Nutritional factors and vertical transmission of HIV-1. Epidemiology and potential mechanisms

Breast Milk-Derived Retinol Is a Potential Surrogate for Serum in the 13C-Retinol Isotope Dilution Test in Zambian Lactating Women with Vitamin A Deficient and Adequate Status

BACKGROUND

Vitamin A (VA) deficiency (VAD) affects ∼19 million pregnant women worldwide. The extent of VAD in Zambian women of reproductive age is unknown owing to lack of survey inclusion or the use of static serum retinol concentrations, a low-sensitivity biomarker.

OBJECTIVES

This cross-sectional study employed isotopic techniques to determine VA status with serum and milk among women aged 18-49 y (n = 197) either lactating with infants aged 0-24 mo or nonlactating with or without infants.

METHODS

Assistants were trained and piloted data collection. Demographic data, anthropometry, and relevant histories were obtained including malaria and anemia. For retinol isotope dilution (RID), baseline fasting blood and casual breast milk samples were collected before administration of 2.0 μmol 13C2-retinyl acetate and 24-h dietary recalls. On day 14, blood (n = 144) and milk (n = 66) were collected. Prevalence of total liver VA reserves (TLR) ≤0.10 μmol/g was defined as VAD with comparison to the DRI assumption of 0.07 μmol/g as minimally acceptable for North Americans.

RESULTS

When a 20% adjustment for dose lost to milk was made in the RID equation for lactation, mean total body VA stores (TBS) for lactating women were 25% lower than for nonlactating women (P < 0.01), which was not the case without adjustment (P = 0.3). Mean ± SD TLR for all women were 0.15 ± 0.11 μmol/g liver. Using retinol purified from breast milk instead of serum for RID analysis yielded similar TBS and TLR, which were highly correlated between methods (P < 0.0001). Serum retinol ≤0.70 μmol/L had 0% sensitivity using either VAD liver cutoff and milk retinol ≤1.0 μmol/L had 42% sensitivity for VAD at 0.10 μmol/g.

CONCLUSIONS

Determining accurate VA status among women of reproductive age, especially lactating women, forms a basis for extrapolation to the general population and informing policy development and program implementation.

Vitamin A supplements for reducing mother-to-child HIV transmission

BACKGROUND

Strategies to reduce the risk of mother-to-child transmission of the human immunodeficiency virus (HIV) include lifelong antiretroviral therapy (ART) for HIV-positive women, exclusive breastfeeding from birth for six weeks plus nevirapine or replacement feeding plus nevirapine from birth for four to six weeks, elective Caesarean section delivery, and avoiding giving children chewed food. In some settings, these interventions may not be practical, feasible, or affordable. Simple, inexpensive, and effective interventions (that could potentially be implemented even in the absence of prenatal HIV testing programmes) would be valuable. Vitamin A, which plays a role in immune function, is one low-cost intervention that has been suggested in such settings.

OBJECTIVES

To summarize the effects of giving vitamin A supplements to HIV-positive women during pregnancy and after delivery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to 25 August 2017, and checked the reference lists of relevant articles for eligible studies.

SELECTION CRITERIA

We included randomized controlled trials conducted in any setting that compared vitamin A supplements to placebo or no intervention among HIV-positive women during pregnancy or after delivery, or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility and extracted data. We expressed study results as risk ratios (RR) or mean differences (MD) as appropriate, with their 95% confidence intervals (CI), and conducted random-effects meta-analyses. This is an update of a review last published in 2011.

MAIN RESULTS

Five trials met the inclusion criteria. These were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005 and none of the participants received ART. Women allocated to intervention arms received vitamin A supplements at a variety of doses (daily during pregnancy; a single dose immediately after delivery, or daily doses during pregnancy plus a single dose after delivery). Women allocated to comparison arms received identical placebo (6601 women, 4 trials) or no intervention (697 women, 1 trial). Four trials (with 6995 women) had low risk of bias and one trial (with 303 women) had high risk of attrition bias.The trials show that giving vitamin A supplements to HIV-positive women during pregnancy, the immediate postpartum period, or both, probably has little or no effect on mother-to-child transmission of HIV (RR 1.07, 95% CI 0.91 to 1.26; 4428 women, 5 trials, moderate certainty evidence) and may have little or no effect on child death by two years of age (RR 1.06, 95% CI 0.92 to 1.22; 3883 women, 3 trials, low certainty evidence). However, giving vitamin A supplements during pregnancy may increase the mean birthweight (MD 34.12 g, 95% CI -12.79 to 81.02; 2181 women, 3 trials, low certainty evidence) and probably reduces the incidence of low birthweight (RR 0.78, 95% CI 0.63 to 0.97; 1819 women, 3 trials, moderate certainty evidence); but we do not know whether vitamin A supplements affect the risk of preterm delivery (1577 women, 2 trials), stillbirth (2335 women, 3 trials), or maternal death (1267 women, 2 trials).

