Night blindness of pregnancy in rural Nepal--nutritional and health risks

Newborn vitamin A supplementation reduced infant mortality in rural Bangladesh

OBJECTIVES

We assessed the effect of supplementing newborns with 50000 IU of vitamin A on all-cause infant mortality through 24 weeks of age.

PATIENTS AND METHODS

This was a community-based, double-masked, cluster-randomized, placebo-controlled trial conducted in 19 unions in rural northwest Bangladesh. The study was nested into and balanced across treatment arms of an ongoing placebo-controlled, weekly maternal vitamin A or beta-carotene supplementation trial. Study-defined sectors (N = 596) were evenly randomized for newborns of participating mothers to receive a single, oral supplement of vitamin A (50000 IU) or placebo as droplets of oil squeezed from a gelatinous capsule. Mothers provided informed consent for newborn participation at approximately 28 weeks' gestation. After birth, typically at home (where >90% of births occurred), infants were supplemented and their vital status was followed through 24 weeks of age. The main outcome measure was mortality through 24 weeks of age.

RESULTS

We obtained maternal consent to dose 17116 live-born infants (99.8% of all eligible) among whom 15937 (93.1%) were visited to be supplemented <30 days after birth and for whom vital status at 24 weeks of age was known. Dosed infants (n = 15902 [99.8%]) received their study supplement at a median age of 7 hours. Relative to control subjects, the risk of death in vitamin A-supplemented infants was 0.85, reflecting a 15% reduction in all-cause mortality. Protective relative risks were indistinguishable by infant gender, gestational age, birth weight, age at dosing, maternal age, parity, or across the 3 treatment arms of the maternal supplementation trial.

CONCLUSIONS

Newborn vitamin A dosing improved infant survival through the first 6 months of life in Bangladesh. These results corroborate previous findings from studies in Indonesia and India and provide additional evidence that vitamin A supplementation shortly after birth can reduce infant mortality in South Asia.

Extent of vitamin A deficiency among rural pregnant women in Bangladesh

OBJECTIVE

To investigate the prevalence of vitamin A deficiency (VAD) among pregnant women in rural Bangladesh, and examine the relationship between various factors and vitamin A status.

SETTING

Community Nutrition Promoter (CNP) centres in Kapasia sub-district of Gazipur district, Bangladesh.

DESIGN

A cross-sectional study.

SUBJECTS AND METHODS

Two hundred women, aged 18-39 years, in their second or third trimester of pregnancy were selected from seventeen CNP centres in four unions of Kapasia sub-district where they usually visit for antenatal care. Various socio-economic, personal and pregnancy-related information, dietary intake of vitamin A and mid-upper arm circumference (MUAC) data were collected. Serum retinol (vitamin A) concentration was determined.

RESULTS

More than half (51 %) of the pregnant women had low vitamin A status (serum retinol <1.05 micromol/l) with 18.5 % having VAD (serum retinol <0.70 micromol/l). Fifty-three per cent of the women's vitamin A intake was less than the recommended dietary allowance. By multiple regression analysis, MUAC, per-capita expenditure on food and wealth index were found to have significant independent positive relationship with serum retinol concentration, while gestational age of the pregnant women had a negative relationship. The overall F-ratio (10.3) was highly significant (P = 0.0001), the adjusted R2 was 0.18 (multiple R = 0.45).

CONCLUSION

VAD is highly prevalent among rural pregnant women in Bangladesh. Gestational age, nutritional status, per-capita expenditure on food and wealth index appear to be important in influencing the vitamin A status of these women. An appropriate intervention is warranted in order to improve the vitamin A status.

Maternal night blindness during pregnancy is associated with low birthweight, morbidity, and poor growth in South India

Maternal night blindness is common during pregnancy in many developing countries. Previous studies have demonstrated important consequences of maternal night blindness during pregnancy on the health of the mother and newborn infant. We compared birthweight, 6-mo infant mortality, morbidity, and growth among infants of women who did and did not report a history of night blindness from a community-based, randomized trial of newborn vitamin A supplementation in south India. Birthweight was measured within 72 h of delivery. Infants were followed until 6 mo of age for mortality and morbidity was assessed at household visits every 2 wk. Anthropometry was assessed at 6 mo of age. A total of 12,829 live-born infants were included, 680 of whom were infants of mothers with night blindness during the index pregnancy. Maternal night blindness was associated with an increased risk of low birthweight in a dose-dependent fashion based on birthweight cut-offs: <2500 g, adjusted relative risk (RR) = 1.13 (95% CI = 1.01, 1.26); <2000 g, adjusted RR = 1.70 (95% CI = 1.27, 2.26); <1500 g, adjusted RR = 3.38 (95% CI = 1.18, 6.33); with an increased risk of diarrhea (adjusted RR = 1.16, 95% CI = 1.03, 1.30), dysentery (adjusted RR = 1.25, 95% CI = 1.03, 1.53), acute respiratory illness (adjusted RR = 1.32, 95% CI = 1.21, 1.44), and poor growth at 6 mo; underweight (adjusted RR = 1.14, 95% CI = 1.02, 1.26), stunting (adjusted RR = 1.19, 95% CI = 1.05, 1.34). Maternal night blindness was not associated with 6-mo infant mortality or wasting at 6 mo. This study demonstrates that there are important consequences to the infant of maternal vitamin A deficiency during pregnancy.

Risk factors for pregnancy-related mortality: a prospective study in rural Nepal

OBJECTIVES

This study examined the risk factors of mortality related to pregnancy for the first year post partum in a cohort of 25,580 pregnancies.

STUDY DESIGN

Longitudinal cohort follow-up.

METHODS

Details of socio-economic status, mid-upper arm circumference (MUAC), diet, illness, work, substance use and previous pregnancy history were collected during early to mid-gestation, and these women were followed for 1 year post partum. All-cause mortality rates per 100,000 pregnancies were calculated for deaths during pregnancy or up to 42 days post partum (early period) and 43-364 days post partum (late period). Odds ratios (OR) of mortality were estimated using five groups of risk factors: biological; morbidity; dietary; lifestyle; and socio-economic. Significant factors within each group were included in a single risk model for each time period.

RESULTS

Early and late pregnancy-related mortality rates were 469 [95% confidence interval (CI) 385-553] and 254 (95% CI 192-316), respectively. Maternal age > or = 35 years was associated with a three- to four-fold increase in mortality, whereas increasing parity conferred increasing protection. In the final model, a larger MUAC and consumption of dark green leaves were associated with decreased risk of death in the early period (OR 0.76, 95% CI 0.67-0.87 and 0.64, 95% CI 0.41-0.99, respectively). A larger MUAC was also associated with a lower risk of death in the late period. Diarrhoea/dysentery and pre-eclampsia were associated with increased risk of death in the early period (OR 2.78, 95% CI 1.40-5.51 and 2.95, 95% CI 1.48-5.90, respectively). Factors weakly associated (P<0.1) with mortality in both periods included night blindness, strenuous work activity and cigarette smoking. No socio-economic factors were significant in the models.

CONCLUSIONS

Maternal age, parity, MUAC, diet and illness in early to mid-gestation were associated with risk of death during pregnancy and the first year post partum in rural Nepal.

Supplementation with iron and riboflavin enhances dark adaptation response to vitamin A-fortified rice in iron-deficient, pregnant, nightblind Nepali women

BACKGROUND

Nightblindness affects 16-52% of pregnant women in areas of Nepal and in some cases persists after vitamin A treatment. Iron and riboflavin affect vitamin A utilization and photoreceptor function, respectively, and pilot data in the study population showed a high prevalence of iron and riboflavin deficiencies.

OBJECTIVE

The objective was to assess the effect of supplemental iron and riboflavin on pupillary threshold (PT) and plasma retinol in nightblind, pregnant Nepali women given vitamin A-fortified rice.

