Iron absorption in breast-fed infants: effects of age,iron status,iron supplements,and complementary foods

BACKGROUND: Iron supplements are often recommended for older breast-fed infants, but little is known about factors affecting iron absorption from human milk or supplements. OBJECTIVE: We investigated the effects of age, iron status, and iron intake on iron absorption in healthy, term, breast-fed infants. DESIGN: Twenty-five infants were randomly assigned to receive either 1) iron supplements (1 mg x kg(-1) x d(-1)) from 4 to 9 mo of age, 2) placebo from 4 to 6 mo and iron supplements from 6 to 9 mo, or 3) placebo from 4 to 9 mo. Infants were exclusively breast-fed to 6 mo and partially breast-fed to 9 mo of age. Iron absorption was assessed by giving (58)Fe with mother's milk at 6 and 9 mo. Blood samples were obtained at 4, 6, and 9 mo, and complementary food intake was recorded at 9 mo. RESULTS: At 6 mo, mean (+/-SD) fractional iron absorption from human milk was relatively low (16.4 +/- 11.4%), with no significant difference between iron-supplemented and unsupplemented infants. At 9 mo, iron absorption from human milk remained low in iron-supplemented infants (16.9 +/- 9.3%) but was higher (P = 0.01) in unsupplemented infants (36.7 +/- 18.9%). Unexpectedly, iron absorption at 9 mo was not correlated with iron status but was significantly correlated with intake of dietary iron, including supplemental iron. CONCLUSIONS: Changes in the regulation of iron absorption between 6 and 9 mo enhance the infant's ability to adapt to a low-iron diet and provide a mechanism by which some, but not all, infants avoid iron deficiency despite low iron intakes in late infancy.     

Dietary iron intake is positively associated with hemoglobin concentration during infancy but not during the second year of life

Iron status during infancy and early childhood reflects highly dynamic processes, which are affected by both internal and external factors. The regulation of iron metabolism seems to be subjected to developmental changes during infancy, although the exact nature of these changes and their implications are not fully understood. We wanted to explore the association between dietary iron intake and indicators of iron status, and to assess temporal changes in these variables. This was done by secondary analysis of data from a recently conducted dietary intervention trial in which healthy, term, well-nourished infants were randomly assigned to consume iron-fortified infant cereals with regular or low phytate content, or iron-fortified infant formula. Dietary iron intake from 6 to 8 mo and from 9 to 11 mo was associated with hemoglobin (Hb) concentration at 9 mo (r = 0.27, P < 0.001) and 12 mo (r = 0.21, P = 0.001), respectively, but iron intake from 12 to 18 mo was not associated with Hb at 18 mo. In contrast, iron intake from 6 to 11 mo was not associated with serum ferritin (S-Ft) at 9 or 12 mo, whereas iron intake from 12 to 17 mo was positively associated with S-Ft at 18 mo (r = 0.14, P = 0.032). These shifts in associations between dietary iron intake, and Hb and S-Ft, respectively, may be due to developmental changes in the channeling of dietary iron to erythropoiesis relative to storage, in the absence of iron deficiency anemia. These observations should be taken into consideration when evaluating iron nutritional status during infancy and early childhood.     

Maternal iron status influences iron transfer to the fetus during the third trimester of pregnancy

BACKGROUND: The effect of maternal iron status on fetal iron deposition is uncertain. OBJECTIVE: We used a unique stable-isotope technique to assess iron transfer to the fetus in relation to maternal iron status. DESIGN: The study group comprised 41 Peruvian women. Of these women, 26 received daily prenatal supplements containing iron and folate (n = 11; Fe group) or iron, folate, and zinc (n = 15; Fe+Zn group) from week 10-24 of pregnancy to 1 mo postpartum. The remaining 15 women (control group) received iron supplementation only during the final month of pregnancy. During the third trimester of pregnancy (+/- SD: 32.9 +/- 1.4 wk gestation) oral 57Fe (10 mg) and intravenous 58Fe (0.6 mg) stable iron isotopes were administered to the women, and isotope enrichment and iron-status indicators were measured in cord blood at delivery. RESULTS: The net amount of 57Fe in the neonates' circulation (from maternal oral dosing) was significantly related to maternal iron absorption (P < 0.005) and inversely related to maternal iron status during the third trimester of pregnancy: serum ferritin (P < 0.0001), serum folate (P < 0.005), and serum transferrin receptors (P < 0.02). Significantly more 57Fe was transferred to the neonates in non-iron-supplemented women: 0.112 +/- 0.031 compared with 0.078 +/- 0.042 mg in the control group (n = 15) and the Fe and Fe+Zn groups (n = 24), respectively (P < 0.01). In contrast, 58Fe tracer in the neonates' circulation was not significantly related to maternal iron status. CONCLUSION: The transfer of dietary iron to the fetus is regulated in response to maternal iron status at the level of the gut.     