AUTHORS' CONCLUSIONS

Antepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs. The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.

Vitamin A deficiency during pregnancy of HIV infected and non-infected women in tropical settings of Northwest Ethiopia

BACKGROUND

Vitamin A deficiency (VAD) is known to be a major public health problem among women of reproductive age in South East Asia and Africa. In Ethiopia, there are no studies conducted on serum vitamin A status of HIV-infected pregnant women. Therefore, the present study was aimed at determining the level of serum vitamin A and VAD among pregnant women with and without HIV infection in tropical settings of Northwest Ethiopia.

METHODS

In this cross-sectional study, blood samples were collected from 423 pregnant women and from 55 healthy volunteers who visited the University of Gondar Hospital. Serum concentration of vitamin A was measured by high performance liquid chromatography.

RESULTS

After controlling for total serum protein, albumin and demographic variables, the mean ± SD serum vitamin A in HIV seropositive pregnant women (0.96 ± 0.42 μmol/L) was significantly lower than that in pregnant women without HIV infection (1.10 ± 0.45 μmol/L, P < 0.05). Likewise, the level of serum vitamin A in HIV seropositive non-pregnant women (0.74 ± 0.39) was significantly lower than that in HIV negative non-pregnant women (1.18 ± 0.59 μmol/L, P < 0.004). VAD (serum retinol < 0.7 μmol/L) was observed in 18.4% and 17.7% of HIV infected and uninfected pregnant women, respectively. Forty six percent of non-pregnant women with HIV infection had VAD while only 28% controls were deficient for vitamin A (P = 0.002).

CONCLUSION

The present study shows that VAD is a major public health problem among pregnant women in the tropical settings of Northwest Ethiopia. Considering the possible implications of VAD during pregnancy, we recommend multivitamin (which has a lower level of vitamin A) supplementation in the care and management of pregnant women with or without HIV infection.

Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection

BACKGROUND

Observational studies of pregnant women in sub-Saharan Africa have shown that low serum vitamin A levels are associated with an increased risk of mother-to-child transmission (MTCT) of HIV. Vitamin A is cheap and easily provided through existing health services in low-income settings. It is thus important to determine the effect of routine supplementation of HIV positive pregnant or breastfeeding women with this vitamin on the risk of MTCT of HIV, which currently results in more than 1000 new HIV infections each day world-wide.

OBJECTIVES

We aimed to assess the effect of antenatal and or postpartum vitamin A supplementation on the risk of MTCT of HIV as well as infant and maternal mortality and morbidity.

SEARCH STRATEGY

In June 2010 we searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, AIDS Education Global Information System, and WHO International Clinical Trials Registry Platform; and checked reference lists of identified articles for any studies published after the earlier version of this review was updated in 2008.

SELECTION CRITERIA

We selected randomised controlled trials conducted in any setting that compared vitamin A supplementation with placebo in known HIV-infected pregnant or breastfeeding women.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed trial eligibility and quality and extracted data. We calculated relative risks (RR) or mean differences (MD), with their 95% confidence intervals (CI) for each study. We conducted meta-analysis using a fixed-effects method (when there was no significant heterogeneity between study results, i.e. P>0.1) or the random-effects method (when there was significant heterogeneity), and report the Higgins' statistic for all pooled effect measures.

