Iron status of children in southern Sweden: effects of cow's milk and follow-on formula

Research on commercial milk formulas for young children: A scoping review

A scoping review of publications about commercial milk formulas intended for or consumed by children 12-36 months (CMF 12-36) was conducted. This review aimed to comprehensively map the existing literature, identify key concepts in the field and understand its evolution through time. A total of 3329 articles were screened and 220 were included, published between 1986 and 2024. Most works were published after 2016 (70.0%) and in high-income countries (71.8%). Original studies were the vast majority (81.8%) of publications. Most publications dealt with feeding practices or analysed the composition and/or contamination of specific products (44.1% and 35.9%), but since the late 2000s, publications about marketing, policy, legislation, and consumer perception started to appear. Most published works (65.5%) did not focus exclusively on CMF 12-36 and included formulas for other demographics or other foods. About half of the works (55.5%) did not consider CMF 12-36 to be a breast milk substitute. We found 81 distinct product denominations used to refer to CMF 12-36, Growing Up Milk was the most common (25.9%). CMF industry was involved in 41.8% of all analysed works, and industry participation and funding were not always clearly informed (22.5% lacked a conflict of interest statement, and 25.5% did not present any information about funding). In the last decade, publications about CMF 12-36 have increased in volume and diversified in scope and subject matter. CMF-industry participation has always been and still is present in the field, so possible vested interests should be taken into account when appreciating the literature.

Toddler milk: a scoping review of research on consumption, perceptions, and marketing practices

Toddler milk is an ultra-processed beverage consisting primarily of powdered milk, caloric sweeteners, and vegetable oil. Pediatric health authorities do not support the use of toddler milk, and emerging evidence suggests that toddler-milk marketing practices may mislead consumers. However, studies have not synthesized the extent of toddler-milk marketing practices or how these practices affect parents' decisions about whether to serve toddler milk. We aimed to summarize the literature about toddler milk to identify what is known about: (1) parents' toddler-milk purchasing and feeding behaviors, (2) toddler-milk marketing, and (3) how marketing practices influence parents' beliefs and perceptions about toddler milk. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), we systematically searched 8 databases (PubMed, APA PsycINFO, Scopus, Cochrane Central, Embase, CINAHL, Communication & Mass Media Complete, and Business Source Premier). We identified 45 articles about toddler milk. Studies were conducted in 25 countries across 6 continents. Five types of findings emerged: (1) consumption and feeding behaviors, (2) demographic correlates of toddler-milk purchasing and consumption, (3) misperceptions and beliefs, (4) increased sales, and (5) increased marketing and responses to marketing. The included articles suggested that toddler-milk sales are growing rapidly worldwide. Findings also revealed that toddler-milk packages (eg, labels, branding) resemble infant formula packages and that toddler-milk marketing practices may indirectly advertise infant formula. Purchasing, serving, and consumption of toddler milk were higher in Black and Hispanic populations than in non-Hispanic White populations, and parents with higher educational attainment and income were more likely to offer toddler milk to their children. Findings suggest a need for policies to prevent cross-marketing of toddler milk and infant formula, reduce provision of toddler milk to infants and toddlers, and prevent caregivers from being misled about toddler-milk healthfulness.

Iron Nutrition of Pre-Schoolers in High-Income Countries: A Review

Pre-schoolers are vulnerable to iron deficiency, which, in high-resource countries, is mainly caused by suboptimal or poorly absorbable iron intakes. This review examines the prevalence of inadequate iron intakes and status, and the non-dietary factors associated with these, among children aged between 2 and 5 years within high-income countries. It then considers the quality of the pre-schooler diet in terms of dietary factors, dietary patterns, and iron intakes. Additionally, it discusses the assessment of iron bioavailability and examines the various methods used to estimate the amount of absorbable iron in pre-schooler diets. Knowledge of the adequacy of iron intakes and bioavailability of iron intakes, and dietary patterns associated with iron intakes can facilitate the design and implementation of effectively targeted community-based intervention studies to improve iron intakes and iron bioavailability to minimise the risk of iron deficiency.