DESIGN

Nightblind pregnant women were randomly assigned to receive, 6 d/wk under supervision for 6 wk, a vitamin A-fortified rice curry dish providing 850 microg retinal activity equivalents/d with either a 30-mg Fe and 6-mg riboflavin (FeR + VA) capsule or a placebo control (VA only) capsule. Hemoglobin, erythrocyte riboflavin, and plasma ferritin and retinol were measured before and after the intervention. Dark adaptation was assessed by PT score.

RESULTS

Women who were iron deficient at baseline (n=38) had significantly greater improvement in PT score with iron and riboflavin supplementation than without (P=0.05). Iron and riboflavin supplements significantly reduced the prevalences of riboflavin deficiency (from 60% to 6%; P<0.0001), iron deficiency anemia (from 35% to 15%; P<0.007), and abnormal PT (from 87% to 30%; P<0.05) from baseline. Mean increases in erythrocyte riboflavin (P<0.0001) and plasma ferritin (P=0.01) were greater in the FeR + VA group than in the VA only group.

CONCLUSIONS

Iron deficiency may limit the efficacy of vitamin A to normalize dark adaptation in pregnant Nepali women. Further studies are needed to assess the effect of simultaneous delivery of iron and vitamin A for the treatment of nightblindness.

Association of serum concentrations of retinol and carotenoids with overweight in children and adolescents

OBJECTIVE

A study was conducted to verify the association between serum concentrations of retinol and carotenoids with overweight in children and adolescents.

METHODS

In total 471 children (7-9.9 y of age) and adolescents (10-17 y of age), living in a poor region of the city of Rio de Janeiro, Brazil, were assessed. Serum concentrations of retinol and carotenoids were assessed by high-performance liquid chromatography, and cutoffs for inadequacy of retinol and carotenoids were <30 and <40 microg/dL, respectively. Overweight was defined by the sex- and age-specific body mass index cutoffs recommended by World Health Organization. The logistic regression model was used to test the association of overweight, gender, and age range with low serum concentrations of retinol and carotenoids.

RESULTS

Prevalences were 10% for low serum concentration of retinol, 55.8% for carotenoids, and 15.3% for overweight. Retinol inadequacy was significantly higher in adolescents (12.6%) than in children (6.8%). The average of carotenoids was significantly lower in overweight subjects (30.40 +/- 16.74 versus 43.06 +/- 25.26 microg/dL, P = 0.001). Overweight children and adolescents presented a greater chance of a decrease in serum concentrations of carotenoids (odds ratio 2.51, 95% confidence interval 1.43-4.39) when compared with non-overweight subjects.

CONCLUSION

An important prevalence of vitamin A deficiency was found. Overweight children, as much as adolescents, may have a greater chance of presenting low concentrations of carotenoids and, hence, a lower antioxidant defense.

A investigação da cegueira noturna no grupo materno-infantil: uma revisão histórica

Objetivou-se neste estudo apresentar uma revisão histórica sobre a cegueira noturna, um indicador funcional da deficiência de vitamina A. Realizou-se uma revisão da literatura científica publicada no período de 1929 a 2005, nas bases de dados Medline, Lilacs, SciELO e dos comitês nacionais e internacionais de saúde e de micronutrientes, utilizando-se os termos night blindness, xerophthalmia, pregnancy, post partum women, newborn, children, vitamin A deficiency, micronutrient, deficiência de vitamina A, micronutriente, cegueira noturna, gestação, xeroftalmia. O reconhecimento da importância do indicador funcional da deficiência de vitamina A foi consagrado em 1996 pela Organização Mundial de Saúde, a partir da recomendação de uma entrevista padronizada para investigação da cegueira noturna. O método se caracteriza por apresentar facilidades operacionais, ser de baixo custo, além de permitir a sua aplicação tanto para o monitoramento do estado nutricional de pessoas e comunidades, quanto para a avaliação da eficácia de programas de intervenção. Entre gestantes e nutrizes, estudos recentes sugerem a utilidade deste indicador no diagnóstico dos casos de deficiência de vitamina A ainda no estágio subclínico da deficiência, sendo grande a sua concordância com indicadores bioquímicos. Ao longo dos anos, verifica-se também o reconhecimento deste indicador como um instrumento importante para a predição do risco de morbimortalidade no grupo materno-infantil.

Lipid-soluble antioxidants status and some of its socio-economic determinants among pregnant Ethiopians at the third trimester

Objective

To determine the serum levels of three lipid-soluble antioxidants (retinol, β-carotene and α-tocopherol) in pregnant women attending an antenatal clinic (ANC) in Gondar, Ethiopia.

Design

A cross-sectional study involving laboratory determination of serum levels of retinol, α-tocopherol and β-carotene using high-performance liquid chromatography and questionnaire-based assessment of socio-economic status.

Setting

ANC of a university teaching hospital.

Subjects

Three hundred and twenty-two healthy pregnant women in their third trimester, who attended the ANC.

Results

Mean serum levels of retinol, α-tocopherol and β-carotene were found to be 1.23±0.5, 25.5±0.9 and 0.21±0.09 μmol l−1, respectively. The prevalence of vitamin A deficiency (<1.05 μmol l−1) among pregnant women was 38.5%. Women having low retinol (vitamin A) levels were highly likely to live in earth-floored and mud-walled houses, and less likely to own a house and to have a latrine.

Conclusion

The study shows that serum levels of lipid-soluble antioxidants were low among ANC attendees in northern Ethiopia. It also indicates that some socio-economic factors (such as poor housing standard) are associated with vitamin A deficiency.

Anaemia, iron status and vitamin A deficiency among adolescent refugees in Kenya and Nepal

Objective

To investigate the prevalence of anaemia (haemoglobin < 11.0 to 13.0 g dl−1depending on age and sex group), iron deficiency (transferrin receptor concentration > 8.3 μg ml−1) and vitamin A deficiency (serum retinol < 0.7 μmoll−1) in adolescent refugees.

Design

Cross-sectional surveys.

Setting

Kakuma refugee camp in Kenya and seven refugee camps in Nepal.

Subjects

Adolescent refugee residents in these camps.

Results

Anaemia was present in 46% (95% confidence interval (CI): 42–51) of adolescents in Kenya and in 24% (95% CI: 20–28) of adolescents in Nepal. The sensitivity of palmar pallor in detecting anaemia was 21%. In addition, 43% (95% CI: 36–50) and 53% (95% CI: 46–61) of adolescents in Kenya and Nepal, respectively, had iron deficiency. In both surveys, anaemia occurred more commonly among adolescents with iron deficiency. Vitamin A deficiency was found in 15% (95% CI: 10–20) of adolescents in Kenya and 30% (95% CI: 24–37) of adolescents in Nepal. Night blindness was not more common in adolescents with vitamin A deficiency than in those without vitamin A deficiency. In Kenya, one of the seven adolescents with Bitot's spots had vitamin A deficiency.

Conclusions

Anaemia, iron deficiency and vitamin A deficiency are common among adolescents in refugee populations. Such adolescents need to increase intakes of these nutrients; however, the lack of routine access makes programmes targeting adolescents difficult. Adolescent refugees should be considered for assessment along with other at-risk groups in displaced populations.

Mortality and morbidity among postpartum HIV-positive and HIV-negative women in Zimbabwe: risk factors, causes, and impact of single-dose postpartum vitamin A supplementation

BACKGROUND

Vitamin A deficiency is common among women in resource-poor countries and is associated with greater mortality during HIV.

METHODS

Fourteen thousand one hundred ten mothers were tested for HIV and randomly administered 400,000 IU vitamin A or placebo at less than 96 hours postpartum. The effects of vitamin A and HIV status on mortality, health care utilization, and serum retinol were evaluated.