Influence of prenatal iron and zinc supplements on supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant Peruvian women

BACKGROUND: It is estimated that 60% of pregnant women worldwide are anemic. OBJECTIVE: We aimed to examine the influence of iron status on iron absorption during pregnancy by measuring supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant women. DESIGN: Subjects were 45 pregnant Peruvian women (33+/-1 wk gestation), of whom 28 received daily prenatal supplements containing 60 mg Fe and 250 microg folate without (Fe group, n = 14) or with (Fe+Zn group, n = 14) 15 mg Zn, which were were consumed from week 10 to 24 of gestation until delivery. The remaining 17 women (control) received no prenatal supplementation. Iron status indicators and isotopes were measured in maternal blood collected 2 wk postdosing with oral (57Fe) and intravenous (58Fe) stable iron isotopes. RESULTS: Maternal serum ferritin and folate concentrations were significantly influenced by supplementation (P < 0.05). Serum iron was also significantly higher in the Fe than in the Fe+Zn (P < 0.03) or control (P < 0.001) groups. However, the supplemented groups had significantly lower serum zinc concentrations than the control group (8.4+/-2.3 and 10.9+/-1.8 micromol/L, respectively, P < 0.01). Although percentage iron absorption was inversely related to maternal serum ferritin concentrations (P = 0.036), this effect was limited and percentage iron absorption did not differ significantly between groups. CONCLUSIONS: Because absorption of nonheme iron was not substantially greater in pregnant women with depleted iron reserves, prenatal iron supplementation is important for meeting iron requirements during pregnancy.     

Determination of iron absorption from intrinsically labeled microencapsulated ferrous fumarate (sprinkles) in infants with different iron and hematologic status by using a dual-stable-isotope method

BACKGROUND: The use of microencapsulated ferrous fumarate sprinkles is a new approach for home fortification. Iron and hematologic status may affect the absorption of iron from sprinkles. OBJECTIVE: The objective was to measure the absorption (corrected erythrocyte incorporation of (57)Fe) of 2 different doses of iron from sprinkles added to a maize-based complementary food provided to infants with different iron and hematologic status. DESIGN: Infants aged 6-18 mo were randomly assigned to receive either 30 (n = 45) or 45 (n = 45) mg elemental Fe as (57)Fe-labeled sprinkles added to a maize-based porridge on 3 consecutive days. A (58)Fe tracer (0.2 mg as ferrous citrate) was also infused intravenously (n = 46). Blood was drawn at baseline and 14 d later to determine erythrocyte incorporation of (57)Fe and (58)Fe by using inductively coupled plasma mass spectrometry. On the basis of hemoglobin and soluble transferrin receptor concentrations, subjects were classified as having iron deficiency anemia (IDA), iron deficiency (ID), or sufficient iron status. RESULTS: There was no significant effect of dose on iron absorption (P > 0.05). Geometric mean iron absorption was 8.25% (range: 2.9-17.8%) in infants with IDA (n = 32), 4.48% (range: 1.1-10.6%) in infants with ID (n = 20), and 4.65% (range: 1.5-12.3%) in iron-sufficient infants (n = 20). Geometric mean iron absorption was significantly higher in infants with IDA than in infants with ID or iron-sufficient infants (P = 0.0004); however, there were no significant differences between infants with ID and iron-sufficient infants. CONCLUSION: During infancy, iron absorption from sprinkles in a maize-based porridge meets and surpasses requirements for absorbed iron and is up-regulated in infants with IDA.     