Food consumption, nutritional intakes and the role of milk formulas in nutrient adequacy among young children from birth to 2 years living in urban Algeria

OBJECTIVE

Undernutrition, stunted growth and obesity remain a concern in Algeria. Currently, limited data are available on nutrient intakes among children. Our study aimed to describe food and nutrient intakes and the role of milk formulas among Algerian children.

DESIGN

Dietary intakes were collected using a 4-d interview-based survey for children aged 0-24 months, living in urban areas in Algeria in 2019.

SETTING

Food consumptions were described. For children aged 6-24 months, nutrient intakes and adequacy were estimated. Modelling was used to estimate the nutritional impact of substituting cow's milk for age-appropriate infant formulas (IF).

PARTICIPANTS

Totally, 446 children aged 0-24 months.

RESULTS

Before 6 months, 91·6 % of infants were breastfed. Breastmilk was also the main milk consumed between 6 and 12 months, whereas cow's milk predominated after 12 months. In children aged 6-24 months, nutrient adequacy prevalence was above 75 % for the majority of nutrients. However, less than 30 % of the children had adequate intakes for total fats, Fe and vitamin D. Simulated substitution of cow's milk for IF led to improved adequacy for proteins, Fe, and vitamins D and E.

CONCLUSIONS

Our study showed that breast-feeding rates were high until 6 months, then declined with age. Consumed foods allowed Algerian children aged 6-24 months to meet most of their nutritional needs, but inadequate intakes were reported for some key nutrients. Our modelling suggested that milk formulas may help to improve nutrient adequacy among non-breastfed infants. Other dietary changes could also be further investigated to enable children to meet all nutritional recommendations.

Effect of consumption of animal milk compared to infant formula for non-breastfed/mixed-fed infants 6-11 months of age: a systematic review (protocol)

INTRODUCTION

Prevalence rates of breastfeeding remain low even though the World Health Organization (WHO) and the American Academy of Pediatrics recommend exclusive breast feeding for the first 6 months of life in combination with appropriate complementary feeding beyond six 6 months of age. There have been several studies that address the implication of drinking animal milk and/or infant formula on children's health and development when breast feeding is not offered during the first year of life. Vast improvements have been made in infant formula design, which may increase its benefits compared with animal's milk. The objective of this review is therefore to synthesise the most recent evidence on the effects of the consumption of animal milk compared with infant formula in non-breastfed or mixed breastfed infants aged 6-11 months.

METHODS AND ANALYSIS

We will conduct a systematic review and meta-analysis of studies that assessed the effect of animal milk compared with formula or mixed-fed (breastmilk and formula) on infants aged 6-11 months. The primary outcomes of interest include anaemia, gastrointestinal blood loss, weight for age, height for age and weight for height. We will include randomised and non-randomised studies with a control group. We will use the Cochrane risk of bias tools to assess the risk of bias. We will use meta-analysis to pool findings if the identified studies are conceptually homogenous and data are available from more than one study. We will assess the overall quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

ETHICS AND DISSEMINATION

This is a systematic review, so no patients will be directly involved in the design or development of this study. The findings from this systematic review will be disseminated to relevant patient populations and caregivers and will guide the WHO's recommendations on formula consumption versus animal milk in infants aged 6-11 months.

TRIAL REGISTRATION NUMBER

CRD42020210925.

A comparison of the effect of a Growing Up Milk - Lite (GUMLi) v. cows' milk on longitudinal dietary patterns and nutrient intakes in children aged 12-23 months: the GUMLi randomised controlled trial