RESULTS

Four thousand four hundred ninety-five (31.9%) mothers tested HIV positive. Mortality at 24 months was 2.3 per 1000 person-years and 38.3 per 1000 person-years in HIV-negative and HIV-positive women, respectively. Vitamin A had no effect on mortality. Tuberculosis was the most common cause of death, and nearly all tuberculosis-associated deaths were among HIV-positive women. Among HIV-positive women, vitamin A had no effect on rates of hospitalization or overall sick clinic visits, but did reduce clinic visits for malaria, cracked and bleeding nipples, pelvic inflammatory disease, and vaginal infection. Among HIV-negative women, serum retinol was responsive to vitamin A, but low serum retinol was rare. Among HIV-positive women, serum retinol was largely unresponsive to vitamin A, and regardless of treatment group, the entire serum retinol distribution was shifted 25% less than that of HIV-negative women 6 weeks after dosing.

CONCLUSIONS

Single-dose postpartum vitamin A supplementation had no effect on maternal mortality, perhaps because vitamin A status was adequate in HIV-negative women and apparently unresponsive to supplementation in HIV-positive women.

Vitamin A deficiency disorders in children and women

Vitamin A deficiency is an endemic nutrition problem throughout much of the developing world, especially affecting the health and survival of infants, young children, and pregnant and lactating women. These age and life-stage groups represent periods when both nutrition stress is high and diet likely to be chronically deficient in vitamin A. Approximately 127 million preschool-aged children and 7 million pregnant women are vitamin A deficient. Health consequences of vitamin A deficiency include mild to severe systemic effects on innate and acquired mechanisms of host resistance to infection and growth, increased burden of infectious morbidity, mild to severe (blinding) stages of xerophthalmia, and increased risk of mortality. These consequences are defined as vitamin A deficiency disorders (VADD). Globally, 4.4 million preschool children have xerophthalmia and 6 million mothers suffer night blindness during pregnancy. Both conditions are associated with increased risk of morbidity and mortality. While reductions of child mortality of 19-54% following vitamin A treatment have been widely reported, more recent work suggests that dosing newborns with vitamin A may, in some settings, lower infant mortality. Among women, one large trial has so far reported a > or = 40% reduction in mortality related to pregnancy with weekly, low-dose vitamin A supplementation. Epidemiologic data on vitamin A deficiency disorders can be useful in planning, designing, and targeting interventions.

HIV incidence among post-partum women in Zimbabwe: risk factors and the effect of vitamin A supplementation

OBJECTIVE

To test whether post-partum vitamin A supplementation can reduce incident HIV among post-partum women and identify risk factors for HIV incidence.

DESIGN

Randomized, placebo-controlled trial

METHODS

Between November 1997 and January 2001, 14,110 women were randomly administered 400,000 IU vitamin A or placebo within 96 h post-partum. HIV incidence was monitored among 9562 HIV-negative women.

RESULTS

Cumulative incidence was 3.4% [95% confidence interval (CI), 3.0-3.8] and 6.5% (95% CI, 5.7-7.4) over 12 and 24 months post-partum, respectively. Vitamin A supplementation had no impact on incidence [hazard ratio (HR), 1.08; 95% CI, 0.85-1.38]. However, among 398 women for whom baseline serum retinol was measured, those with levels indicative of deficiency (< 0.7 micromol/l, 9.2% of those measured) were 10.4 (95% CI, 3.0-36.3) times more likely to seroconvert than women with higher concentrations. Furthermore, among women with low serum retinol, vitamin A supplementation tended to be protective against incidence (HR, 0.29; 95% CI, 0.03-2.60; P = 0.26), although not significantly so, perhaps due to limited statistical power. Severe anaemia (haemoglobin < 70 g/l) was associated with a 2.7-fold (95%CI, 1.2-6.1) greater incidence. Younger women were at higher risk of HIV infection: incidence declined by 5.7% (2.8-8.6) with each additional year of age.

CONCLUSION

Among post-partum women, a single large-dose vitamin A supplementation had no effect on incidence, although low serum retinol was a risk factor for seroconversion. Further investigation is required to determine whether vitamin A supplementation of vitamin-A-deficient women or treatment of anaemic women can reduce HIV incidence.

Intraplacental retinol distribution

With the objective of evaluating intraplacental vitamin A distribution, 234 placental samples were collected, corresponding to six samples from each of the placentas analyzed: two from the lateral maternal portion, one from the central maternal portion, two from the lateral fetal portion, and one from the central fetal portion. Samples were obtained from 39 adult puerperal mothers with low-risk pregnancies, without vitamin A deficiency or night blindness. Retinol content determination was achieved through spectrophotometry. Retinol values obtained for each region were correlated with the most probable value for each placenta (P < 0.001). Despite differences in retinol content between samples, statistical data analysis showed that intra-tissue variation had no influence on the conversion of data into information. Consequently, any portion of the placenta may be used for retinol level determination purposes, due to the correlation between all portions and the most probable value. The findings of the present study represent an advance for surveys intending to incorporate the collection and dosage of placental vitamin A levels into their analyses, thus increasing the arsenal of pre-pathological or subclinical vitamin A deficiency markers, which can allow for earlier intervention on the maternal-infant group.

Gender differences in dietary intake among adults of Hindu communities in lowland Nepal: assessment of portion sizes and food consumption frequencies

OBJECTIVE

To elucidate gender differences in dietary intake among adults in lowland Nepalese communities.

SUBJECTS AND METHODS

For 122 male and 195 female subjects aged 20 years and over from 94 randomly selected households, interviews using a 19-item food frequency questionnaire were conducted. To determine the portion sizes of these foods, the samples consumed by 56 subjects in a full 1-day period were weighed. Energy expenditure was estimated by time spent on daily activities.

RESULTS

Gender differences in per-day energy and protein intakes were related to sex differences in body size and energy expenditure. Apparent gender differences in the crude intakes disappeared when they were expressed by nutrient density (mg or microg/MJ) since micronutrient intakes were significantly correlated with energy intake. However, males' iron intake was larger even after adjustment for energy intake, attributing to their larger portion sizes of commonly consumed staple foods and higher frequencies of consuming luxury foods (fish and tea).

CONCLUSION

The intrahousehold unequal distribution of food incurs risk of iron deficiency among female subjects.

SPONSORSHIP

This study was financially supported by the Ajinomoto Foundation for Dietary Culture and the Alliance for Global Sustainability Program.

Association between gestational night blindness and serum retinol in mother/newborn pairs in the city of Rio de Janeiro, Brazil

OBJECTIVE

Gestational night blindness (XN) is associated with increased risk of reproductive morbidity and mortality. This study investigated the prevalence of gestational XN among postpartum women treated in a public maternity hospital in the city of Rio de Janeiro, Brazil and evaluated its association with maternal and neonatal (cord blood) serum retinol concentrations.

METHODS

XN was evaluated retrospectively, using an interview according to guidelines of the World Health Organization, in 222 postpartum women (< or = 6 h after delivery) after singleton births who had low obstetric risk. Serum retinol concentrations were measured according to the modified Bessey method, with a cutoff point lower than 1.05 micromol/L for inadequate serum retinol concentration.

RESULTS

Prevalence of gestational XN was 18%, and inadequate maternal and cord blood serum retinol concentrations were found in 24.4% and 45.5% of samples, respectively. The results associated gestational XN with inadequate maternal serum retinol concentration (P = 0.000), and an association was observed between maternal and neonatal serum retinol concentrations (P = 0.000). A poor association was observed between maternal XN and serum levels of retinol in newborn children (P = 0.06).

CONCLUSIONS

The results suggest that prevalence of gestational XN and inadequate serum retinol concentration among postpartum women and newborns is a concern, calling attention to the need for studies in other parts of Brazil. In addition, the risk of inadequate serum retinol in newborns was significantly higher among infants of postpartum women with serum retinol levels below 1.05 micromol/L. Gestational XN was associated with inadequate levels of maternal serum retinol, and the results suggest a poor relation between maternal XN and vitamin A nutritional status of newborns.

