Antenatal supplementation with micronutrients and biochemical indicators of status and subclinical infection in rural Nepal

BACKGROUND: Previously we showed that women in rural Nepal experience multiple micronutrient deficiencies in early pregnancy. OBJECTIVE: This study examined the effects of daily antenatal micronutrient supplementation on changes in the biochemical status of several micronutrients during pregnancy. DESIGN: In Nepal, we conducted a randomized controlled trial in which 4 combinations of micronutrients (folic acid, folic acid + iron, folic acid + iron + zinc, and a multiple micronutrient supplement containing folic acid, iron, zinc, and 11 other nutrients) plus vitamin A, or vitamin A alone as a control, were given daily during pregnancy. In a subsample of subjects (n = 740), blood was collected both before supplementation and at approximately 32 wk of gestation. RESULTS: In the control group, serum concentrations of zinc, riboflavin, and vitamins B-12 and B-6 decreased, whereas those of copper and alpha-tocopherol increased, from the first to the third trimester. Concentrations of serum folate, 25-hydroxyvitamin D, and undercarboxylated prothrombin remained unchanged. Supplementation with folic acid alone or folic acid + iron decreased folate deficiency. However, the addition of zinc failed to increase serum folate, which suggests a negative inhibition; multiple micronutrient supplementation increased serum folate. Folic acid + iron + zinc failed to improve zinc status but reduced subclinical infection. Multiple micronutrient supplementation decreased the prevalence of serum riboflavin, vitamin B-6, vitamin B-12, folate, and vitamin D deficiencies but had no effect on infection. CONCLUSIONS: In rural Nepal, antenatal supplementation with multiple micronutrients can ameliorate, to some extent, the burden of deficiency. The implications of such biochemical improvements in the absence of functional and health benefits remain unclear.     

Zinc plus beta-carotene supplementation of pregnant women is superior to beta-carotene supplementation alone in improving vitamin A status in both mothers and infants

BACKGROUND: Deficiencies of vitamin A, iron, and zinc are prevalent in women and infants in developing countries. Supplementation during pregnancy can benefit mother and infant. OBJECTIVE: We examined whether supplementation during pregnancy with iron and folic acid plus beta-carotene or zinc or both improves the micronutrient status of mothers and infants postpartum. DESIGN: Pregnant women (n = 170) were supplemented daily only during pregnancy with beta-carotene (4.5 mg), zinc (30 mg), or both or placebo plus iron (30 mg) and folic acid (0.4 mg) in a randomized, double-blind, placebo-controlled trial. Micronutrient status was assessed 1 and 6 mo postpartum. RESULTS: Six months postpartum, plasma retinol concentrations were higher in the women who received zinc during pregnancy than in women who did not. Infants born to mothers supplemented with beta-carotene + zinc had higher plasma retinol concentrations, with the frequency of vitamin A deficiency reduced by >30% compared with the other 3 groups. Breast-milk beta-carotene concentrations were higher in all women supplemented with beta-carotene, but breast-milk retinol concentrations were higher only in women who received beta-carotene + zinc. Zinc concentrations did not differ among groups in mothers and infants. CONCLUSIONS: Zinc supplementation during pregnancy improved the vitamin A status of mothers and infants postpartum, which indicates a specific role of zinc in vitamin A metabolism. Addition of both beta-carotene and zinc to iron supplements during pregnancy could be effective in improving the vitamin A status of mothers and infants.     