The second year of life is a period of nutritional vulnerability. We aimed to investigate the dietary patterns and nutrient intakes from 1 to 2 years of age during the 12-month follow-up period of the Growing Up Milk - Lite (GUMLi) trial. The GUMLi trial was a multi-centre, double-blinded, randomised controlled trial of 160 healthy 1-year-old children in Auckland, New Zealand and Brisbane, Australia. Dietary intakes were collected at baseline, 3, 6, 9 and 12 months post-randomisation, using a validated FFQ. Dietary patterns were identified using principal component analysis of the frequency of food item consumption per d. The effect of the intervention on dietary patterns and intake of eleven nutrients over the duration of the trial were investigated using random effects mixed models. A total of three dietary patterns were identified at baseline: 'junk/snack foods', 'healthy/guideline foods' and 'breast milk/formula'. A significant group difference was observed in 'breast milk/formula' dietary pattern z scores at 12 months post-randomisation, where those in the GUMLi group loaded more positively on this pattern, suggesting more frequent consumption of breast milk. No difference was seen in the other two dietary patterns. Significant intervention effects were seen on nutrient intake between the GUMLi (intervention) and cows' milk (control) groups, with lower protein and vitamin B12, and higher Fe, vitamin D, vitamin C and Zn intake in the GUMLi (intervention) group. The consumption of GUMLi did not affect dietary patterns, however, GUMLi participants had lower protein intake and higher Fe, vitamins D and C and Zn intake at 2 years of age.

A Comparative Analysis of the Contents Of Iron, Zinc, Copper, Manganese, and Calcium in the Collective Diet Of Preschool Children in the Northwestern Region of Bosnia

Researches conducted worldwide indicate a frequent deficiency in mineral matters. Due to the increased need during the period of accelerated growth and development, children belong to the group that is exposed to the highest risk of mineral matter deficiency. Our objectives were to determine the iron, zinc, copper, manganese, and calcium intake in the collective diet of the preschool population in the in the northwestern region of Bosnia- in the Republic of Srpska and to estimate the adequacy of the application of the international food composition tables for nutrition planning relating to mineral matters. Samples of food intended for children's diet were collected in the preschool institution "Radost" (a kindergarten), in the city of Prijedor. In daily portions, Fe, Zn, Cu, Mn, and Ca contents were determined by flame atomic absorption spectrophotometry. Contents of mineral matters in daily meals were also calculated by the food composition tables. An average daily meal contained 2.86 mg of Fe, 1.71 mg of Zn, 0.19 mg of Cu, 0.21 mg of Mn, and 83.5 mg of Ca. With calculation method, contents of all minerals are significantly higher than the experimental data for all used food composition tables. The obtained results indicate a significant deficiency in mineral matters in the collective diet of the preschool population in the Republic of Srpska, a certain non-compliance with the applicable recommendations, and also suggest a need to create food composition tables for food being consumed in our region.

Iron requirements of infants and toddlers

Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group because their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of ID anemia (IDA) include low birth weight, high cow's-milk intake, low intake of iron-rich complementary foods, low socioeconomic status, and immigrant status. The aim of this position paper was to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight. There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of ID. There is insufficient evidence to support general iron supplementation of healthy European infants and toddlers of normal birth weight. Formula-fed infants up to 6 months of age should receive iron-fortified infant formula, with an iron content of 4 to 8 mg/L (0.6-1.2 mg(-1) · kg(-1) · day(-1)). Marginally low-birth-weight infants (2000-2500 g) should receive iron supplements of 1-2 mg(-1) · kg(-1) · day(-1). Follow-on formulas should be iron-fortified; however, there is not enough evidence to determine the optimal iron concentration in follow-on formula. From the age of 6 months, all infants and toddlers should receive iron-rich (complementary) foods, including meat products and/or iron-fortified foods. Unmodified cow's milk should not be fed as the main milk drink to infants before the age of 12 months and intake should be limited to <500 mL/day in toddlers. It is important to ensure that this dietary advice reaches high-risk groups such as socioeconomically disadvantaged families and immigrant families.

Health effects of different dietary iron intakes: a systematic literature review for the 5th Nordic Nutrition Recommendations

BACKGROUND

The present literature review is part of the NNR5 project with the aim of reviewing and updating the scientific basis of the 4th edition of the Nordic Nutrition Recommendations (NNR) issued in 2004.

OBJECTIVE

The objective of this systematic literature review was to assess the health effects of different intakes of iron, at different life stages (infants, children, adolescents, adults, elderly, and during pregnancy and lactation), in order to estimate the requirement for adequate growth, development, and maintenance of health.

