Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “micronutrient”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2006

The key role of micronutrients.

Micronutrients play a central role in metabolism and in the maintenance of tissue function, but effects in preventing or treating disease which is not due to micronutrient deficiency cannot be expected from increasing the intake. There is a highly integrated system to control the flux of micronutrients in illness, and this demonstrates just how important the body perceives the micronutrients to be. An adequate intake therefore is necessary to sustain metabolism and tissue function, but provision of excess supplements to individuals who do not need them may be harmful. Clinical benefit is most likely in those individuals who are severely depleted and at risk of complications, and is unlikely if this is not the case. Much more research is needed to characterise better markers of micronutrient status both in terms of metabolic effects and antioxidant effects, so that at-risk patients can be identified and supplementation modified accordingly. Large-scale trials of different doses of micronutrients are required with precise outcome markers to optimise intakes in different groups of patients as well as in the general population.

Antioxidants↗
PubMed2005

Micronutrient status and fertilizer use scenario in India.

India was dependent on external food supplies in the early 1960s. To meet the growing demand for food, fiber and fuel, high yielding cultivars were introduced. These high yielding crop cultivars were highly responsive to fertilizers. Thus, slowly the soils were exhausted of their nutrients. Application of major nutrients (nitrogen, phosphorus, potassium) became common, therefore the crops started responding to micronutrient fertilizers. Concerted efforts have been made through the All India Coordinated Research Project on Micronutrients to delineate the soils of India regarding the deficiency of micronutrients. At present about 48.1% of Indian soils are deficient in diethylene-triaminepentaacetate (DTPA) extractable zinc, 11.2% in iron, 7% in copper and 5.1% in manganese. Apart from the deficiency of these micronutrients, deficiencies of boron and molybdenum have also been reported in some areas. Areas with multi-micronutrient deficiencies are limited, thus simple fertilizers are sufficient to exploit the potential of crops and cropping systems. Based on the extent of deficiency, cultivated area, and crop removal, the micronutrient fertilizer demand in 2025 is projected using sufficiency and maintenance approaches.

Fertilizers↗
PubMed2006

Effect of micronutrient supplement on health and nutritional status of schoolchildren: study design.

OBJECTIVE: We tested the hypothesis that supplementation with a micronutrient-fortified beverage improves micronutrient status and physical and mental development in apparently healthy schoolchildren. METHODS: The study was carried out in middle-income students in two residential schools that catered to children from a semi-urban population near Hyderabad, India. Included were 869 children who were 6 to 16 y of age in grades 1 to 10. Because children at each grade were distributed across two classrooms (clusters) and were homogeneous, each grade was considered to consist of a matched pair. There were thus 10 pairs available for the study. Classes in each grade were randomized to receive a micronutrient-enriched beverage or a placebo without added micronutrients. The study was double blinded and the duration was 14 mo, with supervised feeding of the micronutrient-enriched beverage. The effect of the micronutrients on the outcome variables growth, biochemical status, mental function, and bone health were assessed. RESULTS: The number of matched pairs varied between seven and eight, and the required number of children per treatment group ranged from 32 in the case of bone heath to 177 for body weight. The power of the outcome variables ranged from 74% to 100% and was adequate for successful pairing. The effect assessed at the end of supplementation showed that the intervention was beneficial. CONCLUSIONS: Designing an intervention, choosing outcome variables, and implementing the protocol in a typical Indian school setting were achieved.

Adolescent↗
PubMed2006

Effect of micronutrient supplement on health and nutritional status of schoolchildren: biochemical status.

OBJECTIVE: We assessed the effect of a daily intake of a micronutrient-fortified beverage for 14 mo on indicators of biochemical status of important micronutrients in schoolchildren. METHODS: A double-blind, placebo-controlled, matched-pair, cluster, randomization study design was used. Biochemical indicators of micronutrient status were evaluated at baseline and at the end of 14 mo on a subsample in nine matched pairs. Prevalence (percentage) of subclinical deficiency, mean, and mean increments of each indicator were compared between supplemented and placebo groups. RESULTS: Extent of inadequacy at baseline was more or less 100% for folic acid, 65% for vitamins B2 and B6, and 55% for vitamins C and A. Prevalence of anemia among subjects was 55%, with inadequacy of vitamin B12 being 40% and that of vitamin D being 30%. No subject had inadequacy of iodine based on urinary iodine. Supplementation of a micronutrient-enriched beverage for 14 mo significantly improved the status of many of the nutrients. The effect was significant with respect to vitamins A, B2, and B12, folic acid, vitamin D, parathyroid hormone, and thyroid-stimulating hormone in children who received the supplement compared with those who received only placebo. Hemoglobin status improved only in children who had anemia in the supplemented group. CONCLUSIONS: Prevalence of multiple subclinical micronutrient deficiencies are high in middle-income Indian school children. Daily consumption of a micronutrient-enriched beverage had positive effects that were confined to those nutrients that were inadequate at baseline.