MAIN RESULTS

Five randomised controlled trials which enrolled 7,528 HIV-infected women (either during pregnancy or the immediate postpartum period) met our inclusion criteria. These trials were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005. We combined the results of these trials and found no evidence that vitamin A supplementation has an effect on the risk of MTCT of HIV (4 trials, 6517 women: RR 1.04, 95% CI 0.87 to 1.24; I(2)=68%). However, antenatal vitamin A supplementation significantly improved birth weight (3 trials, 1809 women: MD 89.78, 95%CI 84.73 to 94.83; I(2)=33.0%), but there was no evidence of an effect on preterm births (3 trials, 2110 women: RR 0.88, 95%CI 0.65 to 1.19; I(2)=58.1%), stillbirths (4 trials, 2855 women: RR 0.99, 95%CI 0.68 to 1.43; I(2)=0%), deaths by 24 months (2 trials, 1635 women: RR 1.03, 95%CI 0.88 to 1.20; I(2)=0%), postpartum CD4 levels (1 trial, 727 women: MD -4.00, 95% CI -51.06 to 43.06), and maternal death ( 1 trial, 728 women: RR 0.49, 95%CI 0.04 to 5.37).

AUTHORS' CONCLUSIONS

Current best evidence shows that antenatal or postpartum vitamin A supplementation probably has little or no effect on mother-to-child transmission of HIV. According to the GRADE classification, the quality of this evidence is moderate; implying that the true effect of vitamin A supplementation on the risk of mother-to-child transmission of HIV is likely to be close to the findings of this review, but that there is also a possibility that it is substantially different.

Role of selenium in HIV infection

HIV infection is a global disease that disproportionately burdens populations with nutritional vulnerabilities. Laboratory experiments have shown that selenium has an inhibitory effect on HIV in vitro through antioxidant effects of glutathione peroxidase and other selenoproteins. Numerous studies have reported low selenium status in HIV-infected individuals, and serum selenium concentration declines with disease progression. Some cohort studies have shown an association between selenium deficiency and progression to AIDS or mortality. In several randomized controlled trials, selenium supplementation has reduced hospitalizations and diarrheal morbidity, and improved CD4(+) cell counts, but the evidence remains mixed. Additional trials are recommended to study the effect of selenium supplementation on opportunistic infections, and other HIV disease-related comorbidities in the context of highly active antiretroviral therapy in both developing and developed countries.

Micronutrients and HIV infection

The immune system requires several essential micronutrients to maintain an effective immune response. HIV infection destroys the immune system and promotes nutritional deficiencies, which further impair immunity. This article reviews the role of several micronutrients (vitamins A, C, E and D, the B vitamins, and minerals, selenium, iron and zinc) that are relevant for maintaining immune function. In addition, the deficiencies of these micronutrients have been associated with faster progression of HIV-1 disease. This review examines the evidence from observational studies of an association between micronutrient status and HIV disease, as well as the effectiveness of micronutrient supplementation on HIV-disease progression, pregnancy outcomes and nutritional status, among others, utilizing randomized clinical trials. Each micronutrient is introduced with a summary of its functions in human physiology, followed by the presentation of studies conducted in HIV-infected patients in relation to this specific micronutrient. Overall findings and recommendations are then summarized.

Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection

BACKGROUND

Mother-to-child transmission (MTCT) of HIV is the dominant mode of acquisition of HIV infection for children, currently resulting in more than 2000 new paediatric HIV infections each day worldwide.

OBJECTIVES

To assess the effects of antenatal and intrapartum vitamin A supplementation on the risk of MTCT of HIV infection and infant and maternal mortality and morbidity, and the tolerability of vitamin A supplementation.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, AIDSLINE, LILACS, AIDSTRIALS, and AIDSDRUGS, using standardised methodological filters for identifying trials. We also searched reference lists of identified articles, relevant editorials, expert opinions and letters to journal editors, and abstracts or proceedings of relevant conferences; and contacted subject experts, agencies, organisations, academic centres, and pharmaceutical companies. There were no language restrictions.

SELECTION CRITERIA

Randomised trials comparing vitamin A supplementation with no vitamin A supplementation in known HIV infected pregnant women. Trials had to include an estimate of the effect of vitamin A supplementation on MTCT of HIV and or any other adverse pregnancy outcome to be included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and quality and extracted data. Effect measures (odds ratio [OR] for binary variables and weighted mean difference [WMD] for continuous variables) with their 95% confidence intervals (CI) were estimated for each study and combined using the fixed effect (Mantel-Haenszel) method, by intention to treat. Heterogeneity between studies was examined by graphical inspection of results followed by a chi-square test of homogeneity.

