence to iron and folic acid supplementation during pregnancy among postnatal mothers seeking maternal and child healthcare at Kakamega level 5 hospital in Kenya: a cross-sectional study

Background: Maternal anaemia is a public health problem worldwide, and its aetiology is linked to iron deficiency. The high nutrient demand during pregnancy exacerbates the condition. To meet the increased nutritional demand, supplementation of iron and folic acid (IFA) is key. The supplements are provided freely to pregnant women during antenatal visits at public health facilities, however, their uptake and adherence in Kenya remain unacceptably low. Methods: A hospital-based cross-sectional study involving 241 postnatal mothers seeking maternal and child healthcare (MCH) care at Kakamega level 5 hospital was conducted. Both quantitative and qualitative data were collected. Quantitative data were collected from 241 eligible postnatal mothers, while qualitative data were obtained through key informant interviews with community health volunteers and healthcare providers. Results: There was a moderate adherence to IFA supplementation (60.6%) during pregnancy among postnatal mothers seeking MCH care at Kakamega level 5 hospital. Some of the reasons for non-adherence stated by the respondents included; IFA related side effects (41.3%), forgetfulness (37.3%) and bad smell of the IFA supplements (10.3%). Higher IFA adherence was noted among the primigravida participants (OR=2.704; 95% CI: 1.262, 5.793; p=0.010) compared to multigravida participants, and those with a higher knowledge level of anaemia (OR=3.215; 95% CI: 1.346, 7.68; p=0.009) compared to their counterparts with low anaemia knowledge. Other factors that showed correlation with IFA adherence were: IFA education, pregnancy counselling before conception and the number of antenatal care visits attained. Conclusion: There is a moderate adherence to IFA supplementation during pregnancy among mothers seeking MCH at Kakamega level 5 hospital. The greatest impediments of IFA compliance during pregnancy are IFA side effects, forgetfulness and the bad smell of the IFA tablets. Therefore, providing IFA education to pregnant mothers incorporated with probable ways of managing the IFA side effects would contribute to IFA supplementation adherence.

Longitudinal Study Depicting Differences in Complementary Feeding and Anthropometric Parameters in Late Preterm Infants up to 2 Years of Age

Ensuring the nutritional demands of preterm (PT) infants during complementary feeding could contribute significantly to the infants’ long-term health and development. However, the dietary guidelines for complementary feeding in PT are scarce. Thus, describing dietary intake and identifying nutritional targets for these infants could be of great interest. The aim of this study is to assess the food intake and anthropometric parameters in a Mediterranean infant cohort from 6 to 24 months and to identify nutritional targets especially focused on late preterm infants. This is a longitudinal prospective study analyzing information from administered questionnaires about general characteristics and food frequency consumption in 115 infants (20 PT (32 to 36 gestational weeks), 95 full-term (FT)) at 6, 12 and 24 months of age. Results show that the differences in the prevalence of underweight observed in PT infants vs. FT infants are maintained for up to 6 months of age but disappear at 12 and 24 months. The age of inclusion of new foods and the average intake of the main food groups was not different from that of FTs. Although protein intake at 6 months was directly correlated with weight gain and growth in FT, these associations were not observed in PT. At the nutritional level, the low intake of vitamin D in preterm infants is noteworthy. These findings may be useful when designing new intervention strategies for this population group.

Infantile Iron Deficiency Affects Brain Development in Monkeys Even After Treatment of Anemia

A high percent of oxidative energy metabolism is needed to support brain growth during infancy. Unhealthy diets and limited nutrition, as well as other environmental insults, can compromise these essential developmental processes. In particular, iron deficiency anemia (IDA) has been found to undermine both normal brain growth and neurobehavioral development. Even moderate ID may affect neural maturation because when iron is limited, it is prioritized first to red blood cells over the brain. A primate model was used to investigate the neural effects of a transient ID and if deficits would persist after iron treatment. The large size and postnatal growth of the monkey brain makes the findings relevant to the metabolic and iron needs of human infants, and initiating treatment upon diagnosis of anemia reflects clinical practice. Specifically, this analysis determined whether brain maturation would still be compromised at 1 year of age if an anemic infant was treated promptly once diagnosed. The hematology and iron status of 41 infant rhesus monkeys was screened at 2-month intervals. Fifteen became ID; 12 met clinical criteria for anemia and were administered iron dextran and B vitamins for 1-2 months. MRI scans were acquired at 1 year. The volumetric and diffusion tensor imaging (DTI) measures from the ID infants were compared with monkeys who remained continuously iron sufficient (IS). A prior history of ID was associated with smaller total brain volumes, driven primarily by significantly less total gray matter (GM) and smaller GM volumes in several cortical regions. At the macrostructual level, the effect on white matter volumes (WM) was not as overt. However, DTI analyses of WM microstructure indicated two later-maturating anterior tracts were negatively affected. The findings reaffirm the importance of iron for normal brain development. Given that brain differences were still evident even after iron treatment and following recovery of iron-dependent hematological indices, the results highlight the importance of early detection and preemptive supplementation to limit the neural consequences of ID.