Adolescent↗
PubMed2002

Micronutrient malnutrition and the pathogenesis of malarial anemia.

Malaria is a leading cause of morbidity and mortality worldwide, and anemia is a common and sometimes serious complication of Plasmodium falciparum infection. Although micronutrient malnutrition is usually highly prevalent in malaria endemic areas, the contribution of micronutrient deficiencies to malarial anemia is often overlooked. Recent investigation suggests that micronutrients such as vitamin A, vitamin E, and zinc, may improve the morbidity of malaria through immune modulation and alteration of oxidative stress. Micronutrients are also involved in the pathogenesis of anemia and likely play a role in malarial anemia, but many clinical trials have not specifically addressed the impact of micronutrient supplementation on malarial anemia. Further work is needed to assess the effect of both clinic and community-based micronutrient interventions on malarial anemia in infants, children, and pregnant women.

Adolescent↗
PubMed1999

Micronutrients and the pathogenesis of human immunodeficiency virus infection.

Micronutrient deficiencies may be common during human immunodeficiency virus (HIV) infection. Insufficient dietary intake, malabsorption, diarrhoea, and impaired storage and altered metabolism of micronutrients can contribute to the development of micronutrient deficiencies. Low plasma or serum levels of vitamins A, E, B6, B12 and C, carotenoids, Se, and Zn are common in many HIV-infected populations. Micronutrient deficiencies may contribute to the pathogenesis of HIV infection through increased oxidative stress and compromised immunity. Low levels or intakes of micronutrients such as vitamins A, E, B6 and B12, Zn and Se have been associated with adverse clinical outcomes during HIV infection, and new studies are emerging which suggest that micronutrient supplementation may help reduce morbidity and mortality during HIV infection.

Avitaminosis↗
PubMed2001

Dietary sugars and micronutrient dilution in normal adults aged 65 years and over.

OBJECTIVE: To examine the relationship between non-milk extrinsic sugars (NMES) concentration and micronutrient intakes and status in free-living older people. DESIGN: The National Diet and Nutrition Survey of people aged 65 years and over; a cross-sectional study in Britain in 1994/5. SUBJECTS AND METHODS: Eight hundred and six men and women living in private households who were not on medication for nutritional disorders. Subjects were classified into four groups (Q1 to Q4), using cut-off points corresponding to quartiles of energy from NMES. Relationships were examined between dietary NMES concentration and intakes of calcium, iron, riboflavin, folate, vitamin C and vitamin D. Status indices were also assessed in each group. RESULTS: Overall, a small proportion of men and women had intakes below the Lower Reference Nutrient Intake (LRNI) for calcium, iron, folate, riboflavin or vitamin C, while vitamin D intakes were universally low. Intakes of micronutrients tended to be highest at moderate levels of NMES in the diet (Q2 and Q3, equivalent to 8-15% of energy from NMES). Micronutrient status was low for riboflavin in 38% of the sample, while 15% had low vitamin C status and more than 10% were anaemic. There was little evidence that poorer nutrient status was associated with higher levels of dietary NMES. Although some indices of folate status were lower in Q4, this is most likely to reflect confounding by smoking. Energy intake accounted for 20-40% of the variance in micronutrient intakes, compared with less than 5% for NMES concentration. CONCLUSIONS: A diet moderately high in NMES (up to around 15% of energy) is unlikely to have a detrimental impact on micronutrient intake or status in this age group. Energy intake is the major determinant of micronutrient adequacy.

Aged↗
PubMed2002

Disadvantaged black and coloured infants in two urban communities in the Western Cape, South Africa differ in micronutrient status.

