Sanitation and Multiple Micronutrient Supplementation in Pregnancy Outcomes: Literature Review

BACKGROUND: Around 2.6 billion people lack proper sanitation. In addition, nutritional problems such as multiple micronutrient (MMN) deficiency can increase morbidity, mortality, and impaired neurocognitive growth at later stages of life. In addition to the need for a sanitary approach, a globally applicable strategy to prevent micronutrient deficiencies in pregnant women, UNICEF recommends the use of MMN for prenatal supplementation as an initial program in developing countries, to reduce the risk of poor birth outcomes. AIM: The aim of this literature study was to analyze the relationship between sanitation and the multimicronutrient (MMN) approach in pregnancy and birth outcomes. METHODS: This research was conducted using literature review method. Various references were collected from online database including reports, journals, and books. The journals were mostly from the scholarly journals. The articles were screened according to the research objectives. The keywords used are sanitation, pregnancy, and multiple micronutrient approach. RESULTS: Several studies have shown that sanitation and the multi micronutrient (MMN) approach play a role in determining pregnancy outcomes. We conclude that the importance of sanitation on pregnancy outcome is to reduce the chance of infection. The importance of MMN in pregnancy outcomes is that mothers who consume MMN during pregnancy can reduce the risk of poor birth output. The role of stakeholders is needed in the future. CONCLUSIONS: Several studies have shown that sanitation and multi micronutrient (MMN) play a role in determining pregnancy outcome.

Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review

Background

Almost two billion people who are deficient in vitamins and minerals are women and children in low- and middle-income countries (LMIC). These deficiencies are worsened during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child. To reduce micronutrient deficiencies, several strategies have been implemented, including diet diversification, large-scale and targeted fortification, staple crop bio-fortification and micronutrient supplementation.

Objectives

To evaluate and summarize the available evidence on the effects of micronutrient supplementation during pregnancy in LMIC on maternal, fetal, child health and child development outcomes. This review will assess the impact of single micronutrient supplementation (calcium, vitamin A, iron, vitamin D, iodine, zinc, vitamin B12), iron-folic acid (IFA) supplementation, multiple micronutrient (MMN) supplementation, and lipid-based nutrient supplementation (LNS) during pregnancy.

Search Methods

We searched papers published from 1995 to 31 October 2019 (related programmes and good quality studies pre-1995 were limited) in CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, Embase, International Initiative for Impact Evaluations, LILACS, Medline, POPLINE, Web of Science, WHOLIS, ProQuest Dissertations & Theses Global, R4D, WHO International Clinical Trials Registry Platform. Non-indexed grey literature searches were conducted using Google, Google Scholar, and web pages of key international nutrition agencies.

Selection Criteria

We included randomized controlled trials (individual and cluster-randomized) and quasi-experimental studies that evaluated micronutrient supplementation in healthy, pregnant women of any age and parity living in a LMIC. LMIC were defined by the World Bank Group at the time of the search for this review. While the aim was to include healthy pregnant women, it is likely that these populations had one or more micronutrient deficiencies at baseline; women were not excluded on this basis.

Data Collection and Analysis

Two authors independently assessed studies for inclusion and risk of bias, and conducted data extraction. Data were matched to check for accuracy. Quality of evidence was assessed using the GRADE approach.