Redistribution of vitamin A after iron supplementation in Indonesian infants

BACKGROUND: Deficiencies of iron and vitamin A are prevalent worldwide. Single-micronutrient supplementation is widely used to combat these deficiencies. However, micronutrient deficiencies often occur concurrently, and there are many interactions between micronutrients. OBJECTIVE: This study investigated interactions among 3 important micronutrients--iron, vitamin A, and zinc--when they are given as supplements. DESIGN: In a randomized, double-blind, placebo-controlled supplementation trial, 387 Indonesian infants aged 4 mo were supplemented 5 d/wk for 6 mo with 10 mg Fe, 10 mg Zn, 2.4 mg beta-carotene, 10 mg each of Fe and Zn, 10 mg Zn + 2.4 mg beta-carotene, or placebo. Complete data on micronutrient status, including hemoglobin, ferritin, retinol, zinc, and the modified relative dose response (a measure of liver retinol stores), were available from 256 infants at the end of the study. RESULTS: Iron-supplemented infants had significantly lower plasma retinol concentrations and a significantly higher prevalence of vitamin A deficiency, as defined by a plasma retinol concentration <0.70 micromol/L, than did the non-supplemented infants. In contrast, the modified relative dose response of the iron-supplemented infants indicated greater liver stores of vitamin A. Iron supplementation improved iron status, and zinc supplementation improved zinc status, but beta-carotene supplementation did not significantly improve vitamin A status. CONCLUSIONS: In this study, iron supplementation in infants with marginal vitamin A status led to lower plasma vitamin A concentrations and simultaneously to greater vitamin A liver stores. This implies a redistribution of retinol after iron supplementation, which might induce vitamin A deficiency. Therefore, iron supplementation in infants should be accompanied by measures to improve vitamin A status.     

Multiple micronutrient supplements improve micronutrient status and anemia but not growth and morbidity of Indonesian infants: a randomized, double-blind, placebo-controlled trial

Multiple micronutrient deficiencies are highly prevalent in Indonesia, but the interventions are still focused on single micronutrients. This study aimed to investigate the efficacy of multiple micronutrient supplements for improving micronutrient status, anemia, growth, and morbidity of Indonesian infants. In this double-blind, placebo-controlled trial, 284 infants aged 6-12 mo were randomly allocated to 4 treatment groups for 23 wk; 260 (92%) infants completed the study. Group 1 (DMM) received one adequate intake of multiple micronutrient supplements daily (n = 66); group 2 (WMM) received 2 adequate intakes of multiple micronutrient on 1d plus 6 d of placebo (n = 60); group 3 (DI) received 10 mg of iron supplement daily (n = 69); group 4 received a placebo supplement daily (n = 65). Blood samples were collected at baseline and at posttreatment to assess anemia and micronutrient status. Anthropometric measurements were taken monthly, and morbidity was recorded daily. At baseline, 58.1% of infants were anemic, 34.2% were iron deficient, 21.3% were vitamin A deficient, and 11% were zinc deficient. The DMM and DI supplements both corrected iron deficiency, but DMM supplements were more efficacious in improving hemoglobin levels of anemic infants than the other supplements. However, anemia still persisted in one-third of DMM infants posttreatment. The DMM supplement was more efficacious than WMM or DI supplementation in improving infant status of other micronutrients, including zinc, tocopherol, and riboflavin, whereas DI exacerbated zinc deficiency. There were no significant differences in growth and morbidity among treatment groups, and growth faltering was not prevented.     

Efficacy of combined iron and zinc supplementation on micronutrient status and growth in Vietnamese infants

OBJECTIVE: To evaluate the effect of combined iron-zinc supplementation on micronutrient status, growth and morbidity. DESIGN: Randomized, double-masked, placebo-controlled supplementation trial. SETTING: Rural district of Que Vo, in the Red River Delta in Vietnam. SUBJECTS: A total of 915 breast-fed infants aged 4-7 months were included and 784 completed the study. INTERVENTIONS: The Fe-group received daily and for a 6-month period 10 mg of iron, the Zn-group 10 mg zinc, the Fe-Zn group 10 mg iron+10 mg zinc and the placebo group a placebo. Hemoglobin (Hb), serum ferritin (SF) and zinc (SZn), and anthropometry were measured before and at the end of the intervention. Morbidity was recorded daily. RESULTS: Changes of Hb and SF were higher in both Fe and Fe+Zn groups (respectively 22.6 and 20.6 g/l for Hb; 36.0 and 24.8 microg/l for SF) compared to Zn and placebo groups (Hb: 6.4 and 9.8 g/l; SF: -18.2 and -16.9 microg/l, P<0.0001). SZn increased more in Zn group (10.3 micromol/l) than in Fe+Zn group (8.0 micromol/l, P=0.03) and more in these groups compared to Fe and placebo groups (1.6 and 1.2 micromol/l, P<0.0001). Weight gain was higher in the Zn group. No significant effects of supplementations on growth in length or morbidity. CONCLUSIONS: Combined iron-zinc supplementation had a positive effect on iron and zinc status in infants. However, the positive effect of zinc alone on SZn and weight would indicate a negative interaction of iron when added to zinc supplements. SPONSORSHIP: UNICEF New York.     