OBJECTIVES: To determine the nutritional and health status of urban infants in two disadvantaged communities in the Western Cape, South Africa with special reference to micronutrient status. The results of this study will serve to plan an intervention study in these communities in the same age group. DESIGN: Cross-sectional study. SETTING: Two disadvantaged urban black and 'coloured' communities in the Western Cape, South Africa. SUBJECTS: Sixty infants aged 6-12 months from each community. OUTCOME MEASURES: Dietary intake, anthropometric measurements, micronutrient status and psychomotor development. RESULTS: Stunting and underweight were more prevalent in coloured infants (18% and 7%, respectively) than in black infants (8% and 2%, respectively). Anaemia (haemoglobin (Hb) < 11 g dl(-1) was prevalent in 64% of coloured and 83% of black infants. Iron-deficiency anaemia (Hb < 11 g dl(-1) and ferritin < 10 ng ml(-1) was found in 32% of coloured infants and in 46% of black infants. Zinc deficiency was prevalent in 35% and 33% of the coloured and black infants, respectively. Marginal vitamin A deficiency (serum retinol < 20 microg dl(-1) was observed in 23% of black infants compared with 2% of coloured infants. Of black infants, 43% and of coloured infants 6% were deficient in two or more micronutrients. Six per cent of coloured infants had C-reactive protein concentrations above 5 mg l(-1) compared with 38% of the black infants. The dietary intake of micronutrients was in general lower in black infants than in coloured infants. The overall psychomotor development, assessed by the Denver Developmental Screening Test, was different between the two groups. The coloured infants scored higher in three out of the four categories as well as in their overall score. CONCLUSIONS: This study shows that information on stunting and wasting only in urban disadvantaged infants is not sufficient to make recommendations about specific community intervention programmes. Information on the micronutrient status, independent of wasting and stunting, is necessary to design nutrition programmes for different communities. The study also showed a substantially higher prevalence of micronutrient deficiencies among black infants.

Black or African American↗
PubMed2003

Impact of ready-to-eat breakfast cereal (RTEBC) consumption on adequacy of micronutrient intakes and compliance with dietary recommendations in Irish adults.

OBJECTIVE: To describe the consumption of ready-to-eat-breakfast cereals (RTEBCs) in Irish adults and its impact on adequacy and safety of micronutrient intakes and compliance with dietary recommendations. DESIGN: Analysis for this paper used data from the North/South Ireland Food Consumption Survey that estimated habitual food intake using a 7-day food diary in a representative sample of adults aged 18-64 years ( 662 men, 717 women). RESULTS: Despite the small quantity consumed (mean 28.6 g day-1 or 4.7% of total energy intake), RTEBCs made an important contribution to the mean daily intake of carbohydrate (8.1%), starch (10.8%), dietary fibre (9.8%) and non-starch polysaccharides (NSP) (10.8%) in consumers. Increased consumption was associated with a more fibre-dense diet and with greater compliance with dietary recommendations for fat, carbohydrate and NSP. Fortified RTEBCs contributed significantly to mean daily intakes of iron (18%), thiamin (14%), riboflavin (17%), niacin (15%), vitamin B6 (13%), total folate (18%) and vitamin D (10%) and most of the contribution was from micronutrients added to RTEBCs. Increased consumption of fortified RTEBCs was associated with an increased nutrient density for a number of micronutrients and with a lower prevalence of dietary inadequacy of calcium, iron, riboflavin and folate, particularly in women. However, it was not associated with intakes in excess of the Tolerable Upper Intake Level for any micronutrient. CONCLUSIONS: The consumption of RTEBCs is associated with improved compliance with dietary recommendations for fat, carbohydrate and fibre, with a more micronutrient-dense diet and a reduced risk of dietary inadequacy for calcium, iron, riboflavin and folate, without increasing the risk of excessive intakes of micronutrients.

Adolescent↗
PubMed2005

Micronutrients in childhood and the influence of subclinical inflammation.

In the present paper biomarkers of micronutrient status in childhood and some of the factors influencing them, mainly dietary intake, requirements and inflammation will be examined. On a body-weight basis the micronutrient requirements of children are mostly higher than those of an adult, but most biomarkers of status are not age-related. A major factor that is often overlooked in assessing status is the influence of subclinical inflammation on micronutrient biomarkers. In younger children particularly the immune system is still developing and there is a higher frequency of sickness than in adults. The inflammatory response rapidly influences the concentration in the blood of several important micronutrients such as vitamin A, Fe and Zn, even in the first 24 h, whereas dietary deficiencies can be envisaged as having a more gradual effect on biomarkers of nutritional status. The rapid response to infection may be for protective reasons, i.e. conservation of reserves, or by placing demands on those reserves to mount an effective immune response. However, because there is a high prevalence of disease in many developing countries, an apparently-healthy child may well be at the incubation stage or convalescing when blood is taken for nutritional assessment and the concentration of certain micronutrient biomarkers will not give a true indication of status. Most biomarkers influenced by inflammation are known, but often they are used because they are convenient or cheap and the influence of subclinical inflammation is either ignored or overlooked. The objective of the present paper is to discuss: (1) some of the important micronutrient deficiencies in childhood influenced by inflammation; (2) ways of correcting the interference from inflammation.