Main Results

A total of 314 papers across 72 studies (451,723 women) were eligible for inclusion, of which 64 studies (439,649 women) contributed to meta-analyses. Seven studies assessed iron-folic acid (IFA) supplementation versus folic acid; 34 studies assessed MMN vs. IFA; 4 studies assessed LNS vs. MMN; 13 evaluated iron; 13 assessed zinc; 9 evaluated vitamin A; 11 assessed vitamin D; and 6 assessed calcium. Several studies were eligible for inclusion in multiple types of supplementation. IFA compared to folic acid showed a large and significant (48%) reduction in the risk of maternal anaemia (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66; studies = 5; participants = 15,540; moderate-quality evidence). As well, IFA supplementation demonstrated a smaller but significant, 12% reduction in risk of low birthweight (LBW) babies (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). MMN supplementation was defined as any supplement that contained at least 3 micronutrients. Post-hoc analyses were conducted, where possible, comparing the differences in effect of MMN with 4+ components and MMN with 3 or 4 components. When compared to iron with or without FA, MMN supplementation reduced the risk of LBW by 15% (average RR 0.85, 95% CI 0.77 to 0.93; studies = 28; participants = 79,972); this effect was greater in MMN with >4 micronutrients (average RR 0.79, 95% CI 0.71 to 0.88; studies = 19; participants = 68,138 versus average RR 1.01, 95% CI 0.92 to 1.11; studies = 9; participants = 11,834). There was a small and significant reduction in the risk of stillbirths (average RR 0.91; 95% CI 0.86 to 0.98; studies = 22; participants = 96,772) and a small and significant effect on the risk of small-for-gestational age (SGA) (average RR 0.93; 95% CI 0.88 to 0.98; studies = 19; participants = 52,965). For stillbirths and SGA, the effects were greater among those provided MMN with 4+ micronutrients. Children whose mothers had been supplemented with MMN, compared to IFA, demonstrated a 16% reduced risk of diarrhea (average RR 0.84; 95% CI 0.76 to 0.92; studies = 4; participants = 3,142). LNS supplementation, compared to MMN, made no difference to any outcome; however, the evidence is limited. Iron supplementation, when compared to no iron or placebo, showed a large and significant effect on maternal anaemia, a reduction of 47% (average RR 0.53, 95% CI 0.43 to 0.65; studies = 6; participants = 15,737; moderate-quality evidence) and a small and significant effect on LBW (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). Zinc and vitamin A supplementation, each both compared to placebo, had no impact on any outcome examined with the exception of potentially improving serum/plasma zinc (mean difference (MD) 0.43 umol/L; 95% CI -0.04 to 0.89; studies = 5; participants = 1,202) and serum/plasma retinol (MD 0.13 umol/L; 95% CI -0.03 to 0.30; studies = 6; participants = 1,654), respectively. When compared to placebo, vitamin D supplementation may have reduced the risk of preterm births (average RR 0.64; 95% CI 0.40 to 1.04; studies = 7; participants = 1,262), though the upper CI just crosses the line of no effect. Similarly, calcium supplementation versus placebo may have improved rates of pre-eclampsia/eclampsia (average RR 0.45; 95% CI 0.19 to 1.06; studies = 4; participants = 9,616), though the upper CI just crosses 1.

Authors' Conclusions

The findings suggest that MMN and vitamin supplementation improve maternal and child health outcomes, including maternal anaemia, LBW, preterm birth, SGA, stillbirths, micronutrient deficiencies, and morbidities, including pre-eclampsia/eclampsia and diarrhea among children. MMN supplementation demonstrated a beneficial impact on the most number of outcomes. In addition, MMN with >4 micronutrients appeared to be more impactful than MMN with only 3 or 4 micronutrients included in the tablet. Very few studies conducted longitudinal analysis on longer-term health outcomes for the child, such as anthropometric measures and developmental outcomes; this may be an important area for future research. This review may provide some basis to guide continual discourse around replacing IFA supplementation with MMN along with the use of single micronutrient supplementation programs for specific outcomes.

Intermittent iron supplementation for reducing anaemia and its associated impairments in adolescent and adult menstruating women

BACKGROUND

Anaemia is a condition in which the number of red blood cells is insufficient to meet physiologic needs; it is caused by many conditions, particularly iron deficiency. Traditionally, daily iron supplementation has been a standard practice for preventing and treating anaemia. However, its long-term use has been limited, as it has been associated with adverse side effects such as nausea, constipation, and teeth staining. Intermittent iron supplementation has been suggested as an effective and safer alternative to daily iron supplementation for preventing and reducing anaemia at the population level, especially in areas where this condition is highly prevalent.

OBJECTIVES

To assess the effects of intermittent oral iron supplementation, alone or in combination with other nutrients, on anaemia and its associated impairments among menstruating women, compared with no intervention, a placebo, or daily supplementation.

SEARCH METHODS

In February 2018, we searched CENTRAL, MEDLINE, Embase, nine other databases, and two trials registers. In March 2018, we also searched LILACS, IBECS and IMBIOMED. In addition, we examined reference lists, and contacted authors and known experts to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs with either individual or cluster randomisation. Participants were menstruating women; that is, women beyond menarche and prior to menopause who were not pregnant or lactating and did not have a known condition that impeded the presence of menstrual periods. The intervention was the use of iron supplements intermittently (one, two or three times a week on non-consecutive days) compared with placebo, no intervention, or the same supplements provided on a daily basis.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed the eligibility of studies against the inclusion criteria, extracted data from included studies, checked data entry for accuracy, assessed the risk of bias of the included studies, and rated the quality of the evidence using GRADE.