Iron absorption is more closely related to iron status than to daily iron intake in 12- to 48-mo-old children

Few studies have evaluated iron absorption in small children after the first year of life. Our objectives were to examine the relations among iron intake, iron absorption, and iron status in a group of healthy children. We studied 28 children, ages 12 to 48 mo, after a 7-d home adaptation to a diet representative of their usual daily mineral intake. A multi-tracer stable isotope study was performed to assess iron absorption both from a meal ((58)Fe) and from a reference iron dose ((57)Fe) given with ascorbic acid without a meal. Iron intake was 6.9 +/- 2.4 mg, approximately the 35th percentile of typical U.S. intakes. Absorption of (58)Fe was related to serum ferritin (r(2) = 0.319, P = 0.0018) and more so to reference dose iron absorption (r(2) = 0.653, P < 0.0001). Iron absorption was negatively correlated with zinc intake (r(2) = 0.090, P = 0.0049) but was not correlated with iron intake (P = 0.20). However, zinc intake was not correlated with measures of iron status, including reference dose iron absorption and serum ferritin (r(2) < 0.1, P > 0.25). Total absorbed iron was similar to needs estimated by the Institute of Medicine. We conclude that iron absorption in young children is more closely related to iron status than to iron intake. Reference dose iron absorption may be superior to serum ferritin as a surrogate measure for iron status in this age group. Although zinc intake may affect iron absorption from a meal, it does not appear to have a detectable effect on overall iron status in otherwise well-nourished children.     

α-Lactalbumin and casein-glycomacropeptide do not affect iron absorption from formula in healthy term infants

Iron absorption from infant formula is relatively low. α-Lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of α-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. Thirty-one infants were randomly assigned to receive 1 of 3 formulas (4 mg iron/L, 13.1 g protein/L) from 4-8 wk to 6 mo of age: commercially available whey-predominant standard infant formula (standard formula), α-lactalbumin-enriched infant formula (α-LAC), or α-lactalbumin-enriched/casein-glycomacropeptide-reduced infant formula (α-LAC/RGMP). Nine breast-fed infants served as a reference. At 5.5 mo of age, (58)Fe was administered to all infants in a meal. Blood samples were collected 14 d later for iron absorption and iron status indices. Iron deficiency was defined as depleted iron stores, iron-deficient erythropoiesis, or iron deficiency anemia. Iron absorption (mean ± SD) was 10.3 ± 7.0% from standard formula, 8.6 ± 3.8% from α-LAC, 9.2 ± 6.5% from α-LAC/RGMP, and 12.9 ± 6.5% from breast milk, with no difference between the formula groups (P = 0.79) or all groups (P = 0.44). In the formula-fed infants only, iron absorption was negatively correlated with serum ferritin (r = -0.49; P = 0.005) and was higher (P = 0.023) in iron-deficient infants (16.4 ± 12.4%) compared with those with adequate iron status (8.6 ± 4.4%). Our findings indicate that α-lactalbumin and casein-glycomacropeptide do not affect iron absorption from infant formula in infants. Low serum ferritin concentrations are correlated with increased iron absorption from infant formula.     

Daily iron alone but not in combination with multimicronutrients increases plasma ferritin concentrations in indonesian infants with inflammation

Iron deficiency is a public health problem in infancy. We assessed the efficacy of iron supplements in infants with inflammation on iron status and subsequent inflammation. This was a prospective, nested, case-control study of 6- to 12-mo-old infants participating in the International Research on Infant Supplementation study, Indonesia. Cases (n = 46) were selected on the basis of their inflammation status at baseline, C-reactive protein (>5 mg/L) or alpha-1 acid glycoprotein (>1 g/L); there were 44 controls without inflammation. Infants received 10 mg/d of elemental iron alone or in combination with multimicronutrients, or placebo. Blood samples were collected at baseline and at 6 mo for determinations of plasma ferritin, zinc, copper, retinol, beta-carotene, alpha-tocopherol, and inflammation status. Data on breast-feeding and acute respiratory infections (ARI) were collected daily. At baseline, 33% of infants had iron deficiency, and those with inflammation had lower retinol, beta-carotene, higher concentrations of copper and higher rates of ARI compared with controls. After 6 mo, compared with infants given placebo, ferritin concentration increased significantly in infants administered iron alone independently of inflammation status at baseline or at the end of the study. In those given multimicronutrients with iron, ferritin increased significantly in infants who did not have inflammation at baseline or at the end of the study compared with those given placebo. Consequently, iron alone resolved iron deficiency, whereas multimicronutrients reduced the deterioration of iron stores compared with placebo (chi(2), P < 0.05), without enhancing inflammation. Iron alone is recommended in populations in which iron deficiency is a public health problem despite the presence of inflammation in infants who are still breast-feeding.     