Papel da vitamina A na prevenção do estresse oxidativo em recém-nascidos

A vitamina A é um micronutriente essencial ao ser humano, sobretudo nos momentos de intenso crescimento e desenvolvimento, como a gestação e a infância. Além da atuação dessa vitamina em diversos processos metabólicos, atualmente têm-se destacado o efeito antioxidante desempenhado principalmente pelas formas pró-vitamínicas (carotenóides). Essa função antioxidante da vitamina A é de grande importância no nascimento, período no qual o recém-nascido produz grande quantidade de radicais livres em resposta à exposição a elevadas concentrações de oxigênio. Devido às baixas reservas dessa vitamina, cuja transferência trans-placentária ocorre principalmente no terceiro trimestre de gestação e devido à imaturidade dos demais sistemas antioxidantes, os recém-nascidos prematuros são os mais vulneráveis aos efeitos do estresse decorrente do nascimento. No entanto, ainda existem controvérsias quanto aos benefícios da suplementação da vitamina A no período gestacional, com o objetivo de prevenir a deficiência de vitamina A e suas conseqüências. O presente trabalho tem por objetivo reunir artigos referentes ao tema e publicados em periódicos indexados nas bases de dados MEDLINE e LILACS, no período de 1990 e 2003.

Micronutrient deficiencies in early pregnancy are common, concurrent, and vary by season among rural Nepali pregnant women

Pregnant women in developing countries are vulnerable to multiple micronutrient deficiencies. We investigated their prevalence and seasonal variation as part of a baseline assessment in a population-based, maternal micronutrient supplementation trial conducted in the rural Southeastern plains of Nepal. Serum concentrations of 11 micronutrients were assessed in 1165 pregnant women in the 1st trimester before supplementation. Using defined cutoff values, the prevalence of deficiencies of vitamins A, E, and D were 7, 25, and 14%, respectively. Nearly 33% of the women were deficient in riboflavin, and 40 and 28% had serum vitamin B-6 and B-12 deficiencies, respectively. Only 12% of the women were folate deficient, but 61% were zinc deficient. The prevalence of low serum iron concentration was 40%, and 33% were anemic (hemoglobin < 110 g/L). Multiple micronutrient deficiencies were common among pregnant women. Over 10% of the pregnant women were both anemic and deficient in B-complex vitamins, whereas 22% of women were both anemic and zinc deficient. Only 4% of women had no deficiency, whereas approximately 20% of the women had 2, 3, or 4 deficiencies. Almost 18% of women had >/=5 deficiencies. Micronutrient status varied by season; it was generally best during the winter months, except for serum vitamin D concentration, which peaked during the hot summer and monsoon months. Women in rural South Asia are likely to begin a pregnancy with multiple micronutrient deficiencies that may vary with seasonality in micronutrient-rich food availability.

Vitamin supplementation for preventing miscarriage

BACKGROUND

Miscarriage is a common complication of pregnancy that can be caused by a wide range of factors. Poor dietary intake of vitamins has been associated with an increased risk of miscarriage, therefore supplementing women with vitamins either prior to or in early pregnancy may help prevent miscarriage.

OBJECTIVES

The objectives of this review are to determine the effectiveness and safety of any vitamin supplementation, on the risk of spontaneous miscarriage, maternal adverse outcomes and fetal and infant adverse outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (8 September 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) and MEDLINE (1966 to May 2003), Current Contents (1998 to May 2003) and EMBASE (1980 to May 2003).

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing one or more vitamins with either placebo, other vitamins, no vitamins or other interventions, prior to conception, periconceptionally or in early pregnancy (less than 20 weeks' gestation).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data and assessed trial quality.

MAIN RESULTS

We identified seventeen trials assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome that were eligible for the review. Overall, the included trials involved 35,812 women and 37,353 pregnancies. Two trials were cluster randomised and contributed data for 20,758 women and 22,299 pregnancies in total. No difference was seen between women taking any vitamins compared with controls for total fetal loss (relative risk (RR) 1.05, 95% confidence interval (CI) 0.95 to 1.15), early or late miscarriage (RR 1.08, 95% CI 0.95 to 1.24) or stillbirth (RR 0.85, 95% CI 0.63 to 1.14) and most of the other primary outcomes, using fixed-effect models. For the other primary outcomes, women given any type of vitamin(s) compared with controls were less likely to develop pre-eclampsia (RR 0.68, 95% CI 0.54 to 0.85, four trials, 5580 women) and more likely to have a multiple pregnancy (RR 1.38, 95% CI 1.12 to 1.70, three trials, 20,986 women).

AUTHORS' CONCLUSIONS

Taking vitamin supplements, alone or in combination with other vitamins, prior to pregnancy or in early pregnancy, does not prevent women experiencing miscarriage or stillbirth. However, women taking vitamin supplements may be less likely to develop pre-eclampsia and more likely to have a multiple pregnancy.

Effects of antenatal multiple micronutrient supplementation on birthweight and gestational duration in Nepal: double-blind, randomised controlled trial

BACKGROUND

Neonatal mortality is the biggest contributor to global mortality of children younger than 5 years, and low birthweight is a crucial underlying factor. We tested the hypotheses that antenatal multiple micronutrient supplementation would increase infant birthweight and gestational duration.

METHODS

We did a double-blind, randomised controlled trial in Dhanusha district, Nepal. Women attending for antenatal care with singleton pregnancies at up to 20 weeks' gestation were invited to participate. Participants were randomly allocated either routine iron and folic acid supplements (control; n=600) or a multiple micronutrient supplement providing a recommended daily allowance of 15 vitamins and minerals (intervention; n=600). Supplementation began at a minimum of 12 weeks' gestation and continued until delivery. Primary outcome measures were birthweight and gestational duration. Analysis was by intention to treat. The study is registered as an International Standard Randomised Controlled Trial, number ISRCTN88625934.

FINDINGS

Birthweight was available for 523/600 infants in the control group and 529/600 in the intervention group. Mean birthweight was 2733 g (SD 422) in the control group and 2810 g (453) in the intervention group, representing a mean difference of 77 g (95% CI 24-130; p=0.004) and a relative fall in the proportion of low birthweight by 25%. No difference was recorded in the duration of gestation (0.2 weeks [-0.1 to 0.4]; p=0.12), infant length (0.3 cm [-0.1 to 0.6]; p=0.16), or head circumference (0.2 cm [-0.1 to 0.4]; p=0.18).

INTERPRETATION

In a poor community in Nepal, consumption of a daily supplement containing a recommended daily allowance of 15 micronutrients in the second and third trimesters of pregnancy was associated with increased birthweight when compared with a standard iron and folic acid preparation. The effects on perinatal morbidity and mortality need further comparisons between studies. Published online March 3, 2005 http://image.thelancet.com/extras/04art11045web.pdf.

Recovery from impaired dark adaptation in nightblind pregnant Nepali women who receive small daily doses of vitamin A as amaranth leaves, carrots, goat liver, vitamin A-fortified rice, or retinyl palmitate

BACKGROUND

It is not known whether daily consumption of vitamin A-containing foods is efficacious for treating nightblindness.

OBJECTIVE

We assessed the effect of supplementation with vitamin A from food or synthetic sources on dark adaptation and plasma retinol concentrations in nightblind pregnant Nepali women.

DESIGN

Nightblind pregnant women were randomly assigned to 1 of 6 treatment groups to receive 6 d/wk for 6 wk either 850 microg retinol equivalents/d as retinyl palmitate, vitamin A-fortified rice, goat liver, amaranth leaves, or carrots or 2000 microg retinol equivalents/d as retinyl palmitate. Dark adaptation was assessed weekly by using the pupillary threshold (PT) test; plasma retinol concentrations were measured before and after the intervention. These outcomes were also assessed in a comparison group of nonnightblind pregnant women.