MAIN RESULTS

Four trials, which enrolled 3,033 HIV-infected pregnant women, are included in this review. There was no evidence of an effect of vitamin A supplementation on MTCT of HIV infection (OR 1.14, 95% CI 0.93 to 1.38). There was evidence of heterogeneity between the three trials with information on MTCT of HIV (I(2) =75.7%, P=0.02). While the trials conducted in South Africa (OR 0.98, 95% CI 0.67 to 1.42 at three months) and Malawi (OR 0.78, 95% CI 0.53 to 1.15 at 24 months) did not find evidence that the effect of Vitamin A supplementation was different from that of placebo, the trial in Tanzania did find evidence that vitamin A supplementation increased the risk of MTCT of HIV (OR 1.53, 95% CI 1.15 to 2.04 at 24 months). Vitamin A supplementation significantly improved birth weight (WMD 89.78, 95% CI 84.73 to 94.83), but there was no evidence of an effect of vitamin A supplementation on stillbirths (OR 0.99, 95% CI 0.67 to 1.46), preterm births (OR 0.89, 95% CI 0.71 to 1.11), death by 24 months among live births (OR 1.11, 95% CI 0.88 to 1.40), postpartum CD4 levels (WMD -4.00, 95% CI -51.06 to 43.06), and maternal death (OR 0.49, 95%CI 0.04 to 5.40).

IMPLICATIONS FOR PRACTICE

Currently available evidence do not support the use of vitamin A supplementation of HIV-infected pregnant women to reduce MTCT of HIV, though there is an indication that vitamin A supplementation improves birth weight.

IMPLICATIONS FOR RESEARCH

The awaited publication of data from a large trial involving 4,495 HIV infected pregnant women in Harare (Zimbabwe Vitamin A for Mothers and Babies Project), will further clarify the effect of vitamin A supplementation on MTCT of HIV. The current review will be updated as soon as the trial is published.

Vitamin A, Mastitis, and Mother-to-Child Transmission of HIV-1 through Breast-feeding: Current Information and Gaps in Knowledge

Mastitis has been implicated as a risk factor for mother-to-child transmission (MTCT) of HIV-1 through breast-feeding. Maternal vitamin A deficiency is also associated with increased MTCT, as well as with episodes of mastitis in lactating animals. This review describes the complex interrelationship between vitamin A, mastitis, and MTCT of HIV-1 via mothers' milk. Current gaps in knowledge, as well as recommendations for future research efforts, are also discussed.

Rethinking food aid to fight AIDS

While the realization that AIDS is far more than a health problem has dawned only recently, many development organizations have yet to undertake thorough analyses of what this means for what they do, and how they do it. Even fewer have actually changed their policies and procedures to adjust to these new realities. We know that food and nutrition are fundamentally intertwined with HIV transmission and the impacts of AIDS. Food and nutrition security is fundamentally relevant to all four of the conventional pillars of HIV/AIDS response-prevention, care, treatment, and mitigation-and food aid can be an important weapon in the arsenal. This paper, based on a detailed review of the relevant literature and the findings of a mission to eastern and southern Africa, highlights the implications of the HIV/AIDS pandemic for food aid strategy and programming. By viewing food aid programs through an "HIV/AIDS lens" and in the context of a livelihoods approach, the authors argue that organizations can effectively design interventions that reduce both susceptibility to HIV and vulnerability to AIDS impacts. Though there is little empirical evidence regarding the effectiveness of food aid in responding to HIV/AIDS, the authors argue that this should not constrain action. Using past experience as a guide, organizations can learn by doing, documenting, and continually reassessing their programs using the evolving lens, so as to ensure maximal relevance and impact.

Transmission of HIV-1 through breastfeeding among women in Dar es Salaam, Tanzania

BACKGROUND

Transmission of HIV-1 through breastfeeding is a major problem, although its timing is not well characterized.

METHODS

The authors examined the timing and correlates of HIV-1 transmission through breastfeeding among 1078 HIV-infected pregnant women from Dar es Salaam, Tanzania enrolled in a trial to examine the effect of vitamin A and other vitamin supplements on mother-to-child transmission of HIV-1 and other health outcomes. Cumulative incidence was measured among children of women not randomized to vitamin A (n = 312), given the higher risk of infection observed among those in the vitamin A arm. For analyses of correlates, data from all children not infected by age 6 weeks were used (p = 659).