Low maternal vitamin B-12 status is associated with offspring insulin resistance regardless of antenatal micronutrient supplementation in rural Nepal

Questions have been raised about potentially negative effects of antenatal folic acid use in populations with a high prevalence of vitamin B-12 deficiency. Our objective was to examine the association between maternal folate and vitamin B-12 status in pregnancy on offspring insulin resistance and examine whether the effects of maternal micronutrient supplementation varied by baseline maternal folate and/or vitamin B-12 status. Pregnant women were cluster randomized to receive daily supplements containing vitamin A alone or with folic acid, folic acid+iron, folic acid+iron+zinc, or a multiple micronutrient. In a subsample (n = 1132), micronutrient status biomarkers were analyzed at baseline and late pregnancy. Children born to the women who participated in the trial were visited at 6-8 y of age. Fasting plasma glucose and insulin were used to estimate insulin resistance using the homeostasis model assessment (HOMA-IR). Children whose mothers were deficient in vitamin B-12 (<148 pmol/L, 27%) during early pregnancy had a 26.7% increase in HOMA-IR (P = 0.02), but there was no association with maternal folate status. Among children born to women who were vitamin B-12 deficient at baseline, the percent difference in HOMA-IR compared to the control group was 15.1% (95% CI: -35.9, 106.4), 4.9% (-41.6, 88.5), 3.3% (-38.4, 73.5), and 18.1% (-29.0, 96.7) in the folic acid, folic acid-iron, folic acid-iron-zinc, and multiple micronutrient supplementation groups, respectively, none of which were significant. Maternal vitamin B-12 deficiency is associated with an elevated risk of insulin resistance, but supplementation with folic acid or other micronutrients led to no significant change in insulin resistance in school-aged offspring.     

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.     

Micronutrients and reproductive health issues: an international perspective

Micronutrients may have a role in enhancing reproductive health of women living in the developing world. Two illustrative micronutrients, zinc and vitamin A, have received some attention in this regard. Numerous animal experiments and observational studies suggest the potential role of zinc deficiency in labor and delivery-related complications such as premature rupture of membrane, placental abruption, preterm labor and inefficient uterine contraction. These associations have not been confirmed in supplementation studies. Zinc does not appear to be a limiting factor in intrauterine growth in the developing world, contrary to some evidence of its suggested benefit among women residing in industrialized countries. One study in Nepal found that maternal vitamin A or beta-carotene supplementation reduces pregnancy-related mortality but not infant mortality. These findings are corroborated by observations of the significantly higher risk of mortality among night-blind women compared to non-night-blind women long after the termination of pregnancy and the resolution of night blindness. Maternal multiple micronutrient supplementation needs more careful evaluation before its use in large-scale programs. Two recent trials indicated that a prenatal multiple micronutrient supplement provides no added advantage over iron and folate in reducing outcomes such as low birth weight and probably no survival benefit. Data are also suggestive that adding zinc may negate the beneficial effect of iron and folic acid on birth weight. Research is needed to further our understanding of nutrient-nutrient interactions.     