Adolescent↗
PubMed1997

A preliminary report: effects of zinc and micronutrient repletion on growth and neuropsychological function of urban Chinese children.

OBJECTIVE: Zinc is essential for growth and cognition of experimental animals. Past research found zinc repletion improved growth of stunted Chinese children. Therefore we measured effects of zinc repletion on growth and neuropsychological functions of children. DESIGN: Double-blind randomized controlled treatment trial. SETTING: Elementary schools in low income districts of Chongqing, Qingdao and Shanghai. SUBJECTS: Three hundred-seventy-two 6 to 9 year old first graders. INTERVENTIONS: Treatments were 20 mg zinc, 20 mg zinc with micronutrients, or micronutrients alone. The micronutrient mixture was based on guidelines of the US NAS/NRC. Treatments were assigned to classrooms of 40 or more children each, and administered by teachers 6 days per week for 10 weeks. MEASURES OF OUTCOME: Changes in knee height and neuropsychological functions. RESULTS: Zinc alone had the least effect on growth while zinc with micronutrients had the largest effect; micronutrients alone had an intermediate effect. Zinc-containing treatments improved neuropsychological functions, but micronutrients alone had little effect. CONCLUSIONS: The findings confirm the essentiality of zinc for growth of children, and show, for the first time, the essentiality of zinc for neuropsychological functions of children. In addition, the need for repletion of other potentially limiting nutrients in studies examining the effects of specific nutrients on growth and neuropsychological functions was confirmed.

Analysis of Variance↗
PubMed2000

Effect of micronutrient status on natural killer cell immune function in healthy free-living subjects aged >/=90 y.

BACKGROUND: Natural killer (NK) cells play a role in natural immunity against tumor and infected cells. Advanced aging is associated with functional impairment of NK cells and increased susceptibility to nutritional deficiencies. OBJECTIVE: Our objective was to test whether micronutrient status affects NK cell activity in an older population. DESIGN: The relations between NK cell variables (percentage of leukocytes and cytotoxicity) and blood concentrations of selected micronutrients were studied in 62 healthy, free-living northern Italian subjects (25 men, 37 women) aged 90-106 y. Anthropometric measurements were also made. RESULTS: All subjects were well nourished according to age-specific anthropometric norms but many of them had micronutrient deficiencies. The prevalence of micronutrient deficiency was highest for selenium (in approximately 50% of both sexes), zinc (in 52% of men and 41% of women), and vitamin B-6 (in 40% of men and 59% of women), followed by vitamin A (in 16% of men and 27% of women) and vitamin E, vitamin B-12, and folate (each in <10% of both sexes). Ubiquinone-10 status was inadequate in 40% of women and 24% of men (P = 0.02). The percentage of NK cells was associated with serum zinc (men: r = 0.573, P = 0. 007; women: r = 0.373, P = 0.031) and selenium (women: r = 0.409, P = 0.018) concentrations. In women only, NK cell cytotoxicity at different effector-target cell ratios was positively associated with plasma vitamin E and ubiquinone-10 concentrations (P < 0.05). No significant associations with NK cell variables were found for the other measured nutrients. CONCLUSIONS: The results of this study strengthen the hypothesis that individual micronutrients may affect the number and function of NK cells in old age. The study also confirms the high prevalence of micronutrient deficiencies in healthy and apparently well-nourished persons aged >/=90 y.

Adult↗
PubMed2005

Multiple micronutrients in pregnancy and lactation: an overview.