Erythrocyte iron incorporation but not absorption is increased by intravenous iron administration in erythropoietin-treated premature infants

Because critically ill premature infants experience significant iron loss due to phlebotomy and have high iron needs for growth, Fe absorption and incorporation studies are clinically important. A prospective, controlled, randomized, open 21-d study was conducted in infants with birth weight <1300 g and gestational age < 31 wk to assess the efficacy of combining intravenous (IV) sucrose iron (Fe) with erythropoietin (EPO) for increasing Fe absorption, RBC Fe incorporation, and erythropoiesis. Three clinically stable groups were enrolled at 3-4 wk of age: Control, EPO [2100 U EPO/(kg.wk)]; and IV Fe+EPO [2 mg IV sucrose Fe/(kg.d) plus 2100 U EPO/(kg.wk)]. All subjects received 9 mg/(kg.d) of oral Fe polymaltose. Subjects were not allowed RBC transfusions. Indicators of iron status and erythropoiesis were assessed before and 18 d after treatment. On d 4, tracer doses of oral polymaltose (57)Fe and IV sucrose (58)Fe were administered, and stool and blood samples were collected for Fe absorption and incorporation determinations. Compared with the Control group, the EPO group demonstrated greater hemoglobin (Hb) concentration and reticulocyte count, but no difference in Fe incorporation. In contrast, the IV Fe+EPO group demonstrated greater total Fe incorporation, Hb concentration, plasma ferritin, and reticulocyte count compared with the Control and EPO groups. Absorption of (57)Fe and nonisotopic polymaltose Fe did not differ among the groups (range: 48-58%, and 41-47%, respectively). We conclude that IV sucrose Fe administered in combination with EPO to very-low-birth weight premature infants significantly increases RBC Fe incorporation and erythropoiesis more than EPO alone, but without increasing iron absorption.     

Zinc and iron nutrition in Chilean children fed fortified milk provided by the Complementary National Food Program

OBJECTIVE: Chilean infants are at risk for isolated zinc and iron deficiencies because of a low consumption of animal products in low socioeconomic sectors. In 1999, the National Complementary Food Program of Chile manufactured a new milk (2 kg of powdered milk/mo) fortified with iron (Fe; 10 mg/L), zinc (Zn; 5 mg/L), and copper (0.5 mg/L) to be provided to infants until age 18 mo and to pregnant women. We analyzed the nutrition status of zinc and iron at age 18 mo in infants who consumed the fortified cow's milk. METHODS: Forty-two healthy male children with normal growth and from lower socioeconomic groups were studied. A nutrition survey was conducted; blood and hair samples for Zn in plasma and hair, hemoglobin, hematocrit, and serum ferritin were obtained. RESULTS: Mean intakes were: energy, 106 +/- 27 kcal. kg(-1). d(-1); protein, 3.8 +/- 1.1 g. kg(-1). d(-1); Zn, 5.2 +/- 1.9 g/d (0.98 mg Zn/MJ; 68% of World Health Organization recommendations); Fe, 11.2 +/- 5.5 mg/d; and dietary fiber, 9.8 +/- 3.9 g/d. Plasma Zn in 54.8% of children was no greater than 12.3 microM/L; 36% had hair Zn level no greater than 1.23 microM/g and 39% had serum ferritin levels no greater than 10 microg/dL (12% were anemic). Hair Zn was correlated to socioeconomic level (Spearman's rank correlation, r = -0.53; P < 0.001) and plasma Zn was correlated to the z weight/length (r = 0.47; P < 0.05), subscapular skinfold (r = 0.46; P < 0.05), and Zn intake (r = 0.46; P < 0.05). CONCLUSIONS: The fortified powdered cow's milk provided to infants until age 18 mo by the Complementary Food Program in Chile favorably affects the Fe status of these children, but possibly not the Zn nutrition; we suggest re-evaluation of the levels of Zn fortification.     