RESULTS

In the nightblind women, the mean PT improved significantly (P<0.0001) from -0.71+/-0.04 to -1.42+/-0.02 log cd/m2, and the final mean PT did not differ significantly from that in the nonnightblind women (-1.43+/-0.04; P=0.55). Improvement in dark adaptation was greater in the liver group than in the vitamin A-fortified rice group (P<0.02). Plasma retinol concentrations increased significantly (P<0.0001) from 0.95+/-0.05 to 1.07+/-0.05 micromol/L. The plasma retinol response was greater in the higher-dose capsule and liver groups than in the vegetable groups and significantly greater in the liver group than in the vitamin A-fortified rice group (both: P<0.05).

CONCLUSION

Improvement in dark adaptation did not differ significantly between women who received vitamin A as liver, amaranth leaves, carrots, or retinyl palmitate.

Community-based interventions for improving perinatal and neonatal health outcomes in developing countries: a review of the evidence

BACKGROUND

Infant and under-5 childhood mortality rates in developing countries have declined significantly in the past 2 to 3 decades. However, 2 critical indicators, maternal and newborn mortality, have hardly changed. World leaders at the United Nations Millennium Summit in September 2000 agreed on a critical goal to reduce deaths of children <5 years by two thirds, but this may be unattainable without halving newborn deaths, which now comprise 40% of all under-5 deaths. Greater emphasis on wide-scale implementation of proven, cost-effective measures is required to save women's and newborns' lives. Approximately 99% of neonatal deaths take place in developing countries, mostly in homes and communities. A comprehensive review of the evidence base for impact of interventions on neonatal health and survival in developing-country communities has not been reported.

OBJECTIVE

This review of community-based antenatal, intrapartum, and postnatal intervention trials in developing countries aimed to identify (1) key behaviors and interventions for which the weight of evidence is sufficient to recommend their inclusion in community-based neonatal care programs and (2) key gaps in knowledge and priority areas for future research and program learning.

METHODS

Available published and unpublished data on the impact of community-based strategies and interventions on perinatal and neonatal health status outcomes were reviewed. Evidence was summarized systematically and categorized into 4 levels of evidence based on study size, location, design, and reported impact, particularly on perinatal or neonatal mortality. The evidence was placed in the context of biological plausibility of the intervention; evidence from relevant developed-country studies; health care program experience in implementation; and recommendations from the World Health Organization and other leading agencies.

RESULTS

A paucity of community-based data was found from developing-country studies on health status impact for many interventions currently being considered for inclusion in neonatal health programs. However, review of the evidence and consideration of the broader context of knowledge, experience, and recommendations regarding these interventions enabled us to categorize them according to the strength of the evidence base and confidence regarding their inclusion now in programs. This article identifies a package of priority interventions to include in programs and formulates research priorities for advancing the state of the art in neonatal health care.

CONCLUSIONS

This review emphasizes some new findings while recommending an integrated approach to safe motherhood and newborn health. The results of this study provide a foundation for policies and programs related to maternal and newborn health and emphasizes the importance of health systems research and evaluation of interventions. The review offers compelling support for using research to identify the most effective measures to save newborn lives. It also may facilitate dialogue with policy makers about the importance of investing in neonatal health.

Níveis séricos de retinol em escolares de 7 a 17 anos no município do Rio de Janeiro

OBJETIVO: Avaliar o estado nutricional quanto à vitamina A em escolares de 7 a 17 anos. Foram analisados 574 escolares, com idade entre 7 e 17 anos, regularmente matriculados na rede municipal de ensino no Rio de Janeiro. MÉTODOS: Os níveis séricos de retinol foram determinados pelo método Bessey-Lowry modificado e o ponto de corte utilizado para caracterizar inadequação sérica de retinol foi <1,05µmol/L. RESULTADO: Encontrou-se um total de 10,30% de escolares com baixos níveis de retinol sérico. Ao considerar a faixa etária, observou-se uma tendência a maiores percentuais de níveis inadequados de retinol sérico entre escolares mais jovens (11,98% na faixa etária de 7 a 10 anos e 7,92% na faixa etária de 10 a 17 anos). CONCLUSÃO: Ainda que os níveis séricos de retinol tendam a elevar-se com a idade, eles ainda são baixos com freqüência suficiente para justificar maior atenção ao segmento populacional mais jovem e tornar pertinente a sua inclusão em programas de combate às deficiências de micronutrientes.

The night vision threshold test is a better predictor of low serum vitamin A concentration than self-reported night blindness in pregnant urban Nepalese women

This study was conducted to validate the night vision threshold test (NVTT) as an indicator of night blindness. A total of 1401 pregnant women from the National Maternity Hospital participated in this study. Women were queried about night blindness and took the NVTT using standardized procedures after 10 min of dark adaptation. Sixteen percent failed the NVTT, but only 6.4% reported having night blindness. Blood samples from women who failed the NVTT (cases) and matched controls indicated the serum vitamin A (SVA) concentration was lower (P < 0.05) in cases (1.19 +/- 0.03 micromol/L) than in controls (1.29 +/- 0.03 micromol/L). The SVA concentrations did not differ between women who reported and did not report night blindness. The SVA concentration was correlated (r = 0.22, P < 0.001) with the NVTT scores. Twenty-five percent of women with an SVA < 0.35 micromol/L reported night blindness while 100% failed the NVTT. Nineteen percent of women with an SVA < 0.70 micromol/L reported night blindness while 73% failed the NVTT. A receiver operating characteristics analysis indicated that the NVTT had greater sensitivity (0.73 vs. 0.19) and less specificity (0.51 vs. 0.87) compared with reported night blindness for women with SVA < 0.70 micromol/L and greater sensitivity (100.0 vs. 0.73) and similar specificity (0.51 vs. 0.50) for women with SVA < 0.35 micromol/L. The NVTT identified women with low SVA and self-reported night blindness was misleading. We provide a preliminary algorithm to predict the population of women with low SVA concentrations.

Listening to "felt needs": investigating genital prolapse in western Nepal

The global prevalence of genital prolapse is estimated to be 2-20% in women under age 45. In Nepal, genital prolapse appears to be widespread, but little published evidence exists to buttress this claim. This paper presents findings of two studies, one ethnographic and one clinic-based, in western Nepal. The ethnographic study involved 16 focus group discussions with 120 community members and key informants, and covered community perceptions and women's experience of prolapse and its perceived causes and consequences. The clinic-based study was conducted among 2,072 women who presented with gynaecological complaints and received a diagnosis. One in four of them had genital prolapse, of whom 95% had self-reported the prolapse. The most commonly perceived causes of prolapse were lifting heavy loads, including in the post-partum period. The adverse effects reported included difficulty urinating, abdominal pain, backache, painful intercourse, burning upon urination, white watery discharge, foul-smelling discharge, itching, and difficulty lifting, sitting, walking and standing. The results confirm prolapse as a significant public health problem in western Nepal. We strongly recommend developing systematic, rotational gynaecological clinics in rural districts, the use of a screening checklist and counselling for prevention and early management of genital prolapse by district health workers for family planning and antenatal patients.

Cigarette smoking during pregnancy in rural Nepal. Risk factors and effects of beta-carotene and vitamin A supplementation

OBJECTIVE

We examined risk factors of smoking and the association between smoking and pregnancy-related and 6-month infant mortality in rural Nepal, where 30% women reported smoking during pregnancy.

DESIGN

Cross-sectional analysis of risk factors associated with smoking status and health consequences of smoking, using prospective data collected as part of a randomized community trial to examine the effect of maternal vitamin A or beta-carotene supplementation on maternal mortality.

SETTING

Rural, southeastern plains of Nepal.

SUBJECTS AND METHODS

A total of 17 767 women contributed at least one pregnancy during 3.5 y of the study. Data on cigarette or bidi (rolled tobacco) smoking were collected using a 7-day recall, twice during pregnancy. Associations between smoking status and maternal diet, morbidity profile, household socioeconomic status and serum concentration of retinol, carotenoids and tocopherols were examined. Further, relative risk (RR) and 95% confidence intervals (CI) were calculated to estimate supplement effects on pregnancy-related mortality, stratified by smoking status during pregnancy.