MAIN RESULTS

We included 25 studies involving 10,996 women. Study methods were not well described in many of the included studies and thus assessing risk of bias was difficult. The main limitations of the studies were lack of blinding and high attrition. Studies were mainly funded by international organisations, universities, and ministries of health within the countries. Approximately one third of the included studies did not provide a funding source.Although quality across studies was variable, the results consistently showed that intermittent iron supplementation (alone or with any other vitamins and minerals) compared with no intervention or a placebo, reduced the risk of having anaemia (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.49 to 0.87; 11 studies, 3135 participants; low-quality evidence), and improved the concentration of haemoglobin (mean difference (MD) 5.19 g/L, 95% CI 3.07 to 7.32; 15 studies, 2886 participants; moderate-quality evidence), and ferritin (MD 7.46 μg/L, 95% CI 5.02 to 9.90; 7 studies, 1067 participants; low-quality evidence). Intermittent regimens may also reduce the risk of having iron deficiency (RR 0.50, 95% CI 0.24 to 1.04; 3 studies, 624 participants; low-quality evidence), but evidence was inconclusive regarding iron deficiency anaemia (RR 0.07, 95% CI 0.00 to 1.16; 1 study, 97 participants; very low-quality evidence) and all-cause morbidity (RR 1.12, 95% CI 0.82 to 1.52; 1 study, 119 participants; very low-quality evidence). Women in the control group were less likely to have any adverse side effects than those receiving intermittent iron supplements (RR 1.98, 95% CI 0.31 to 12.72; 3 studies, 630 participants; moderate-quality evidence).In comparison with daily supplementation, results showed that intermittent supplementation (alone or with any other vitamins and minerals) produced similar effects to daily supplementation (alone or with any other vitamins and minerals) on anaemia (RR 1.09, 95% CI 0.93 to 1.29; 8 studies, 1749 participants; moderate-quality evidence). Intermittent supplementation may produce similar haemoglobin concentrations (MD 0.43 g/L, 95% CI -1.44 to 2.31; 10 studies, 2127 participants; low-quality evidence) but lower ferritin concentrations on average (MD -6.07 μg/L, 95% CI -10.66 to -1.48; 4 studies, 988 participants; low-quality evidence) compared to daily supplementation. Compared to daily regimens, intermittent regimens may also reduce the risk of having iron deficiency (RR 4.30, 95% CI 0.56 to 33.20; 1 study, 198 participants; very low-quality evidence). Women receiving iron supplements intermittently were less likely to have any adverse side effects than those receiving iron supplements daily (RR 0.41, 95% CI 0.21 to 0.82; 6 studies, 1166 participants; moderate-quality evidence). No studies reported on the effect of intermittent regimens versus daily regimens on iron deficiency anaemia and all-cause morbidity.Information on disease outcomes, adherence, economic productivity, and work performance was scarce, and evidence about the effects of intermittent supplementation on these outcomes unclear.Overall, whether the supplements were given once or twice weekly, for less or more than three months, contained less or more than 60 mg of elemental iron per week, or given to populations with different degrees of anaemia at baseline did not seem to affect the findings. Furthermore, the response did not differ in areas where malaria was frequent, although very few trials were conducted in these settings.

AUTHORS' CONCLUSIONS

Intermittent iron supplementation may reduce anaemia and may improve iron stores among menstruating women in populations with different anaemia and malaria backgrounds. In comparison with daily supplementation, the provision of iron supplements intermittently is probably as effective in preventing or controlling anaemia. More information is needed on morbidity (including malaria outcomes), side effects, work performance, economic productivity, depression, and adherence to the intervention. The quality of this evidence base ranged from very low to moderate quality, suggesting that we are uncertain about these effects.

Determinants of dietary practices during pregnancy: A longitudinal qualitative study in Niger

Undernutrition is associated with maternal morbidity and poor pregnancy outcomes. This qualitative study seeks to understand the multilevel factors influencing maternal dietary practices in Niger, including the impact of pregnancy illnesses on diet. Criterion-based, purposive sampling was used to select pregnant women and household members from 24 villages in a rural district of the Maradi Region in south-central Niger. Semistructured interviews (n = 153) and focus group discussions (n = 38) explored 4 primary themes: (a) perceptions of ideal diet during pregnancy, (b) barriers to consuming the ideal diet, (c) coping strategies including dietary responses related to pregnancy illnesses, and (d) changes in perceptions from early to late pregnancy. Longitudinal data collection allowed for repeated interviews of pregnant women to document changes in dietary practices throughout pregnancy. Transcripts were coded using an inductive approach informed by grounded theory methodology. Participants categorized foods into 4 primary dietary taxonomies when discussing ideal maternal diets but cited constraints related to accessibility and availability impeding routine consumption of these foods. Perceptions of "modern," urban foods as healthy, coupled with key structural barriers such as food costs, were identified. Maternal morbidity influenced food consumption, as women reported reducing food intake early in pregnancy in response to illness episodes. Although awareness of optimal foods for supporting healthy pregnancies was moderately high, some misconceptions were observed and multilevel barriers to food security restricted opportunities for consuming these foods. Nutrition-specific and nutrition-sensitive interventions could improve access and availability of acceptable foods for supporting increased dietary intake during pregnancy.