The diagnostic criteria for iron deficiency in infants should be reevaluated

Diagnostic criteria for iron deficiency (ID) and iron deficiency anemia (IDA) in infants are poorly defined. Our aim was to establish appropriate cut-off values for hemoglobin (Hb), plasma ferritin, erythrocyte mean cell volume (MCV), zinc protoporphyrin (ZPP) and soluble transferrin receptors (TfR) in infancy. Exclusively breast-fed infants (n = 263) in Honduras and Sweden were randomly assigned to receive iron supplementation or placebo, and blood samples were obtained at 4, 6 and 9 mo of age. Reference ranges were determined using three different approaches for defining iron-replete infants. The usefulness of several variables for predicting the Hb response to iron was evaluated. We found the following 2 SD cut-off values in iron-replete infants: Hb <105 g/L at 4-6 mo and <100 g/L at 9 mo; ZPP >75 micro mol/mol heme at 4-6 mo and >90 micro mol/mol heme at 9 mo; ferritin <20 micro g/L at 4 mo, <9 micro g/L at 6 mo and <5 micro g/L at 9 mo; and TfR >11 mg/L at 4-9 mo. The Hb response to iron was not a useful definition of IDA at 4 mo of age. Hb, MCV and ZPP at 6 mo as well as growth variables predicted the Hb response at 6-9 mo, but ferritin and TfR at 6 mo did not. We conclude that there is need for a reevaluation of the definitions of ID and IDA in infants.     

Randomized trial of calcium glycerophosphate-supplemented infant formula to prevent lead absorption.

BACKGROUND: Although additional dietary calcium is recommended frequently to reduce the risk of lead poisoning, its role in preventing lead absorption has not been evaluated clinically. OBJECTIVE: The objective was to determine the safety and to estimate the size of the effect of calcium- and phosphorus-supplemented infant formula in preventing lead absorption. DESIGN: One hundred three infants aged 3.5-6 mo were randomly assigned to receive iron-fortified infant formula (465 mg Ca and 317 mg P/L) or the same formula with added calcium glycerophosphate (1800 mg Ca and 1390 mg P/L) for 9 mo. RESULTS: There was no significant difference between groups in the mean ratio of urinary calcium to creatinine, serum calcium and phosphorus, or change in iron status (serum ferritin, total iron binding capacity). At month 4, the median (+/-SD) increase from baseline in blood lead concentration for the supplemented group was 57% of the increase for the control group (0.04 +/- 0.09 compared with 0.07 +/- 0.10 micromol/L; P = 0.039). This effect was attenuated during the latter half of the trial, with an overall median increase in blood lead concentration from baseline to month 9 of 0.12 +/- 0.13 micromol/L for the control group and 0.10 +/- 0.18 micromol/L for the supplemented group (P = 0.284). CONCLUSIONS: Supplementation did not have a measurable effect on urinary calcium excretion, calcium homeostasis, or iron status. The significant effect on blood lead concentrations during the first 4 mo was in the direction expected; however, because this was not sustained throughout the 9-mo period we cannot conclude that the calcium glycerophosphate supplement prevented lead absorption in this population.     

Absorption and loss of iron in toddlers are highly correlated

For estimating the requirements for dietary iron, it is important to know the amount of iron that is lost from the body. Inevitable losses of iron have been determined in adult humans but not in infants or children. We administered (58)Fe, the least abundant stable isotope of iron, to free-living infants at 168 d of age (5.6 mo) and followed them to age 26 mo. There was no dietary restriction after isotope administration. Blood was obtained at regular intervals for determination of isotopic enrichment and indices of iron status. We estimated the quantity of circulating iron, noncirculating active iron, and storage iron at each age. The administered isotope equilibrated with total body iron by 13 mo of age. From 13 to 26 mo of age, we estimated inevitable loss and absorption of iron from the change in tracer abundance in circulating iron. The rate of decrease of tracer abundance was proportional to addition of tracee, i.e., absorption of iron. Conversely, the rate of decrease in quantity of tracer was proportional to removal of tracee, i.e., loss of iron. From 13 to 26 mo of age, iron absorption was (mean +/- SD) 0.49 +/- 0.13 mg/d and inevitable iron loss was 0.25 +/- 0.12 mg/d. Intersubject variability of iron loss and iron absorption was high, and iron loss and absorption were highly correlated (r = 0.789, P < 0.001). Iron stores were low throughout the study and decreased significantly from 13 to 26 mo of age, suggesting that iron absorption from the diet was inadequate to maintain or increase iron nutritional status. The data suggest that, in this cohort, which may be representative, the intake of bioavailable iron from 13 to 26 mo of age was insufficient to maintain iron nutritional status.     