Weekly may be as efficacious as daily folic acid supplementation in improving folate status and lowering serum homocysteine concentrations in Guatemalan women

Daily folic acid (FA) supplementation improves folate status, lowers circulating homocysteine (Hcy) concentrations, and reduces the risk of neural tube defects. Little is known about the efficacy of weekly FA supplementation. The objective of this study was to compare the efficacy of weekly and daily FA supplementations in improving folate and vitamin B-12 status and lowering Hcy concentrations in healthy reproductive-aged women. A randomized, double-blind supplementation trial was conducted in Guatemala. A total of 459 women were assigned randomly to 4 groups to receive weekly (5000 or 2800 microg) or daily (400 or 200 microg) FA for 12 wk. Daily and weekly iron, zinc, and vitamin B-12 were also provided. We determined serum and RBC folate by microbiological assays, but the latter was available only at baseline. Serum Hcy and vitamin B-12 were also measured. We used generalized linear regression models to assess the effects of treatment on biochemical indicators. Supplementation improved folate status similarly across all 4 groups. Overall, mean serum folate concentrations increased by 15.4 nmol/L (95% CI: 13.8, 16.9) and the geometric mean serum Hcy concentration decreased by 9.8% (95% CI: -12.3, -7.1). Daily supplementation improved serum vitamin B-12 by 20% (95% CI: 8, 33.2), whereas weekly supplementation had no effect. In conclusion, weekly FA (either high or low dose) plus vitamin B-12 may be as efficacious as daily supplementation in improving serum folate and lowering Hcy concentrations in healthy women of reproductive age.     

Lack of hemoglobin response to iron supplementation in anemic mexican preschoolers with multiple micronutrient deficiencies

BACKGROUND: In developing countries, incomplete resolution of anemia with iron supplementation is often attributed to poor compliance or inadequate duration of supplementation, but it could result from deficiencies of other micronutrients. OBJECTIVE: Our objective was to assess children's hematologic response to supervised, long-term iron supplementation and the relation of this response to other micronutrient deficiencies, anthropometry, morbidity, and usual dietary intake. DESIGN: Rural Mexican children aged 18-36 mo (n = 219) were supplemented for 12 mo with either 20 mg Fe, 20 mg Zn, both iron and zinc, or placebo. Children were categorized as iron-unsupplemented (IUS; n = 109) or iron supplemented (IS; n = 108). Hemoglobin, hematocrit, mean corpuscular volume, mean cell hemoglobin, plasma concentrations of micronutrients that can affect hematopoiesis, anthropometry, and diet were assessed at 0, 6, and 12 mo; morbidity was assessed biweekly. RESULTS: At baseline, 70% of children had low hemoglobin (相似文献   

Maternal low-dose vitamin A or beta-carotene supplementation has no effect on fetal loss and early infant mortality: a randomized cluster trial in Nepal

BACKGROUND: The effect of vitamin A supplementation on the survival of infants aged <6 mo is unclear. Because most infant deaths occur in the first few month of life, maternal supplementation may improve infant survival. OBJECTIVES: The objective was to assess the effect of maternal vitamin A or beta-carotene supplementation on fetal loss and survival of infants <6 mo of age. DESIGN: Married women of reproductive age in 270 wards of Sarlahi district, Nepal, were eligible to participate. Wards were randomly assigned to have women receive weekly doses of 7000 microg retinol equivalents as retinyl palmitate (vitamin A), 42 mg all-trans-beta-carotene, or placebo. Pregnancies were followed until miscarriage, stillbirth, maternal death, or live birth of one or more infants, who were followed through 24 wk of age. RESULTS: A total of 43559 women were enrolled; 15832 contributed 17373 pregnancies and 15987 live born infants to the trial. The rate of fetal loss was 92.0/1000 pregnancies in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.06 (95% CI: 0.91, 1.25) and 1.03 (95% CI: 0.87, 1.19), respectively. The 24-wk mortality rate was 70.8/1000 live births in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.05 (95% CI: 0.87, 1.25) and 1.03 (95% CI: 0.86, 1.22), respectively. CONCLUSIONS: Small weekly doses of vitamin A or beta-carotene given to women before conception, during pregnancy, and through 24 wk postpartum did not improve fetal or early infant survival in Nepal.     