Monitoring and surveillance for multiple micronutrient supplements in pregnancy

The World Health Organization (WHO) recommends iron–folic acid (IFA) supplementation during pregnancy to improve maternal and infant health outcomes. Multiple micronutrient (MMN) supplementation in pregnancy has been implemented in select countries and emerging evidence suggests that MMN supplementation in pregnancy may provide additional benefits compared to IFA alone. In 2015, WHO, the United Nations Children's Fund (UNICEF), and the Micronutrient Initiative held a “Technical Consultation on MMN supplements in pregnancy: implementation considerations for successful incorporation into existing programmemes,” which included a call for indicators needed for monitoring, evaluation, and surveillance of MMN supplementation programmes. Currently, global surveillance and monitoring data show that overall IFA supplementation programmes suffer from low coverage and intake adherence, despite inclusion in national policies. Common barriers that limit the effectiveness of IFA—which also apply to MMN programmes—include weak supply chains, low access to antenatal care services, low‐quality behaviour change interventions to support and motivate women, and weak or non‐existent monitoring systems used for programme improvement. The causes of these barriers in a given country need careful review to resolve them. As countries heighten their focus on supplementation during pregnancy, or if they decide to initiate or transition into MMN supplementation, a priority is to identify key monitoring indicators to address these issues and support effective programmes. National and global monitoring and surveillance data on IFA supplementation during pregnancy are primarily derived from cross‐sectional surveys and, on a more routine basis, through health and logistics management information systems. Indicators for IFA supplementation exist; however, the new indicators for MMN supplementation need to be incorporated. We reviewed practice‐based evidence, guided by the WHO/Centers for Disease Control and Prevention logic model for vitamin and mineral interventions in public health programmes, and used existing manuals, published literature, country reports, and the opinion of experts, to identify monitoring, evaluation, and surveillance indicators for MMN supplementation programmes. We also considered cross‐cutting indicators that could be used across programme settings, as well as those specific to common delivery models, such as antenatal care services. We then described mechanisms for collecting these data, including integration within existing government monitoring systems, as well as other existing or proposed systems. Monitoring data needs at all stages of the programme lifecycle were considered, as well as the feasibility and cost of data collection. We also propose revisions to global‐, national‐, and subnational‐surveillance indicators based on these reviews.

Multiple micronutrient powders for home (point-of-use) fortification of foods in pregnant women

BACKGROUND

It is estimated that 32 million pregnant women suffer from anaemia worldwide. Due to increased metabolic demands, pregnant women are particularly vulnerable to anaemia and vitamin and mineral deficiencies, leading to adverse health effects in both the mother and her baby. Despite the demonstrated benefits of prenatal supplementation with iron and folic acid or multiple micronutrients, poor adherence to routine supplementation has limited the effectiveness of this intervention in many settings. Micronutrient powders for point-of-use fortification are packed, single-dose sachets containing vitamins and minerals that can be added onto prepared food to improve its nutrient profile. The use of multiple micronutrient powders for point-of-use fortification of foods in pregnant women could be an alternative intervention to prenatal micronutrient supplementation.

OBJECTIVES

To assess the effects of prenatal home (point-of-use) fortification of foods with multiple micronutrient powders on maternal and newborn health.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015) and the International Clinical Trials Registry Platform (ICTRP) (31 January 2015). We also contacted relevant agencies to identify ongoing and unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (both individual and cluster randomisation) and quasi-randomised trials, irrespective of language or publication status.The intervention was micronutrient powders for point-of-use fortification of foods, containing at least three micronutrients with one of them being iron, provided to pregnant women of any gestational age and parity. Five comparison groups were considered: no intervention/placebo, iron and folic acid supplements, iron-only supplements, folic-acid only supplements, and multiple micronutrients in supplements.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies, extracted and checked data accuracy, and assessed the risk of bias of included studies.