This overview of multiple micronutrients during pregnancy and lactation emphasizes 2 relatively neglected issues. The first is that maternal micronutrient status in the periconceptional period, and throughout pregnancy and lactation, should be viewed as a continuum; too often these 3 stages are treated and discussed separately from both a scientific and a public health perspective. Iron and vitamin B-12 are included as examples to stress how status at conception affects maternal, fetal, and infant status and health until the child is weaned. The second issue is that while most attention has been focused on a few micronutrients, for example iron and folate as discussed elsewhere in this Supplement, multiple micronutrient deficiencies occur simultaneously when diets are poor. Some of these deserve more attention as causes of poor pregnancy outcome, including other B vitamin deficiencies that result in homocysteinemia, antioxidants, vitamin D, and iodine. In lactation, maternal status or intake of the B vitamins (except folate), vitamin A, selenium and iodine strongly affect the amount of these nutrients secreted in breast milk. This can result in the infant consuming substantially less than the recommended amounts and further depleting stores that were low at birth. While the optimal mode of meeting recommended micronutrient intakes is an adequate diet, in some situations supplementation is also important. Unfortunately, information is lacking on the optimal formulation of micronutrient supplements for pregnant women, and the need to continue these supplements during lactation is not recognized in many situations where maternal and infant health could benefit.

Anemia, Iron-Deficiency↗
PubMed2005

The effect of micronutrient supplementation on quality-of-life and left ventricular function in elderly patients with chronic heart failure.

AIMS: Chronic heart failure (CHF) is a common and leading cause of death in industrialized countries. The potential benefits of micronutrient supplementation in CHF are extensive. Therefore, we examined the influence of long-term multiple micronutrient supplementation on left ventricular (LV) function, levels of pro-inflammatory cytokines, and quality-of-life (QoL) in elderly patients with CHF. METHODS AND RESULTS: Thirty CHF patients [age 75.4 (0.7), mean (SEM), LV ejection fraction (LVEF) < or =35%] were randomized to receive capsules containing a combination of high-dose micronutrients (calcium, magnesium, zinc, copper, selenium, vitamin A, thiamine, riboflavin, vitamin B(6), folate, vitamin B(12), vitamin C, vitamin E, vitamin D, and Coenzyme Q10) or placebo for 9 months in a double-blind fashion. All subjects were on stable optimal medical therapy for at least 3 months before enrolment. At randomization and at study end, tumour necrosis factor-alpha and its soluble receptors TNFR-1 and TNFR-2 were measured and six-minute walk test and QoL were assessed. Cardiac magnetic resonance scanning was performed to evaluate cardiac dimensions and LVEF. Two patients died during follow-up. The remaining patients (14 randomized to placebo and 14 to micronutrients) were well matched for LV function, symptoms, and exercise capacity. At the end of the follow-up period, LV volumes were reduced in the intervention group with no change in the placebo group [-13.1 (17.1)% vs. +3.8 (10.0)%; P<0.05]. LVEF increased by 5.3+/-1.4% in the intervention group and was unchanged in the placebo group (P<0.05). Patients taking micronutrients also had a significant improvement in QoL score between enrolment and study end [+9.5 (1.6)%; P<0.05], whereas those taking placebo had a slight deterioration [-1.1 (0.8)%; P=0.12]. Six-minute walk test and inflammatory cytokine levels remained unchanged in both groups. CONCLUSION: Long-term multiple micronutrient supplementation can improve LV volumes and LVEF and QoL scores in elderly patients with heart failure due to LV systolic dysfunction.

Aged↗
PubMed1999

Separate and joint effects of micronutrient deficiencies on linear growth.

Recent studies have investigated the effect of micronutrient deficiencies on growth stunting, with special attention toward the effect of zinc, iron, vitamin A and iodine deficiencies. In Mexico, the prevalence of growth stunting in children <5 y old is approximately 24%; it is higher in rural areas and lower in urban areas. In an initial study, the effect of zinc and/or iron supplementation on linear growth was investigated in a longitudinal, placebo-controlled design. After 12 mo of supplementation, there was no difference between the groups supplemented with zinc, iron or zinc plus iron and the placebo group. At baseline, 82% of the children in this study were deficient in at least two out of the five micronutrients that were determined, and 73% were anemic. In another study, a mixture of those micronutrients that were documented to be lacking in Mexican children was formulated in a supplement and given to Mexican children over a period of 12 mo in a longitudinal, placebo-controlled, supplementation design. Children in the low and medium socioeconomic status grew about 1 cm more than similar children in the placebo group. This difference was not found in children of high socioeconomic status. It is suggested that, in most cases, growth stunting is associated with marginal deficiencies of several micronutrients and that in populations with multiple micronutrient deficiencies, the effect on linear growth of supplementation with single nutrients will not be significant. Supplementation with multiple micronutrients is expected to be more effective, but even in that case the actual increment in height was less than the expected potential increment.