RESULTS

Smokers were more likely to be older, illiterate and poor compared to nonsmokers. Fruit and vegetable consumption among smokers and nonsmokers did not vary. However, smokers were more likely to consume meat/fish/eggs and less likely to consume milk than nonsmokers. They were also more likely to report symptoms of vaginal bleeding, edema, severe headache and convulsions during pregnancy relative to nonsmokers. Mortality per 100,000 pregnancies appeared to be higher among smokers than nonsmokers in the placebo group (915 vs 584, RR=1.57, 95% CI: 0.80-3.08). beta-Carotene supplementation reduced pregnancy-related mortality both among smokers (RR=0.31 95% CI: 0.11-0.89) and nonsmokers (RR=0.41, 95% CI: 0.19-0.89). Similar results obtained with vitamin A supplementation were not statistically significant. Infant mortality up to 6 months was approximately 30% higher among smokers compared to nonsmokers in the placebo group both before and after adjusting for confounding factors. Neither supplement given to women reduced infant mortality.

CONCLUSIONS

Cigarette smoking during pregnancy is associated with an increased risk of maternal and infant mortality in rural Nepal. beta-Carotene and to some extent vitamin A may reduce the risk of pregnancy-related mortality, but not infant mortality, among both smokers and nonsmokers.

Vitamin A deficiency and xerophthalmia among school-aged children in Southeastern Asia

OBJECTIVE

To determine provisional estimates of the extent of vitamin A (VA) deficiency and xerophthalmia among school-aged children.

DESIGN

Literature search of published, unpublished and website-based population survey and study reports, with country-specific imputation of prevalence rates and numbers of children affected by: (1) VA deficiency based on measured or imputed distributions of serum retinol concentration < 0.70 micromol/l (equivalent to < 20 microg/dl) and (2) xerophthalmia, by country.

SETTING

Countries within the WHO South-East Asian Region.

SUBJECTS

The target group for estimation was children 5-15 y of age.

INTERVENTIONS

None.

RESULTS

The estimated prevalence of VA deficiency is 23.4%, suggesting that there are approximately 83 million VA-deficient school-aged children in the region, of whom 10.9% (9 million, at an overall prevalence of 2.6%) have mild xerophthalmia (night blindness or Bitot's spot). Potentially blinding corneal xerophthalmia appears to be negligible at this age.

CONCLUSIONS

VA deficiency, including mild xerophthalmia, appears to affect large numbers of school-aged children in South-East Asia. However, nationally representative data on the prevalence, risk factors and health consequences of VA deficiency among school-aged children are lacking within the region and globally, representing a future public health research priority.

Risk factors for nightblindness among women of childbearing age in Cambodia

OBJECTIVE

To characterize risk factors for nightblindness among nonpregnant women of childbearing age, a group recently recognized to be at high risk of vitamin A deficiency in some developing countries.

DESIGN

Case-control study.

SETTING

The study included >15 000 households in National Micronutrient Survey of Cambodia conducted in 2000.

SUBJECTS

The prevalence of nightblindness among 13 358 nonpregnant women was 2.0%. A total of 328 nonpregnant women with nightblindness were matched by province with 1009 nonpregnant women without nightblindness.

METHODS

Univariate and multivariate logistic regression models were used to estimate odds ratios (ORs) as estimates of the relative risk of factors associated with nightblindness.

RESULTS

In a final model, materials in the wall of the house (OR 1.4, 95% confidence interval (CI) 0.9-2.0), land ownership < or =0.5 hectares (OR 1.4, 95% CI 1.0-1.9), nightblindness in last pregnancy (OR 44.5, 95% CI 29.2-67.8), parity >3 (OR 1.5, 95% CI 1.0-2.1), diarrhea within the last 2 weeks (OR 1.9, 95% CI 1.3-2.8), maternal body mass index <18.5 (OR 1.8, 95% CI 1.2-2.7), and lack of consumption of vitamin A-rich animal foods in the last 24 h (1-60 retinol equivalents (RE) OR 1.1, 95% CI 0.7-1.6; > or =60 RE, OR 0.7, 95% CI 0.4-1.0) were associated with nightblindness among nonpregnant women.

CONCLUSIONS

Women of childbearing age in Cambodia with low socioeconomic status, low consumption of vitamin A-rich animal foods, a history of nightblindness during the previous pregnancy, parity >3, malnutrition, and diarrhea have a higher risk of nightblindness.

SPONSORSHIP

United States Agency for International Development (442-G-00-95-00515-00).

Vitamin A and infancy. Biochemical, functional, and clinical aspects

Vitamin A is a very intriguing natural compound. The molecule not only has a complex array of physiological functions, but also represents the precursor of promising and powerful new pharmacological agents. Although several aspects of human retinol metabolism, including absorption and tissue delivery, have been clarified, the type and amounts of vitamin A derivatives that are intracellularly produced remain quite elusive. In addition, their precise function and targets still need to be identified. Retinoic acids, undoubtedly, play a major role in explaining activities of retinol, but, recently, a large number of physiological functions have been attributed to different retinoids and to vitamin A itself. One of the primary roles this vitamin plays is in embryogenesis. Almost all steps in organogenesis are controlled by retinoic acids, thus suggesting that retinol is necessary for proper development of embryonic tissues. These considerations point to the dramatic importance of a sufficient intake of vitamin A and explain the consequences if intake of retinol is deficient. However, hypervitaminosis A also has a number of remarkable negative consequences, which, in same cases, could be fatal. Thus, the use of large doses of retinol in the treatment of some human diseases and the use of megavitamin therapy for certain chronic disorders as well as the growing tendency toward vitamin faddism should alert physicians to the possibility of vitamin overdose.

Vitamin A deficiency in poor, urban, lactating women in Bangladesh: factors influencing vitamin A status

AIMS

To investigate the prevalence of vitamin A deficiency among lactating women in a poor urban population of Bangladesh, and to examine the relationship between various factors and vitamin A status.

DESIGN

Cross-sectional study.

SETTING

Maternal and child health clinic in Dhaka City, Bangladesh.

SUBJECTS AND METHODS

A total of 120 lactating women aged 17-37 years were randomly selected from women who attended a local maternal and child health clinic in Dhaka City for immunisation of their children. Various socio-economic, personal characteristics, dietary intakes of vitamin A and anthropometric data were collected. Serum retinol (vitamin A) concentration was determined as a measure of vitamin A status.

RESULTS

Of the subjects, 37% had low serum vitamin A levels (<30 microg x dl-1), with 13.3% having sub-clinical vitamin A deficiency (<20 microg x dl-1). Eighty-seven per cent had vitamin A intakes below the recommended dietary allowance. The lactating women who were either illiterate or received only informal education had significantly lower serum vitamin A levels compared with those who received formal education. The women whose husbands received formal education had significantly higher serum vitamin A levels than those whose husbands were either illiterate or received only informal education. The serum vitamin A levels of women in households with poor sanitation/latrine practice were significantly lower than those of women in households with good sanitation/latrine practice. The women with one child had significantly lower serum vitamin A levels than those with two or more children. Women with a lactation period of 6 months or more had significantly lower serum vitamin A levels than women with a lactation period of less than 6 months. The women who consumed less than the median vitamin A intake (274.8 microg day-1) had significantly lower serum vitamin A levels than those who consumed more than the median vitamin A intake. By multiple regression analysis, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A were found to have significant independent relationships with serum vitamin A. The overall F-ratio (6.8) was highly significant the adjusted R2 was 0.16 (multiple ).

CONCLUSION

A significant proportion of poor, urban, lactating women in Bangladesh have vitamin A deficiency. Among the various factors, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A appear to be important in influencing the vitamin A status of these women.