Iron deficiency

Iron deficiency is one of the leading contributors to the global burden of disease, and particularly affects children, premenopausal women, and people in low-income and middle-income countries. Anaemia is one of many consequences of iron deficiency, and clinical and functional impairments can occur in the absence of anaemia. Iron deprivation from erythroblasts and other tissues occurs when total body stores of iron are low or when inflammation causes withholding of iron from the plasma, particularly through the action of hepcidin, the main regulator of systemic iron homoeostasis. Oral iron therapy is the first line of treatment in most cases. Hepcidin upregulation by oral iron supplementation limits the absorption efficiency of high-dose oral iron supplementation, and of oral iron during inflammation. Modern parenteral iron formulations have substantially altered iron treatment and enable rapid, safe total-dose iron replacement. An underlying cause should be sought in all patients presenting with iron deficiency: screening for coeliac disease should be considered routinely, and endoscopic investigation to exclude bleeding gastrointestinal lesions is warranted in men and postmenopausal women presenting with iron deficiency anaemia. Iron supplementation programmes in low-income countries comprise part of the solution to meeting WHO Global Nutrition Targets.

Beyond the Mind-Serum Trace Element Levels in Schizophrenic Patients: A Systematic Review

The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.

Essential and toxic elements in human milk concentrate with human milk lyophilizate: A preclinical study

Concentrated human milk (HM-concentrate) can be obtained from the simple and inexpensive method of donated breast milk direct lyophilization. A previous study reported that HM-concentrate contains the adequate amount of main macro- and micronutrients for use as a nutritional resource for preterm infants with very low birth weight admitted to neonatal intensive care units. However, further details need to be elucidated about HM-concentrate composition, particularly its content of essential and potentially toxic trace elements. Therefore, this study aimed to determine the concentration of essential and toxic elements in human milk considered baseline (HM-baseline) and HM-concentrate, as well as to quantify changes in concentration of these elements after the HM concentration process. The concentration of Aluminum, Arsenic, Cadmium, Chromium, Iron, Mercury, Manganese, Nickel, Lead, Selenium, Tin, and Thallium was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Moreover, Bayesian linear mixed effect models were applied to estimate the mean difference between HM-baseline and HM-concentrate samples. After comparison (HM-concentrate versus HM-baseline), a significant increase in concentration was observed only for Manganese (0.80 μg/L; 95% CrI [0.16; 1.43]) and Selenium (6.74 μg/L; 95% CrI [4.66; 8.86]), while Lead concentration (-6.13 μg/L; 95% CrI [-8.63; -3.61]) decreased. This study provides latest and reliable information about HM composition. After milk concentration by lyophilization, there was a significant increase only in the essential elements Manganese and Selenium. The essential micronutrient content in HM-concentrate was similar or higher than that in preterm mothers' milk, which suggests it is viable for nutritional support of preterm infants. In addition, the low concentrations of potentially toxic elements in HM-concentrate indicates that it is safe for consumption by premature newborns.

Iron Homeostasis Disruption and Oxidative Stress in Preterm Newborns

Iron is an essential micronutrient for early development, being involved in several cellular processes and playing a significant role in neurodevelopment. Prematurity may impact on iron homeostasis in different ways. On the one hand, more than half of preterm infants develop iron deficiency (ID)/ID anemia (IDA), due to the shorter duration of pregnancy, early postnatal growth, insufficient erythropoiesis, and phlebotomy losses. On the other hand, the sickest patients are exposed to erythrocytes transfusions, increasing the risk of iron overload under conditions of impaired antioxidant capacity. Prevention of iron shortage through placental transfusion, blood-sparing practices for laboratory assessments, and iron supplementation is the first frontier in the management of anemia in preterm infants. The American Academy of Pediatrics recommends the administration of 2 mg/kg/day of oral elemental iron to human milk-fed preterm infants from one month of age to prevent ID. To date, there is no consensus on the type of iron preparations, dosages, or starting time of administration to meet optimal cost-efficacy and safety measures. We will identify the main determinants of iron homeostasis in premature infants, elaborate on iron-mediated redox unbalance, and highlight areas for further research to tailor the management of iron metabolism.

Nutritional Assessment in Preterm Infants: A Practical Approach in the NICU

A practical approach for nutritional assessment in preterm infants under intensive care, based on anthropometric measurements and commonly used biochemical markers, is suggested. The choice of anthropometric charts depends on the purpose: Fenton 2013 charts to assess intrauterine growth, an online growth calculator to monitor intra-hospital weight gain, and Intergrowth-21st standards to monitor growth after discharge. Body weight, though largely used, does not inform on body compartment sizes. Mid-upper arm circumference estimates body adiposity and is easy to measure. Body length reflects skeletal growth and fat-free mass, provided it is accurately measured. Head circumference indicates brain growth. Skinfolds estimate reasonably body fat. Weight-to-length ratio, body mass index, and ponderal index can assess body proportionality at birth. These and other derived indices, such as the mid-upper arm circumference to head circumference ratio, could be proxies of body composition but need validation. Low blood urea nitrogen may indicate insufficient protein intake. Prealbumin and retinol binding protein are good markers of current protein status, but they may be affected by non-nutritional factors. The combination of a high serum alkaline phosphatase level and a low serum phosphate level is the best biochemical marker for the early detection of metabolic bone disease.