Simultaneous weekly supplementation of iron and zinc is associated with lower morbidity due to diarrhea and acute lower respiratory infection in Bangladeshi infants

Given the high prevalence of micronutrient deficiencies and infectious diseases in infants in developing countries, an evaluation of the efficacy of different micronutrient formulations on infant morbidity is a priority. The efficacy of weekly supplementation of four different micronutrient formulations on diarrhea and acute lower respiratory infection (ALRI) morbidity was evaluated in Bangladeshi infants. In a double-blind, randomized, controlled community trial, 799 infants aged 6 mo were randomly assigned to one of the following 5 groups: 1) 20 mg elemental iron with 1 mg riboflavin, 2) 20 mg elemental zinc with 1 mg riboflavin, 3) 20 mg iron and 20 mg zinc with 1 mg riboflavin, 4) a micronutrient mix (MM) containing 20 mg iron, 20 mg zinc, 1 mg riboflavin along with other minerals and vitamins and 5) a control treatment, 1 mg riboflavin only. Health workers visited each infant weekly until age 12 mo to feed the supplement and to collect data on diarrhea and ALRI morbidity. Hemoglobin, serum ferritin and serum zinc levels of a sample of infants were measured at 6 and 12 mo. Compared with the control group, at 12 mo, serum ferritin levels were higher in the iron + zinc group, and serum zinc levels were higher in the zinc and iron + zinc groups. Simultaneous supplementation with iron + zinc was associated with lower risk of severe diarrhea, 19% lower in all infants and 30% lower in less well-nourished infants with weight-for-age Z-score below -1. Iron + zinc supplementation was also associated with 40% lower risk of severe ALRI in less well-nourished infants. MM supplementation was associated with a 15% higher risk of diarrhea in all infants and 22% higher risk in less well-nourished infants. Intermittent simultaneous supplementation with iron + zinc seems promising; it will be useful to determine whether higher doses would provide greater benefits.     

Concomitant supplemental vitamin A enhances the response to weekly supplemental iron and folic acid in anemic teenagers in urban Bangladesh.

BACKGROUND: Iron deficiency is the most common micronutrient deficiency and affects >2 billion persons worldwide, leading to anemia in >40% of women of reproductive age in the developing world. OBJECTIVE: The objective was to determine whether weekly supplementation with iron and folate would reduce the frequency of anemia in teenage women in urban Bangladesh before they became pregnant. DESIGN: Participants with a hemoglobin concentration of 80-120 g/L were entered into a randomized, double-blind, placebo-controlled trial and received supplements of placebo, vitamin A, iron + folic acid, or iron + folic acid + vitamin A weekly for 12 wk. The supplements contained 2.42 mg vitamin A (retinol) as retinyl palmitate, 120 mg elemental Fe as ferrous sulfate, and 3.5 mg folic acid. RESULTS: Hemoglobin concentrations increased significantly more after supplementation with iron + folic acid or iron + folic acid + vitamin A than after either the placebo or vitamin A alone. There was a significantly greater increase in hemoglobin after iron + folic acid + vitamin A than after iron + folic acid, but the additional effect disappeared after adjustment for baseline hemoglobin, serum vitamin A, and ferritin and the number of supplements taken. Those with the lowest baseline hemoglobin had the greatest increase in hemoglobin. Compared with the placebo, iron + folic acid + vitamin A reduced anemia by 92%, iron deficiency by 90%, and vitamin A deficiency by 76%. CONCLUSION: There may be significant health benefits from a program that enhances the nutritional status of iron, folate, and vitamin A in poor urban young women before they become pregnant.     

A micronutrient-fortified beverage prevents iron deficiency,reduces anemia and improves the hemoglobin concentration of pregnant Tanzanian women

Maternal malnutrition continues to be a major contributor to adverse reproductive outcomes in developing countries, despite longstanding efforts to fortify foods or to distribute medicinal supplements to pregnant women. The objective of this study was to test the effect of a micronutrient-fortified beverage containing 11 micronutrients (iron, iodine, zinc, vitamin A, vitamin C, niacin, riboflavin, folate, vitamin B-12, vitamin B-6 and vitamin E) on the hemoglobin, iron and vitamin A status of pregnant women in Tanzania. A group of 259 pregnant women with gestational ages of 8 to 34 wk were enrolled in a randomized double-blind controlled trial in which study women received 8 wk of supplementation. Hemoglobin, ferritin and dried blood spot retinol were measured at baseline and at the end of the supplementation period. The supplement resulted in a 4.16 g/L increase in hemoglobin concentration and a 3 micro g/L increase in ferritin and reduced the risk of anemia and iron deficiency anemia by 51 and 56%, respectively. The risk of iron deficiency was reduced by 70% among those who had iron deficiency at baseline and by 92% among those who had adequate stores. The micronutrient-fortified beverage may be a useful and convenient preventative measure, one that could help improve the nutritional status of women both before and during pregnancy and thereby help avoid some of the potential maternal and fetal consequences of micronutrient deficiencies.     