MAIN RESULTS

Our search identified 12 reports (relating to six studies). We included two cluster-randomised controlled trials (involving 1172 women) - these trials were considered to be at a moderate to high risk of bias due to methodological limitations. One trial is ongoing, and three studies were excluded. Micronutrient powders for point-of-use fortification of foods versus iron and folic acid supplementsOne trial (involving 478 pregnant women attending 42 antenatal care centres) compared micronutrient powders containing iron, folic acid, vitamin C and zinc with iron and folic acid tablets provided daily from 14 to 22 weeks to 32 weeks' gestation. The trial did not report on any of this review's primary outcomes: maternal anaemia at or near term, maternal iron deficiency, maternal mortality, adverse effects, low birthweight, preterm births. Nor did the trial report on the majority of this review's secondary outcomes, with the exception of maternal adherence. Adherence to micronutrient powders was lower than adherence to iron and folic acid supplements (risk ratio (RR) 0.76, 95% confidence interval (CI) 0.66 to 0.87, one study, n = 405). Micronutrient powders for point-of-use fortification of foods versus same multiple micronutrients in supplementsOne study (involving 694 pregnant women from 18 communities), compared micronutrient powders containing iron, folic acid, vitamin C, zinc, iodine, vitamin E and vitamin B12 with tablets containing the same seven micronutrients. There was no difference in maternal anaemia at 37 weeks of gestation (RR 0.92, 95% CI 0.53 to 1.59, one study, n = 470, very low quality evidence). The trial did not report on any of this review's other primary outcomes in relation to maternal iron deficiency, maternal mortality, adverse effects, low birthweight, or preterm birth. In terms of this review's secondary outcomes, the included trial did not report on the majority of this review's prespecified secondary outcomes with one exception - there was no clear difference in maternal haemoglobin Hb or near term (mean difference (MD) 1.0 g/L, 95% CI -1.77 to 3.77, one study, n = 470).

AUTHORS' CONCLUSIONS

Limited evidence suggests that micronutrient powders for point-of-use fortification of foods have no clear difference as multiple micronutrient supplements on maternal anaemia (very low quality evidence) and Hb at or near term. There is limited evidence to suggest that women were more likely to adhere to taking tablets than using micronutrient powders.The overall quality of evidence was judged very low (due to methodological limitations), and no evidence was available for the majority of primary and secondary outcomes. Therefore, more evidence is needed to assess the potential benefits or harms of the use of micronutrient powders in pregnant women on maternal and infant health outcomes. Future trials should also assess adherence to micronutrient powders and be adequately powered to evaluate the effects on birth outcomes and morbidity.

Impact of prenatal multiple micronutrients on survival and growth during infancy: a randomized controlled trial

BACKGROUND

Although prenatal multiple micronutrients can improve fetal growth, their benefit on postnatal health remains uncertain.

OBJECTIVE

We assessed the effect of the UNICEF/WHO/United Nations University multiple micronutrient supplement for pregnant and lactating women (UNIMMAP) compared with the usual iron and folic acid supplement (IFA) on survival, growth, and morbidity during infancy.

DESIGN

In a double-blind, randomized trial, we followed 1294 singleton newborns whose mothers had prenatally received either the UNIMMAP or IFA. We assessed monthly anthropometric measures and health variables up to age 12 mo. Children were assessed again at a mean age of 30 mo. Mixed-effects models accounted for repeated measurements.

RESULTS

The UNIMMAP resulted in a 27% (HR: 0.73; 95% CI: 0.60, 0.87; P = 0.002) reduction in the rate of stunting in 15,261 infant-months with a higher length-for-age z score of 0.13 (95% CI: 0.02, 0.24; P = 0.02) over the whole observation period. However, by age 30 mo, this difference was not observed. An effect of the UNIMMAP on weight-for-length (P-interaction = 0.004) and head circumference-for-age (P-interaction = 0.03) became apparent by the end of the first year of life. By the age of 30 mo, children from the UNIMMAP group had a higher weight-for-height z score of 0.20 (95% CI: 0.06, 0.34; P = 0.004). No difference in mortality or morbidity was identified in groups, except a 14% reduction in reported episodes of fever (95% CI: 1%, 28%; P = 0.04).

CONCLUSIONS

Improved linear fetal growth with continuation into early life and enhanced postnatal growth were 2 mechanisms that mediated the effect of the prenatal UNIMMAP on infant nutritional status. Additional follow-up to assess long-term effects is warranted.

Intermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women

BACKGROUND

Daily iron supplementation has been traditionally a standard practice for preventing and treating anaemia but its long term use has been limited as it has been associated with adverse side effects such as nausea, constipation and teeth staining. Intermittent iron supplementation has been suggested as an effective and safer alternative to daily iron supplementation for preventing and reducing anaemia at population level, especially in areas where this condition is highly prevalent.

OBJECTIVES

To assess the effects of intermittent oral iron supplementation, alone or in combination with other nutrients, on anaemia and its associated impairments in menstruating women, compared with no intervention, a placebo or daily supplementation.

SEARCH METHODS

We searched the following databases in May 2011: CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE (1948 to May Week 3, 2011), EMBASE (1980 to 2011 Week 20), CINAHL (1937 to current), POPLINE (all available years), Science Citation Index (1970 to 27 May 2011), BIOSIS Previews (1969 to current), and CPCI-S (1990 to 27 May 2011). On 7 July 2011 we searched all available years in the following databases: SCIELO, LILACS, IBECS and IMBIOMED, the Networked Digital Library of Theses and Dissertations, metaRegister and the WHO International Clinical Trials Registry Platform (ICTRP). We also contacted relevant organisations (on 11 October 2011) to identify ongoing and unpublished studies.

SELECTION CRITERIA

Randomised and quasi-randomised trials with either individual or cluster randomisation. Participants were menstruating women, that is women beyond menarche and prior to menopause who were not pregnant or lactating and did not have a known condition that impeded the presence of menstrual periods. The intervention was the use of iron supplements intermittently (one, two or three times a week on non-consecutive days) compared with no intervention, a placebo, or the use of same supplements on a daily basis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies against the inclusion criteria, extracted data from included studies, checked data entry for accuracy and assessed the risk of bias of the included studies.

MAIN RESULTS

We included 21 trials involving 10,258 women. Although the quality across trials was variable, the results consistently show that in comparison with no intervention or a placebo, intermittent iron supplementation (alone or with any other vitamins and minerals) reduces the risk of having anaemia (RR 0.73; 95% CI 0.56 to 0.95, 10 trials) and improves the concentration of haemoglobin (MD 4.58 g/L; 95% CI 2.56 to 6.59, 13 trials) and ferritin (MD 8.32 μg/L; 95% CI 4.97 to 11.66, six trials). However, in comparison with daily supplementation, women receiving supplements intermittently presented anaemia more frequently (RR 1.26; 95% CI 1.04 to 1.51, six trials), despite achieving similar haemoglobin concentrations on average (MD -0.15 g/L; 95% CI -2.20 to 1.91, eight trials).Information on disease outcomes, adherence, side effects, economic productivity and work performance is scarce and the evidence about the effects of intermittent supplementation on them is unclear.Overall, whether the supplements were given once or twice weekly, for less or more than three months, contained less or more than 60 mg of elemental iron per week, or to populations with different degrees of anaemia at baseline did not seem to affect the findings. Furthermore, the response did not differ in areas where malaria is frequent, although very few trials were conducted in these settings.

AUTHORS' CONCLUSIONS

Intermittent iron supplementation in menstruating women is a feasible intervention in settings where daily supplementation is likely to be unsuccessful or not possible. In comparison with daily supplementation, the provision of iron supplements intermittently is less effective in preventing or controlling anaemia. More information is needed on morbidity (including malaria outcomes), side effects, work performance, economic productivity, depression and adherence to the intervention.

Vitamins and minerals for women: recent programs and intervention trials

Women's nutrition has received little attention in nutrition programming, even though clinical trials and intervention trials have suggested that dietary improvement or supplementation with several nutrients may improve their health, especially in low-income settings, the main focus of this paper. Most attention so far has focused on how improvements in maternal nutrition can improve health outcomes for infants and young children. Adequate vitamin D and calcium nutrition throughout life may reduce the risk of osteoporosis, and calcium supplementation during pregnancy may reduce preeclampsia and low birth weight. To reduce neural tube defects, additional folic acid and possibly vitamin B(12) need to be provided to non-deficient women before they know they are pregnant. This is best achieved by fortifying a staple food. It is unclear whether maternal vitamin A supplementation will lead to improved health outcomes for mother or child. Iron, iodine and zinc supplementation are widely needed for deficient women. Multimicronutrient supplementation (MMS) in place of the more common iron-folate supplements given in pregnancy in low-income countries may slightly increase birth weight, but its impact on neonatal mortality and other outcomes is unclear. More sustainable alternative approaches deserve greater research attention.