Ferrous sulfate is more bioavailable among preschoolers than other forms of iron in a milk-based weaning food distributed by PROGRESA, a national program in Mexico

After 1 y of distributing a milk-based fortified weaning food provided by the Mexican social program PROGRESA, positive effects on physical growth, prevalence of anemia, and several vitamin deficiencies were observed. There was no effect on iron status, which we hypothesized was related to the poor bioavailability of the reduced iron used as a fortificant in PROGRESA. The objective of this study was to compare the iron bioavailability from different iron sources added as fortificants to the weaning food. Children (n = 54) aged 2-4 y were randomly assigned to receive 44 g of the weaning food fortified with ferrous sulfate, ferrous fumarate, or reduced iron + Na(2)EDTA. Iron absorption was measured using an established double-tracer isotopic methodology. Iron absorption from ferrous sulfate (7.9 +/- 9.8%) was greater than from either ferrous fumarate (2.43 +/- 2.3%) or reduced iron + Na(2)EDTA (1.4 +/- 1.3%) (P < 0.01). The absorption of log-(58)Fe sulfate given with the iron source correlated with serum ferritin (s-ferritin) concentration (n = 13, r = 0.63, P = 0.01) and log-(57)Fe absorption (reference dose) (n = 14, r = -0.52, P = 0.02). Absorption from ferrous fumarate and reduced iron + Na2EDTA did not correlate with s-ferritin or absorption of (57)Fe. The recommended daily portion of the fortified complementary food provides an average of 0.256, 0.096, 0.046 mmol (1.44, 0.54, and 0.26 mg) of absorbed iron, if fortified with sulfate, fumarate and reduced iron + Na(2)EDTA, respectively. Ferrous sulfate was more bioavailable than either ferrous fumarate or reduced iron + Na(2)EDTA when added to the milk-based fortified food and more readily met the average daily iron requirements for children 2-3 y of age.     

Exclusive breast-feeding for 6 months, with iron supplementation, maintains adequate micronutrient status among term, low-birthweight, breast-fed infants in Honduras

There is little information on the risk of micronutrient deficiencies during the period of exclusive breast-feeding. We evaluated this among term, low-birthweight (LBW; 1500-2500 g) infants in Honduras. Mother-infant pairs were recruited in the hospital and assisted with exclusive breast-feeding during the first 4 mo. At 4 mo, infants were randomly assigned to either continue exclusive breast-feeding to 6 mo (EBF; n = 59) or be given iron-fortified complementary foods (rice, chicken, fruits, and vegetables) from 4 to 6 mo while continuing to breast-feed (SF, n = 60). Blood samples were collected at 2, 4, and 6 mo and analyzed for hemoglobin (Hb), hematocrit, plasma ferritin, % transferrin saturation, vitamin A, vitamin B-12, folate, zinc, and erythrocyte folate. Infants with Hb < 100 g/L at 2 or 4 mo were given medicinal iron supplements for 2 mo; the proportion administered iron drops did not differ significantly between groups. There was no significant effect of complementary foods on indices of vitamin A, B-12, folate, or zinc status. Among infants not given medicinal iron at 4-6 mo, iron status was higher in the SF group than the EBF group. In those given medicinal iron at 4-6 mo, iron status was higher in the EBF group, suggesting that complementary foods interfered with iron utilization. About half of the infants were anemic by 2 mo, before the age when complementary foods would be recommended. This supports the recommendation that LBW infants should receive iron supplementation in early infancy. Given that infants given iron supplements did not benefit from complementary foods at 4-6 mo, we conclude that exclusive breast-feeding for 6 mo (with iron supplementation) can be recommended for term, LBW infants.     

A randomized, community-based trial of the effects of improved, centrally processed complementary foods on growth and micronutrient status of Ghanaian infants from 6 to 12 mo of age.