Micronutrients and reproductive health issues: an international perspective

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

Extent of vitamin A deficiency among preschool children and women of reproductive age

Knowledge of the extent of vitamin A (VA) deficiency (D) is critical for identifying high-risk populations and mobilizing resources for prevention. Yet, all estimates are necessarily imperfect, often based on assumptions in the absence of data. In 1995, the World Health Organization estimated 254 million children to be VA-deficient and 2.8 million to have xerophthalmia. Subsequently, estimates were changed to 75-140 million and 3.3 million, respectively. Although both sets are consistent with a problem of enormous magnitude, the discrepancies also created uncertainty. The present analysis indicates there are approximately 127 million and 4.4 million preschool children with VAD (serum retinol < 0.70 micro mol/L or displaying abnormal impression cytology) and xerophthalmia, respectively. More than 7.2 million pregnant women in the developing world are VA-deficient (serum or breast-milk vitamin A concentrations < 0.70 micro mol/L), and another 13.5 million have low VA status (0.70-1.05 micro mol/L); >6 million women develop night blindness (XN) during pregnancy annually. Roughly 45% of VA-deficient and xerophthalmic children and pregnant women with low-to-deficient VA status live in South and Southeast Asia. These regions harbor >60% of all cases of maternal XN, three fourths of whom seem to live in India. Africa accounts for 25-35% of the global cases of child and maternal VAD; about 10% of all deficient persons live in the eastern Mediterranean region, 5-15% live in the Western Pacific and approximately 5% live in the Region of the Americas. VA prophylaxis seems to be preventing the number of deficient preschool children from increasing while probably reducing rates of blindness and mortality. Greater effort is needed to assess and prevent VAD and its disorders, particularly among pregnant and lactating women.

Process indicators for monitoring and evaluating vitamin A programs

Vitamin A deficiency disorders (VADD) are a major public health problem in many parts of the world and one of the leading underlying causes of childhood mortality. Therefore, VADD control programs can contribute to reaching the international development goal of reducing childhood mortality by two thirds by the year 2015. Although economic development leads to greater food consumption of animal products (the most bioavailable source of vitamin A), other strategies, such as high dose vitamin A capsule supplementation, fortification and food production programs have been developed to tackle the VADD problem independent of economic development efforts. In this article, we discuss the essential role of process indicators in monitoring and fine-tuning VADD control and prevention programs toward ensuring that such programs will be more effective and cost-effective.

Recommendations for indicators: night blindness during pregnancy--a simple tool to assess vitamin A deficiency in a population

Night blindness during pregnancy caused by vitamin A deficiency is associated with an increased risk of morbidity and mortality among women. Because a history of maternal night blindness is simple and reliable to use, it is recommended as a population-based indicator of vitamin A deficiency. Furthermore, a maternal night blindness prevalence of >/=5% is recommended as a cut-off at which vitamin A deficiency may be considered to be a problem of public health significance within the community. This paper provides the justification for these recommendations. Night blindness during pregnancy is strongly associated with low serum and breast milk vitamin A concentration, abnormal conjunctival impression cytology and impaired dark adaptation, which suggests that it is a valid indicator of vitamin A deficiency. The prevalence of night blindness during pregnancy tends to be high in countries where the prevalence of xerophthalmia in children is high and in countries where interventions are in place to reduce childhood vitamin A deficiency. Existing data suggest that misclassification of self-reported maternal night blindness may account for a prevalence of up to 3%. The suggested cut-off, 5%, is set higher than this potential level of false-positive prevalence (3%). Illustrative data from India and Cambodia on childhood xerophthalmia and maternal night blindness rates are used to demonstrate the validity of using a 5% prevalence of maternal night blindness as indicative of a community vitamin A deficiency problem. Finally, it is recommended that night blindness history be elicited for a previous pregnancy that ended in a live birth in the past 3 y, using the local term for night blindness whenever possible.

Recommendations for monitoring and evaluating vitamin A programs: outcome indicators

Monitoring and evaluation are essential components of vitamin A intervention programs. They enable program managers to track progress in achieving their goals. Recommendations for outcome indicators are based on suggestions from the International Vitamin A Consultative Group Meeting (IVACG) workshop in late October 2000 in Annecy, France, followed by a pre-XX IVACG meeting in Hanoi, Vietnam. In areas with detectable xerophthalmia or eye signs, a fall in the prevalence of Bitot's spots to <0.5% and a decrease in night blindness during pregnancy to <5% indicates that vitamin A deficiency (VAD) is no longer a public health problem, although it still may be responsible for excess morbidity and mortality. Pupillary dark adaptation has been proposed as an objective indicator of vitamin A status. A program is considered to have made progress when the mean pupillary threshold improves to better than -1.24 log cd/m(2). For biochemical indices, the shift of mean or median values or the frequency distribution of preschool children with serum retinol concentration below 0.70 micromol (20 microg/dL), lactating mothers with breast milk retinol values below 0.70 micromol (6 microg per g of milk fat) or below 1.05 micromol (8 microg per g of milk fat) are useful to monitor program progress.

Why do children become vitamin A deficient?

Vitamin A deficiency is very prevalent and contributes substantially to morbidity and mortality among young children in developing countries. We identify and quantify three causes of vitamin A deficiency in young children based on data available in the literature: maternal vitamin A deficiency resulting in low concentrations of vitamin A in breast milk, inadequate dietary intake of vitamin A during and after weaning and prevalent illness. We developed a set of recursive equations to estimate the amount of vitamin A in the liver as a function of age over the first 2 y of life. To apply the equations, we selected a best estimate value for each input parameter as the most representative of a typical child in a developing country. Because of the great variability that exists for each variable, we also carried out sensitivity analyses, substituting more extreme values for input parameters. We then estimated stores, assuming a child in a developing country also receives the newly revised vitamin A supplementation regimen recommended by the World Health Organization. Without supplementation, a typical child in a developing country is not able to attain and maintain "minimally adequate" liver vitamin A stores. To overcome this deficit by eating fruits and vegetables alone, the child would need to increase portion sizes about 10-fold. If the child receives the new supplementation regimen, his or her liver stores will still be far short of the average American child (i.e., exceedingly far from toxic levels). However, our estimates indicate that the new supplementation regimen will permit a typical child in a developing country setting to attain minimally adequate vitamin A stores during the first 2 y of life.

Effects of vitamin A deficiency during pregnancy on maternal and child health

OBJECTIVE

To examine the association between biochemical vitamin A deficiency in pregnancy and maternal and fetal health.

DESIGN

A cross sectional clinical study.

SETTING

Antenatal clinic of nutrition unit of Niloufer Hospital catering for a low socio-economic population, and a private nursing home (Swapna nursing home) catering for a high socio-economic population.

POPULATION

736 pregnant women in their third trimester of pregnancy belonging to low (n = 522) and high socio-economic groups (n = 214).

METHODS

All the women were subjected to a detailed clinical, anthropometric and obstetric examination. Night blindness was assessed by administering the standard WHO questionnaire. Birthweight and gestational age of the infants, maternal anaemia and development of pregnancy-induced hypertension in the mother were recorded. Haemoglobin and serum retinol were estimated at the time of recruitment to the study.

MAIN OUTCOME MEASURES

Serum retinol levels, anaemia, pregnancy-induced hypertension, birthweight and gestational age of the infant.

RESULTS

Night blindness was observed in 2.9% of the women and subclincal vitamin A deficiency (serum retinol <20 microg/dL with no clinical signs) in 27% of the women. Moderate to severe anaemia was observed in 41.2% of the women, and 15.8% of the women developed pregnancy-induced hypertension. Sixty-one (9.4%) women delivered preterm. Univariate analysis identified a significant association between serum retinol <20 microg/dL and preterm delivery (OR = 1.74, 95% CI 1.03-2.96), maternal anaemia (OR = 1.82, 95% CI 1.28-2.60) and pregnancy-induced hypertension (OR = 1.56, 95% CI 1.02-2.83). After adjusting for the confounding variables (body mass index, parity, age and socio-economic status) in a multivariate analysis, the significant associations between serum retinol <20 microg/dL and preterm delivery (P = 0.02) and anaemia (P = 0.003) persisted, while that for pregnancy-induced hypertension disappeared (P = 0.71).