METHODS

The initial literature search resulted in 1,076 abstracts. Out of those, 276 papers were identified as potentially relevant. Of those, 49 were considered relevant and were quality assessed (A, B, or C). An additional search on iron and diabetes yielded six articles that were quality assessed. Thus, a total of 55 articles were evaluated. The grade of evidence was classified as convincing (grade 1), probable (grade 2), suggestive (grade 3), and inconclusive (grade 4).

RESULTS

There is suggestive evidence that prevention or treatment of iron deficiency (ID) and iron deficiency anemia (IDA) improves cognitive, motoric, and behavioral development in young children, and that treatment of IDA improves attention and concentration in school children and adult women. There is insufficient evidence to show negative health effects of iron intakes in doses suggested by the NNR 4. There is insufficient evidence to suggest that normal birth weight, healthy, exclusively breast-fed infants need additional dietary iron before 6 months of life in the Nordic countries. An iron concentration of 4-8 mg/L in infant formulas seems to be safe and effective for normal birth weight infants. There is probable evidence that iron supplements (1-2 mg/kg/day) given up to 6 months of age to infants with low birth weight (<2,500 g) prevents IDA and possibly reduce the risk of behavioral problems later on. There is probable evidence that ID and IDA in pregnant women can be effectively prevented by iron supplementation at a dose of 40 mg/day from week 18-20 of gestation. There is probable evidence that a high intake of heme iron, but not total dietary, non-heme or supplemental iron, is associated with increased risk of type 2 diabetes (T2D) and gestational diabetes.

CONCLUSIONS

Overall, the evidence does not support a change of the iron intakes recommended in the NNR 4. However, one could consider adding recommendations for infants below 6 months of age, low birth weight infants and pregnant women.

Consumption of cow's milk as a cause of iron deficiency in infants and toddlers

Consumption of cow's milk (CM) by infants and toddlers has adverse effects on their iron stores, a finding that has been well documented in many localities. Several mechanisms have been identified that may contribute to iron deficiency in this young population group. The most important of these is probably the low iron content of CM, which makes it difficult for infants to obtain the amounts of iron needed for growth. A second mechanism is the occult intestinal blood loss associated with CM consumption during infancy, a condition that affects about 40% of otherwise healthy infants. Loss of iron in the form of blood diminishes with age and ceases after the age of 1 year. A third mechanism is the inhibition of non-heme iron absorption by calcium and casein, both of which are present in high amounts in CM. Fortification of CM with iron, as practiced in some countries, can protect infants and toddlers against CM's negative effects on iron status. Consumption of CM produces a high renal solute load, which leads to a higher urine solute concentration than consumption of breast milk or formula, thereby narrowing the margin of safety during dehydrating events, such as diarrhea. The high protein intake from CM may also place infants at increased risk of obesity in later childhood. It is thus recommended that unmodified, unfortified CM not be fed to infants and that it be fed to toddlers in modest amounts only.

Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial

OBJECTIVE

To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on infant iron status at 4 months of age in a European setting.

DESIGN

Randomised controlled trial.

SETTING

Swedish county hospital.

PARTICIPANTS

400 full term infants born after a low risk pregnancy.

INTERVENTION

Infants were randomised to delayed umbilical cord clamping (≥ 180 seconds after delivery) or early clamping (≤ 10 seconds after delivery).

MAIN OUTCOME MEASURES

Haemoglobin and iron status at 4 months of age with the power estimate based on serum ferritin levels. Secondary outcomes included neonatal anaemia, early respiratory symptoms, polycythaemia, and need for phototherapy.

RESULTS

At 4 months of age, infants showed no significant differences in haemoglobin concentration between the groups, but infants subjected to delayed cord clamping had 45% (95% confidence interval 23% to 71%) higher mean ferritin concentration (117 μg/L v 81 μg/L, P < 0.001) and a lower prevalence of iron deficiency (1 (0.6%) v 10 (5.7%), P = 0.01, relative risk reduction 0.90; number needed to treat = 20 (17 to 67)). As for secondary outcomes, the delayed cord clamping group had lower prevalence of neonatal anaemia at 2 days of age (2 (1.2%) v 10 (6.3%), P = 0.02, relative risk reduction 0.80, number needed to treat 20 (15 to 111)). There were no significant differences between groups in postnatal respiratory symptoms, polycythaemia, or hyperbilirubinaemia requiring phototherapy.