Child, Preschool↗
PubMed2003

Supplementation with micronutrients in addition to iron and folic acid does not further improve the hematologic status of pregnant women in rural Nepal.

Iron deficiency is one of the main causes of anemia during pregnancy, although other micronutrient deficiencies may play a role. We examined the effects of daily antenatal and postnatal supplementation with four combinations of micronutrients on maternal hematologic indicators in a double-masked randomized controlled community trial. Communities, called sectors, were randomly assigned to supplementation with folic acid (400 microg), folic acid plus iron (60 mg), folic acid plus iron and zinc (30 mg) and folic acid plus iron, zinc and 11 other micronutrients, each at the approximate recommended daily allowance for pregnancy all given with vitamin A as retinol acetate (1000 microg retinol equivalent), or vitamin A alone as the control group. Hemoglobin (Hb) and indicators of iron status were assessed at baseline and at 32 wk of gestation. At 6-wk postpartum, Hb assessment was repeated using a finger stick. Severely anemic women (Hb < 70 g/L) were treated according to WHO recommendations. Folic acid alone had no effect on maternal anemia or iron status. Hb concentrations were 14 g/L, [95% confidence limits (CL), 8.3-19.2], 10.0 g/L (CL, 5.2-14.8) and 9.4 g/L (CL, 4.7-14.1) higher in the groups receiving folic acid plus iron, folic acid plus iron and zinc and folic acid plus iron, zinc and multiple micronutrients, respectively, relative to the control. Anemia in the third trimester was reduced by 54% with folic acid plus iron, by 48% with folic acid plus iron and zinc and by 36% with folic acid plus iron, zinc and multiple micronutrients supplementation, relative to the control (P < 0.05). Thus, the combinations of folic acid plus iron and zinc and folic acid plus iron, zinc and multiple micronutrients provided no additional benefit in improving maternal hematologic status during pregnancy compared with folic acid plus iron. The level of compliance and baseline Hb concentrations modified the effect of iron.

Dietary Supplements↗
PubMed2003

Assessing micronutrient status in the presence of inflammation.

Measurement of micronutrient status in the presence of inflammation is difficult for several reasons. Changes in levels of acute phase proteins are associated with increased plasma levels of some indicators of micronutrient status, such as ferritin, and decrease of others, such as retinol. Alterations in the plasma levels of acute phase proteins can occur from hemodilution, sequestration and increased or decreased rates of synthesis and breakdown. How much these relate to functional deficiency is not known. Assays that are less perturbed by inflammation, such as the transferrin receptor assay, and adjustment of plasma micronutrient levels according to different cutoff levels for acute phase proteins are helpful but they do not enable precise assessment of micronutrient status among individuals who are infected. Improving assessment of micronutrient status is important if micronutrient interventions are to be targeted to those with the greatest need.

Acute-Phase Proteins↗
PubMed2003

Micronutrients and fetal growth.

Fetal undernutrition affects large numbers of infants in developing countries, with adverse consequences for their immediate survival and lifelong health. It manifests as intrauterine growth retardation (IUGR), defined as birth weight <10th percentile, which probably underestimates the number failing to achieve full growth potential. Birth weight is a crude measure of the dynamic process of fetal growth and does not capture effects of fetal undernutrition on body composition and the development of specific tissues. The link between maternal nutrition and fetal nutrition is indirect. The fetus is nourished by a complex supply line that includes the mother's diet and absorption, endocrine status and metabolism, cardiovascular adaptations to pregnancy and placental function. Micronutrients are essential for growth, and maternal micronutrient deficiency, frequently multiple in developing countries, may be an important cause of IUGR. Supplementation of undernourished mothers with micronutrients has several benefits but there is little hard evidence of improved fetal growth. However, this has been inadequately tested. Most trials have only used single micronutrients and many were inconclusive because of methodological problems. Several food-based studies (some uncontrolled) suggest benefits from improving maternal dietary quality with micronutrient-dense foods. One trial of a multivitamin supplement (HIV-positive mothers, Tanzania) showed increased birth weight and fewer fetal deaths. Well-conducted randomized controlled trials of adequate sample size and including measures of effectiveness are needed in populations at high risk of micronutrient deficiency and IUGR and should include food-based interventions and better measurements of fetal growth, maternal metabolism, and long-term outcomes in the offspring.

Developing Countries↗