RESULTS

Mean duration of breastfeeding was 20.3 months (SD = 4.4 months; median = 20.5 months). Thirty-seven infections were observed during 4372 child-months of follow-up evaluation, or 10.2 cases per 100 child-years. Infection risk by age 4 months was 3.8% (95% confidence interval [CI], 1.6%-6.1%) and increased to 17.9% (95% CI, 11.2%-24.5%) by age 24 months. In a multivariate proportional hazards model, high maternal viral load (p =.0001), low CD4 cell count (p =.004), and high maternal erythrocyte sedimentation rate (ESR; p=.004) were significant predictors of transmission of HIV-1 through breastfeeding. Mothers who had breast lesions during pregnancy were 2.00 times more likely to transmit the virus during breastfeeding than mothers without these lesions (95% CI, 1.29-3.08; p=.002).

CONCLUSIONS

The rate of breastfeeding transmission of HIV-1 is high, and early weaning is likely to be associated with reduced transmission. Antiretroviral drugs given to HIV-infected mothers are likely to reduce the risk of breastfeeding transmission. In their absence, interventions that enhance immune reconstitution, such as micronutrient supplements, may be beneficial against transmission. Methods to prevent and treat nipple cracks and mastitis may also be important.

Correlates of plasma HIV-1 RNA viral load among HIV-1-seropositive women in Dar es Salaam, Tanzania

This study was conducted to determine the predictors of plasma HIV-1 RNA viral load in HIV-1-positive pregnant women (N = 151) participating in a clinical trial in Tanzania. Viral load was measured at randomization, delivery, and approximately 7 months after delivery. The median viral load was 20,400 copies/mL at baseline, 20,216 copies/mL at delivery, and 19,100 copies/mL 7 months after delivery. The absolute CD4+ lymphocyte count had a strong negative correlation with HIV-1 RNA viral load at baseline (r = -.38), time of delivery (r = -.36), and 7 months after delivery (r = -.53). The association between CD4+ lymphocyte count and HIV-1 RNA viral load was modified by the per capita daily food expenditure in the household, although the difference in viral load became small as the food expenditure in the household increased and was marginally significant at the 75th percentile of the per capita food expenditure. The presence of malaria parasites at baseline was associated with an approximate 116% higher viral load at the three evaluation points (p =.007). Although the long-term effects of malaria on viral load are unknown, prevention of malaria among people living with HIV-1 should be given the highest priority.

Micronutrients and vertical transmission of HIV-1

ABSTRACT Vertical transmission of HIV from mother to infant can occur during pregnancy, at the time of delivery, or post-natally through breast-feeding and is a major factor in the continuing spread of HIV infection. Inadequate nutritional status may increase the risk of vertical HIV transmission by influencing mater-nal and child factors for transmission. The potential effects on these factors include impaired systemic immune function in pregnant women, fetuses, and children; an increased rate of clinical, immunologic, and virologic disease progression; impaired epithelial integrity of the placenta and genital tract; increased viral shedding in breast milk from inflammation of breast tissue; increased risk of low birth weight and preterm birth; and impaired gastrointestinal immune function and integrity in fetuses and children. Micronutrient deficiencies are prevalent in many HIV-infected populations, and numerous studies have reported that these deficiencies impair immune responses, weaken epithelial integrity, and are associated with accelerated HIV disease progression. Although low serum vitamin A concentrations were shown to be associated with an increased risk of vertical HIV transmission in prospective cohort studies, randomized, placebo-controlled trials have reported that vitamin A and other vitamin supplements do not appear to have an effect on HIV transmission during pregnancy or the intrapartum period. However, the ability of prenatal and postpartum micronutrient supplements to reduce transmission during the breast-feeding period is still unknown.

Transmission of HIV-1 from mother to infant

In the developed world, antiretroviral therapy (ART) administered to the mother during pregnancy and intrapartum and to the infant in the neonatal period has resulted in a reduction of the overall risk of vertical transmission of HIV-1 to approximately 8%. In some settings, ART combined with cesarean section and a reduction in duration of ruptured membranes has resulted in a further lessening of risk to levels < or = 2 percent. A number of less expensive and greatly abbreviated ART regimens, useful for application in resource poor settings, also have resulted in reductions of mother-to-infant transmission of HIV-1 by 33 to 50% compared to baseline. A multitude of studies have shown these drugs to be safe for mothers, fetuses, and newborns. Breastfeeding seems to represent a risk factor that adds to the risk of vertical transmission, especially in infants who are fed a combination of breastmilk and other liquids and solids. Studies designed to assess the possible benefits of treating genital ulcer disease, chorioamnionitis, mastitis, and malnutrition in HIV-infected women, and of applying antiseptic washes to the cervix and vagina during labor, are in progress.

Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection

BACKGROUND

Mother-to-child transmission (MTCT) of HIV is the dominant mode of acquisition of HIV infection for children, currently resulting in about 1800 new paediatric HIV infections each day world-wide. This is one of several reviews assessing the available evidence for preventing HIV transmission from an HIV-infected woman to her child. The other reviews assess the effects of antiretroviral therapy, Caesarean section delivery, breast feeding, and vaginal lavage.

OBJECTIVES

To assess the effects of antenatal and intrapartum vitamin A supplementation, compared to an appropriate control group, on the risk of MTCT of HIV infection and infant and maternal mortality and morbidity, and the tolerability of vitamin A supplementation.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register, Cochrane Pregnancy and Childbirth Register, PubMed, EMBASE, AIDSLINE, LILACS, AIDSTRIALS, and AIDSDRUGS, using standardised methodological filters for identifying trials. We also searched reference lists of identified articles, relevant editorials, expert opinions and letters to journal editors, and abstracts or proceedings of relevant conferences; and contacted subject experts, agencies, organisations, academic centres, and pharmaceutical companies. There were no language restrictions.

SELECTION CRITERIA

Randomised trials comparing vitamin A supplementation with no vitamin A supplementation in known HIV infected pregnant women. Trials had to include an estimate of the effect of vitamin A supplementation on MTCT of HIV and/or any other pre-specified adverse pregnancy outcome to be included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality and extracted data. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for binary data and pooled using a fixed effect (Mantel-Haenszel) method. Heterogeneity between studies was examined by graphical inspection of results followed by a chi-square test of homogeneity.

MAIN RESULTS

We identified five eligible trials, only two of which included an estimated of the effect of vitamin A supplementation on at least one of the pre-specified outcomes. Based on the two trials, with a total of 1813 participants, there is no evidence that vitamin A supplementation has an effect on MTCT of HIV (OR 1.09, 95% confidence interval (CI) 0.81 to 1.45). There is no evidence of heterogeneity between the trials (p = 0.37), and no evidence of an effect of vitamin A supplementation in HIV-infected pregnant women on stillbirths (OR 1.07, 95% CI 0.63 to 1.80), very preterm births, i.e. born less than 34 weeks gestation (OR 0.86, 95% CI 0.57 to 1.31), all preterm births, i.e. born less than 37 weeks gestation (OR 0.88, 95% CI 0.68 to 1.13), low birth weight, i.e. weighing less than 2500g (OR 0.86, 95% CI 0.64 to 1.17), very low birthweight, i.e. weighing less than 2000g (OR 0.71, 95% CI 0.40 to 1.28), and postpartum CD4 levels (weighted mean difference -4.00, 95% CI -51.06 to 43.06). The effect of vitamin A on maternal mortality could not be assesssed, as there were only three maternal deaths.

IMPLICATIONS FOR PRACTICE

At the present time there is no conclusive evidence that the antenatal and intrapartum use of vitamin A supplementation to reduce MTCT of HIV and adverse pregnancy outcomes among HIV-infected pregnant women should be recommended.

IMPLICATIONS FOR RESEARCH

The current review will be updated as soon as data from ongoing studies become available. This review and the review in progress on vitamin A supplementation in pregnant women of seronegative/unknown HIV status (Kulier 2002) should be considered together in order to shed more light on the effect of vitamin A supplementation on non-HIV related adverse pregnancy outcomes.

Micronutrients and child health: studies in international nutrition and HIV infection

Increasing data link micronutrient deficiencies to excess childhood morbidity and mortality, and similar relationships have been noted in the study of nutrition and HIV infection. We review epidemiologic studies that have examined the relationship between micronutrient deficiencies and health outcomes in childhood and HIV infection, as well as clinical trials of micronutrient supplementation. Vitamin A supplementation among communities at risk of deficiency effectively reduces mortality and morbidity in children younger than age 5, and vitamin A may be especially effective in HIV-infected children. Vertical transmission of HIV has not to date been affected by maternal micronutrient supplementation. In children with poor dietary zinc intake and/or bioavailability, zinc supplementation reduces the incidence and severity of diarrheal diseases, as well as the occurrence of pneumonia. Vitamin A therapy has not been associated with improved growth, whereas some trials have shown that zinc supplementation is associated with greater increments in height. Further trials of micronutrient supplementation are warranted.