Home-fortification with iron and zinc sprinkles or iron sprinkles alone successfully treats anemia in infants and young children

Although iron deficiency is the most common single-nutrient deficiency in infants and children, other deficiencies may develop concurrently, including zinc deficiency. In previous studies, we used home-fortification with "Sprinkles," single-serve sachets containing microencapsulated ferrous fumarate added to weaning foods, to successfully treat anemia. This mode of micronutrient delivery is amenable to the delivery of other micronutrients. However, the relative efficacy of multiple micronutrient supplements for the treatment of anemia requires evaluation due to possible nutrient interactions. Thus, we evaluated the relative efficacy of Sprinkles formulated with iron and zinc in anemic infants, compared with Sprinkles formulated with iron alone. We studied 304 anemic infants (mean age 10.3 +/- 2.5 mo; hemoglobin 87.4 +/- 8.4 g/L) in rural Ghana. A combined supplementation group (FeZn) received daily Sprinkles containing 80 mg iron and 10 mg zinc; a comparison group (Fe) received Sprinkles (80 mg iron) without zinc for 2 mo. The rate of recovery from anemia was higher in the Fe group compared with the FeZn group (74.8 vs. 62.9%; P = 0.048). The plasma zinc concentration decreased significantly in both groups (P < 0.05). A significant decline in the height for age Z-score was observed in the FeZn group (P = 0.0011), but there was no change in the Fe group. These results suggest that in a controlled setting, home-fortification using micronutrient Sprinkles with iron, or iron and zinc, was very successful in treating anemia; however, this intervention alone was insufficient to improve zinc status or promote catch-up growth in this stunted and wasted population.     

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.     

Multiple micronutrient supplementation improves anemia, micronutrient nutrient status, and growth of Vietnamese infants: double-blind, randomized, placebo-controlled trial

A randomized, double-blind, placebo-controlled trial was performed to assess the efficacy of different micronutrient supplementation regimes for improving micronutrient status, preventing anemia, and growth faltering of Vietnamese infants. A population-based sample of 306 infants aged 6-12 mo, split in 4 treatment groups, received daily multiple micronutrient (DMM), daily placebo (P), weekly multiple micronutrient (WMM), or daily iron (DI) supplements for 6 mo, 7 d/wk, under supervision. Weight and length were measured monthly, and anemia and plasma levels of ferritin, zinc, riboflavin, retinol, tocopherol, and homocysteine were determined before and after the supplementation. Z-scores for length-for-age and weight-for-age worsened significantly in all groups, but the length-for-age Z-score decreased significantly less in the DMM group (-0.32 +/- 0.05) than in the P and WMM groups (-0.49 +/- 0.05 and -0.51 +/- 0.05, respectively, P = 0.001). Hemoglobin levels increased significantly more in the DMM group [mean (95%CI): 16.4 g/L (12.4-20.4)] than in the P group [8.6 g/L (5.0-12.2), P = 0.04), with intermediate nonsignificant increases in the WMM [15.0 g/L (11.5-18.5)] and the DI [12.9 g/L (8.4-17.3)] groups. Ferritin changes were significantly greater in DMM (12.1 microg/L) and DI (9.5 microg/L) than in P (-14.7 microg/L) and WMM groups (-9.7 microg/L). Of the other micronutrients, only tocopherol showed a significantly greater level in the DMM group compared with P. Anemia still affected a quarter and zinc deficiency affected a third of infants although there was no iron deficiency after 6 mo of supplementation with DMM, suggesting that multiple factors are causing anemia and that the dose of zinc is too small.     