CONCLUSIONS

Delayed cord clamping, compared with early clamping, resulted in improved iron status and reduced prevalence of iron deficiency at 4 months of age, and reduced prevalence of neonatal anaemia, without demonstrable adverse effects. As iron deficiency in infants even without anaemia has been associated with impaired development, delayed cord clamping seems to benefit full term infants even in regions with a relatively low prevalence of iron deficiency anaemia. Trial registration Clinical Trials NCT01245296.

Food-based strategies improve iron status in toddlers: a randomized controlled trial12

BACKGROUND

Nonanemic iron deficiency is common in toddlers in developed countries. Food-based strategies are safe methods to control and prevent mild micronutrient deficiencies.

OBJECTIVE

Our objective was to determine the efficacy of an increased intake of red meat, or the consumption of iron-fortified milk, in improvement of iron status in toddlers at a population level.

DESIGN

In this 20-wk randomized placebo-controlled trial, 225 healthy nonanemic 12-20-mo-old children were assigned to 1 of 3 groups: red meat (toddlers encouraged to consume approximately 2.6 mg iron from red meat dishes daily), fortified milk [toddlers' regular milk replaced with iron-fortified (1.5 mg iron/100 g prepared milk) cow milk], or control [toddlers' regular milk replaced with nonfortified (0.01 mg iron/100 g prepared milk) cow milk]. Blood samples were collected at baseline and at 20 wk for hemoglobin, serum ferritin, serum transferrin receptor, and C-reactive protein. The prevalence of suboptimal iron status (ie, depleted iron stores, iron-deficient erythropoiesis, and iron deficiency anemia) was determined, and body iron was calculated.

RESULTS

No intervention effects were shown on the prevalence of suboptimal iron status. Serum ferritin increased by 44% (95% CI: 14%, 82%; P = 0.002) in the fortified milk group, did not change (+10%) in the red meat group (95% CI: -7%, 30%; P = 0.241), and tended to decrease (-14%) in the control group (95% CI: -27%, 1%; P = 0.063). By 20 wk, in comparison with the control group, serum ferritin and body iron were significantly higher in the fortified milk group (both P < 0.001), and serum ferritin was significantly higher in the red meat group (P = 0.033).

CONCLUSIONS

Consumption of iron-fortified milk can increase iron stores in healthy nonanemic toddlers, whereas increased intakes of red meat can prevent their decline. This trial was registered at actr.org.au as ACTRN12605000487617.

Excessive Cow's Milk Consumption and Iron Deficiency in Toddlers

Elimination of iron deficiency and iron deficiency anemia in children is a crucial public health concern because these conditions have been linked to cognitive and behavioral deficits. In the infant age group, great strides have been made to reduce iron deficiency and iron deficiency anemia significantly. However, similar progress has not yet been made with toddlers. Cow's milk consumption has long been associated with iron deficiency and iron deficiency anemia in children. Because cow's milk is a staple in the diet of most toddlers, they are at particular risk for these conditions. Two unusual presentations of anemia in toddlers caused by excessive cow's milk consumption are described: one in a child with congestive heart failure, the other in a child with profound eosinophilia. The role of cow's milk in iron deficiency and iron deficiency anemia is also examined.

Predictors of iron status in well-nourished 4-y-old children

BACKGROUND

Iron status in childhood is influenced by diet. Other factors affecting iron status at that age are unclear.

OBJECTIVES

The objectives of the study were to evaluate iron status in 4-y-old children, to track that status from infancy to childhood, and to examine the associations of iron status with dietary factors, growth, and heredity.

DESIGN

This study consisted of a longitudinal follow-up at age 4 y of children (n = 127) from the cohort of a study that began at age 6 mo. Blood samples and anthropometry were assessed in both children and their parents; food records were collected from children only.