BACKGROUND: Koko, a fermented maize porridge used as the primary complementary food in Ghana, has been implicated in the high prevalence of child malnutrition. Weanimix, a cereal-legume blend developed by the United Nations Children's Fund and the Ghanaian government, has been promoted as an alternative. OBJECTIVE: We evaluated the effect of feeding Weanimix and 3 other locally formulated, centrally processed complementary foods on the nutritional status of 208 breast-fed infants. DESIGN: Infants were randomly assigned to receive 1 of 4 foods from 6 to 12 mo of age: Weanimix (W), Weanimix plus vitamins and minerals (WM), Weanimix plus fish powder (WF), and koko plus fish powder (KF). Dietary and anthropometric data were collected regularly. Blood was collected at 6 and 12 mo of age to assess iron, zinc, vitamin A, and riboflavin status. Before and after the intervention, cross-sectional data on the anthropometric status of infants not included in the intervention (NI; n = 464) were collected. RESULTS: There were no significant differences between intervention groups in weight or length gain or in hemoglobin, hematocrit, transferrin saturation, plasma zinc, or erythrocyte riboflavin values between 6 and 12 mo of age. From 9 to 12 mo of age, z scores were lower in NI infants than in the combined intervention groups [at 12 mo: -1.71 +/- 0.90 compared with -1.19 +/- 0.93 for weight and -1.27 +/- 1.02 compared with -0.63 +/- 0.84 for length (P < 0.001 for both), respectively]. The percentage of infants with low ferritin values increased significantly between 6 and 12 mo of age in groups W, WF, and KF but not in group WM. Change in plasma retinol between 6 and 12 mo of age was significantly greater in group WM than in the other 3 groups combined (0.14 +/- 0.3 compared with -0.04 +/- 0.3 micromol/L, P = 0. 003). CONCLUSIONS: All 4 foods improved growth relative to the NI group. Infants fed WM had better iron stores and vitamin A status than those fed nonfortified foods.     

Weekly iron supplementation does not block increases in serum zinc due to weekly zinc supplementation in Bangladeshi infants

Because infants and young children in many developing countries are deficient in both iron and zinc, and zinc can affect iron metabolism, evaluation of optimum strategies to simultaneously supplement iron and zinc is an important public health priority. This study evaluated the efficacy of weekly supplementation of iron or zinc or both on iron, zinc, and copper status in Bangladeshi infants. In a double-blind, randomized, controlled community trial, 6-mo-old infants were assigned to receive weekly supplements of 1 mg riboflavin (control, n = 82) or 1 mg riboflavin + 20 mg iron (n = 83), 20 mg zinc (n = 83), or both (n = 85) for 6 mo. Hemoglobin, serum ferritin, transferrin receptor, zinc, and copper concentrations were measured at baseline and at the end of intervention. Serum Zn increased in both groups receiving zinc; the increase was greatest among children with low baseline serum zinc concentration. Iron status indicators did not differ among the groups before or after 6 mo of supplementation. Supplementation with either zinc or iron decreased serum copper after 6 mo. Joint supplementation did not alter the individual effects of iron or zinc supplementation in these Bangladeshi children. However, the dosing regimen may not have been adequate to achieve the desired biochemical effects.     

A community-based randomized controlled trial of iron and zinc supplementation in Indonesian infants: interactions between iron and zinc

BACKGROUND: Combined supplementation with iron and zinc during infancy may be effective in preventing deficiencies of these micronutrients, but knowledge of their potential interactions when given together is insufficient. OBJECTIVE: The goal was to compare the effect in infants of combined supplementation with iron and zinc and of supplementation with single micronutrients on iron and zinc status. DESIGN: Indonesian infants (n = 680) were randomly assigned to daily supplementation with 10 mg Fe (Fe group), 10 mg Zn (Zn group), 10 mg Fe + 10 mg Zn (Fe+Zn group), or placebo from 6 to 12 mo of age. Venous blood samples were collected at the start and end of the study. Five hundred forty-nine infants completed the supplementation and had both baseline and follow-up blood samples available for analysis. RESULTS: Baseline prevalences of anemia, iron deficiency anemia (anemia and low serum ferritin), and low serum zinc (< 10.7 micromol/L) were 41%, 8%, and 78%, respectively. After supplementation, the Fe group had higher hemoglobin (119.4 compared with 115.3 g/L; P < 0.05) and serum ferritin (46.5 compared with 32.3 microg/L; P < 0.05) values than did the Fe+Zn group, indicating an effect of zinc on iron absorption. The Zn group had higher serum zinc (11.58 compared with 9.06 micromol/L; P < 0.05) than did the placebo group. There was a dose effect on serum ferritin in the Fe and Fe+Zn groups, but at different levels. There was a significant dose effect on serum zinc in the Zn group, whereas no dose effect was found in the Fe+Zn group beyond 7 mg Zn/d. CONCLUSION: Supplementation with iron and zinc was less efficacious than were single supplements in improving iron and zinc status, with evidence of an interaction between iron and zinc when the combined supplement was given.     