Vitamin and trace element status of women with disordered eating

We studied biochemical measures of vitamin B-6, zinc, and copper in a group of 96 women and vitamin A and vitamin E concentrations in 89 women, all suffering from an eating disorder. Twenty-three control subjects were studied. Eating-disorder patients not taking vitamin or mineral supplements had significantly higher plasma concentrations of vitamins A and E than did control subjects (also not taking supplements). No difference was found in indices indicating vitamin B-6 status or in plasma zinc or copper concentrations. Self-induced vomiting was the only significant predictor of upper-quartile vitamin A concentrations. Upper-quartile vitamin B-6 activations (indicating lower vitamin B-6 activity) were significantly predicted only by low actual body weight. These results suggest that supplementation of micronutrient intake needs only to be considered for those eating-disorder patients at low weight and then only with water-soluble vitamins.     

Multivitamin supplementation of HIV-positive women during pregnancy reduces hypertension

Hypertension during pregnancy increases fetal growth retardation, preterm deliveries, and perinatal deaths, and yet its causes remain unclear. In HIV-infected women, preterm birth additionally increases the risk of HIV transmission to the infant. Oxidative stress and endothelial cell dysfunction of the placenta have been implicated in the development of hypertension during pregnancy. Vitamin intake can reduce oxidative stress and improve endothelial function. We therefore evaluated the effect of multivitamin (20 mg thiamine, 20 mg riboflavin, 25 mg B-6, 50 microg B-12, 500 mg C, 30 mg E, and 0.8 mg folic acid) and vitamin A supplements (30 mg beta-carotene plus 5000 IU preformed vitamin A) in relation to hypertension during pregnancy (systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg at any time during pregnancy). In a double-blind, placebo-controlled, randomized, clinical trial, conducted among 1078 HIV-positive pregnant Tanzanian women, those who received multivitamins were 38% less likely to develop hypertension during pregnancy than those who did not [relative risk (RR) = 0.62, 95% CI 0.40-0.94, P = 0.03]. There was no overall effect of vitamin A on hypertension during pregnancy (RR = 1.00, 95% CI 0.66-1.51, P = 0.98). Hypertension during pregnancy was more likely in women with high baseline systolic blood pressure (>120 vs. < or = 120 mm Hg) (RR = 6.02, 95%CI 2.59-13.97, P < 0.001), and those with higher mid-upper arm circumference (RR = 1.12, 95% CI 1.04-1.19, P = 0.002). Taking multivitamins containing vitamins B, C, and E during pregnancy may be an inexpensive and effective strategy to improve the health of the mother and baby.     

Multiple micronutrient supplementation increases the growth of Mexican infants.

BACKGROUND: The role of single micronutrient deficiencies in the etiology of growth retardation has recently gained attention. However, because multiple micronutrient deficiencies are common in children in developing countries, it is possible that more than one micronutrient may limit growth and, hence, the correction of a single deficiency may not be enough to improve growth substantially. OBJECTIVE: The objective was to evaluate the effect of multiple micronutrient supplementation on the growth of children aged 8-14 mo whose diets were poor in several micronutrients. DESIGN: Children were randomly assigned to 1 of 2 groups. One group received a multiple micronutrient supplement containing the recommended dietary allowance (RDA) or 1.5 times the RDA of vitamins A, D, E, K, C, B-1, B-6, B-12, riboflavin, niacin, biotin, folic acid, and pantothenic acid, and iron, zinc, iodine, copper, manganese, and selenium. The other group received a placebo. Supplements were administered 6 d/wk for an average of 12.2 mo. Body length was measured at baseline and monthly thereafter until the end of supplementation. RESULTS: Supplemented infants initially aged <12 mo had significantly greater length gains than did the placebo group, with a difference of 8.2 mm (length-for-age z score: 0.3) at the end of supplementation. In contrast, differences in length gains between the supplemented and placebo groups initially aged > or =12 mo were not significant. CONCLUSIONS: Micronutrient deficiencies limited the growth of the Mexican infants studied. Improving micronutrient intakes should be a component of interventions to promote growth in infants living in settings where micronutrient intakes are inadequate.