RESULTS

Dietary intake was not significantly correlated with hemoglobin concentrations, whereas the consumption of meat products had a positive effect on serum ferritin concentrations and mean corpuscular volume in boys (P = 0.015 and 0.04, respectively). The prevalences of anemia and iron deficiency were low, affecting 2 (1.8%) and 3 (2.8%) children, respectively; no child had iron deficiency anemia. There was significant within-subject tracking of hemoglobin and mean corpuscular volume from age 6 mo to 4 y. The mother's but not the father's hemoglobin correlated with the child's hemoglobin over time.

CONCLUSIONS

Food choices had little effect on iron status. Hemoglobin concentrations and mean corpuscular volume were tracked from infancy to childhood. In healthy, well-nourished children with a low prevalence of iron deficiency, the mother's hemoglobin was significantly associated with that of her child, but the underlying mechanism is unclear.

Iron status in 2-year-old Icelandic children and associations with dietary intake and growth

OBJECTIVE

To investigate the effects of food and nutrient intake at 2 y and growth from birth on iron status at 2 y in a population with high birth weight.

DESIGN

In a cross-sectional study, children's food consumption and body size measurements were recorded and blood samples taken. Weighed 3-day food records were used to analyse food and nutrient intake.

SETTING

Children were recruited from across Iceland from the Icelandic National Registry by the University of Iceland, Computing Services. The children in the sample were born over a 1-y period.

SUBJECTS

Parents of randomly selected 2-year-old children (n=130) were contacted, and 72% (n=94) participated. Blood samples were analysed in 76% (n=71) of participating children.

RESULTS

In total, 9% of the children were iron-deficient (serum ferritin (SF)<12 microg/l and mean corpuscular volume (MCV) <74 fl) and 1.4% were also anaemic (Hb<105 g/l), while 27% of children were iron-depleted (SF<12 microg/l). Iron status indices were negatively associated with cow's milk consumption. Half of children consuming>500 g cow's milk/day (n=10) were iron-deficient, while one child in 58 consuming<500 g cow's milk/day had iron deficiency (P<0.001). In multiple regression analyses, also biscuits and crackers consumption was positively associated with MCV. Weight gain from birth to 2 y was negatively associated with SF (adjusted R(2)=0.15; P=0.002; n=58). Iron-depleted children were heavier than children not iron-depleted (14.7+/-1.3 vs 13.8+/-1.7 kg; P=0.043), had higher BMI (17.7+/-1.5 vs 16.7+/-1.4 kg/m(2); P=0.028) and gained more weight from birth (11.2+/-1.3 vs. 10.0+/-1.6 kg; P=0.011).

CONCLUSIONS

The results suggest that cow's milk consumption above 500 g/day should be avoided at the age of 2 y for better iron status. Iron depletion at 2 y is associated with faster growth from birth.

Iron deficiency and risk factors for lower iron stores in 6–24-month-old New Zealanders

OBJECTIVES

To determine the prevalence of biochemical iron deficiency and identify factors associated with ferritin levels among 6-24-month-old urban South Island New Zealand children.

DESIGN

Cross-sectional survey conducted from May 1998 to March 1999.

SETTING

The cities of Christchurch, Dunedin and Invercargill.

SUBJECTS

A total of 323 randomly selected 6-24-month-old children participated (response rate 61%) of which 263 provided a blood sample.

METHODS

A complete blood cell count, zinc protoporphyrin, serum ferritin and C-reactive protein were measured on nonfasting venipuncture blood samples, 3-day weighed food records and general questionnaire data were collected.

RESULTS

Among children with C-reactive protein<10 mg/l (n=231), 4.3% had iron deficiency anaemia, 5.6% had iron deficiency without anaemia, and 18.6% had depleted iron stores, when a ferritin cutoff of < or =12 g/l was used. Age (negative), sex (girls>boys), ethnicity (Caucasian>non-Caucasian), weight-for-age percentiles (negative) and birth weight (positive) were associated with ferritin after adjusting for infection and socioeconomic status. When current consumption of iron fortified formula and >500 ml of cows' milk per day were included, these were associated with a 22% increase and 25% decrease in ferritin, respectively (R2=0.28).

CONCLUSIONS

The presence of suboptimal iron status (29%) among young New Zealand children is cause for concern, even though severe iron deficiency is rare, because children with marginal iron status are at risk of developing severe iron deficiency if exposed to a physiological challenge.