Iron and zinc supplementation improved iron and zinc status, but not physical growth, of apparently healthy, breast-fed infants in rural communities of northeast Thailand

Iron deficiency is prevalent in children and infants worldwide. Zinc deficiency may be prevalent, but data are lacking. Both iron and zinc deficiency negatively affect growth and psychomotor development. Combined iron and zinc supplementation might be beneficial, but the potential interactions need to be verified. In a randomized, placebo-controlled trial using 2 x 2 factorial design, 609 Thai infants aged 4-6 mo were supplemented daily with 10 mg of iron and/or 10 mg of zinc for 6 mo to investigate effects and interactions on micronutrient status and growth. Iron supplementation alone increased hemoglobin and ferritin concentrations more than iron and zinc combined. Anemia prevalence was significantly lower in infants receiving only iron than in infants receiving iron and zinc combined. Baseline iron deficiency was very low, and iron deficiency anemia was almost nil. After supplementation, prevalence of iron deficiency and iron deficiency anemia were significantly higher in infants receiving placebo and zinc than in those receiving iron or iron and zinc. Serum zinc was higher in infants receiving zinc (16.7 +/- 5.2 micromol/L), iron and zinc (12.1 +/- 3.8 micromol/L) or iron alone (11.5 +/- 2.5 micromol/L) than in the placebo group (9.8 +/- 1.9 micromol/L). Iron and zinc interacted to affect iron and zinc status, but not hemoglobin. Iron supplementation had a small but significant effect on ponderal growth, whereas zinc supplementation did not. To conclude, in Thai infants, iron supplementation improved hemoglobin, iron status, and ponderal growth, whereas zinc supplementation improved zinc status. Overall, for infants, combined iron and zinc supplementation is preferable to iron or zinc supplementation alone.     

Effect of daily or weekly multiple-micronutrient and iron foodlike tablets on body iron stores of Indonesian infants aged 6-12 mo: a double-blind, randomized, placebo-controlled trial

BACKGROUND: There is still uncertainty about the best procedure to alleviate iron deficiency. Additionally more reliable methods are needed to assess the effect of iron intervention. OBJECTIVE: We examined the efficacy of daily iron (10 mg), daily and weekly multiple-micronutrient supplementation (10 and 20 mg Fe, respectively) in improving body iron stores of Indonesian infants. DESIGN: Infants aged 6-12 mo were randomly allocated to 1 of 4 groups: daily multiple-micronutrients (DMM) foodlike tablets (foodLETs), weekly multiple-micronutrient (WMM) foodLETs, daily iron (DI) foodLETs, or daily placebo. Hemoglobin, ferritin, transferrin receptors, and C-reactive protein data were obtained at baseline and 23 wk. RESULTS: Body iron estimated from the ratio of transferrin receptors to ferritin was analyzed for 244 infants. At baseline, mean iron stores (0.5 +/- 4.1 mg/kg) did not differ among the groups, and 45.5% infants had deficits in tissue iron (body iron < 0). At week 23, the group DI had the highest increment in mean body iron (4.0 mg/kg), followed by the DMM group (2.3 mg/kg; P < 0.001 for both). The iron stores in the WMM group did not change, whereas the mean body iron declined in the daily placebo group (-2.2 mg/kg; P < 0.001). Compared with the daily placebo group, the DMM group gained 4.55 mg Fe/kg, the DI group gained 6.23 mg Fe/kg (both P < 0.001), and the WMM group gained 2.54 mg Fe/kg (P = 0.001). CONCLUSIONS: When compliance can be ensured, DI and DMM foodLETs are efficacious in improving and WMM is efficacious in maintaining iron stores among Indonesian infants.