CONCLUSION

The study suggests that subclinical vitamin A deficiency is a problem during the third trimester of pregnancy. Serum concentration of retinol <20 microg/dL appears to indicate a deficient status, and is associated with an increased risk of preterm delivery and maternal anaemia.

Dark adaptation pattern of pregnant women as an indicator of functional disturbance at acceptable serum vitamin A levels

BACKGROUND

As a result of lack of precise guidelines, nutritional surveys on adults and high-risk groups are using diverse reference values as a dividing line between normal and deficient vitamin A status.

OBJECTIVE

To investigate whether pregnant women at marginally normal serum retinol status exhibit functional alteration that are characteristic of a deficiency state.

SETTING

Antenatal clinic, Gondar teaching hospital.

SUBJECTS

Ninety-six healthy pregnant women were recruited for the study at the antenatal clinic.

INTERVENTION

The dark adaptation time was tested in 48 pregnant women with marginal serum retinol level. The time lapse to see successive light stimuli of diminishing luminescence grade and change in retinal sensitivity pattern was measured using dark adaptometer. Results were compared with the results of a control group of women of similar age, parity and gestational period but with serum retinol values above 35 microg/dl.

RESULTS

The mean serum retinol levels of cases and controls were 23.35 microg/dl and 40.47 microg/dl respectively (P<0.008). Cases have a lower dark adaptation than their controls, shown by their remarkably reduced sensitivity to light. For instance at mean final light threshold was -2.20+/-0.11 log cd/m(2) in cases as compared to -2.88+/-0.1 log cd/m(2) in the normal group (P<0.001).

CONCLUSION

During pregnancy, dark adaptation was strongly associated with serum retinol concentration and women with marginal vitamin A concentration had lower dark adaptation. Hence marginally normal serum retinol levels should be categorized as a deficiency state, at least in pregnant women.

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.

Vitamin A, infection, and immune function

In populations where vitamin A availability from food is low, infectious diseases can precipitate vitamin A deficiency by decreasing intake, decreasing absorption, and increasing excretion. Infectious diseases that induce the acute-phase response also impair the assessment of vitamin A status by transiently depressing serum retinol concentrations. Vitamin A deficiency impairs innate immunity by impeding normal regeneration of mucosal barriers damaged by infection, and by diminishing the function of neutrophils, macrophages, and natural killer cells. Vitamin A is also required for adaptive immunity and plays a role in the development of T both-helper (Th) cells and B-cells. In particular, vitamin A deficiency diminishes antibody-mediated responses directed by Th2 cells, although some aspects of Th1-mediated immunity are also diminished. These changes in mucosal epithelial regeneration and immune function presumably account for the increased mortality seen in vitamin A-deficient infants, young children, and pregnant women in many areas of the world today.

Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women

BACKGROUND

Zinc deficiency may result in abnormal dark adaptation or night blindness, a symptom primarily of vitamin A deficiency. During a placebo-controlled trial in Nepal, weekly vitamin A supplementation of women reduced but failed to eliminate the incidence of night blindness during pregnancy, suggesting a role for zinc.

OBJECTIVE

The study examined the efficacy of daily zinc supplementation in restoring night vision of pregnant women who developed night blindness while routinely receiving either vitamin A, beta-carotene, or placebo in a field trial.

DESIGN

Women (n = 202) who reported to be night blind during pregnancy were randomly assigned in a double-blind manner, stratified on vitamin A, beta-carotene, or placebo receipt, to receive 25 mg Zn or placebo daily for 3 wk. Thus, the 6 groups studied were as follows: beta-carotene + zinc, beta-carotene alone, vitamin A + zinc, vitamin A alone (vitamin A + placebo), zinc alone (zinc + placebo), and placebo (2 placebos: one for the vitamin A or beta-carotene study and one for the zinc study). Women underwent a clinic-based assessment that included pupillary threshold testing and phlebotomy before and after supplementation. Supplement use and daily history of night blindness were obtained at home twice every week.

RESULTS

Zinc treatment increased serum zinc concentrations, but alone (zinc alone group), failed to restore night vision or to improve dark adaptation. However, women in the vitamin A + zinc group who had baseline serum zinc concentrations <9.9 micromol/L were 4 times more likely to have their night vision restored (95% CI: 1.1, 17.3) than were women in the placebo group and tended to have a small improvement in pupillary threshold scores (by 0.21 log candela/m2; P = 0.09).

CONCLUSION

These data suggest that zinc potentiated the effect of vitamin A in restoring night vision among night-blind pregnant women with low initial serum zinc concentrations.

Maternal night blindness increases risk of mortality in the first 6 months of life among infants in Nepal

Night blindness occurs commonly among women during pregnancy in rural NEPAL: We examined the relationship between maternal night blindness and the risk of mortality occurring among infants in the first 6 mo of life. Stratified analysis by maternal night blindness status during pregnancy was done for 10,000 women participating in a randomized, placebo-controlled trial of vitamin A and beta-carotene supplementation. Mortality of infants of non-night blind women in all three supplementation groups was similar, and when combined, was 63/1000 live births. Relative to this, mortality was higher by 63% [95% confidence interval (CI): 9-138%) and 50% (95% CI: -3 to 133%) among infants of night blind women receiving placebo and beta-carotene, respectively, but only by 14% (95% CI: -33 to 93%) among those receiving vitamin A. Thus, 6-mo mortality was higher among infants of women who had night blindness during pregnancy. Maternal receipt of vitamin A reduced this risk.

Vitamin A supplementation at birth delays pneumococcal colonization in South Indian infants

Nasopharyngeal colonization is a risk factor for pneumococcal disease, a leading cause of complications and death in infants. We assessed the impact of vitamin A supplementation in reducing pneumococcal colonization in infants from an area with endemic vitamin A deficiency. We recruited 464 2-mo-old infants from a rural area in South India. Infants were randomly assigned to receive two 7000-microg retinol equivalent doses of vitamin A (n = 239) or placebo (n = 225) orally at birth, and nasopharyngeal specimens were collected at ages 2, 4 and 6 mo. We studied the effect of vitamin A on culture-confirmed pneumococcal colonization and on the distribution of pneumococcal serotypes. Analyses were conducted by intention-to-treat. The risk of colonization among infants aged 4 mo who were not colonized by age 2 mo was significantly reduced in the vitamin A group compared with the placebo group [odds ratio 0.51 (0.28, 0.92), P = 0.02). The odds of colonization were 27% lower in the treatment group than in the placebo group [odds ratio 0.73 (0.48, 1.1), P = 0.13]. No differences were detected in the prevalence of invasive serotypes. The risk of colonization with penicillin-resistant isolates was 74% lower in the vitamin A group than in the placebo group at 2 mo of age. However, the prevalence of penicillin-resistant isolates was only 4%. Neonatal vitamin A supplementation may play a role in lowering morbidity rates associated with pneumococcal disease by delaying the age at which colonization occurs.

Vitamin A or beta-carotene supplementation reduces symptoms of illness in pregnant and lactating Nepali women

The contribution of nutritional interventions to the reduction in maternal morbidity rates in developing countries is not well known. We assessed the impact of weekly vitamin A and beta-carotene supplementation on the prevalence of pregnancy and postpartum illness symptoms among 15,832 Nepali women in a placebo-controlled, double-masked, cluster-randomized trial. There was no impact of either supplement on morbidity rates reported up to 28 wk of gestation, inclusive. However, in late pregnancy (>28 wk), symptoms of nausea, faintness and night blindness were reduced with vitamin A, but not beta-carotene, supplementation. Vitamin A supplementation shortened the length of labor by 1.5 h 50 min among nulliparous and multiparous women, respectively. Both interventions reduced the postpartum prevalence of at least four loose stools and night blindness. beta-Carotene supplementation also reduced symptoms of high fever postpartum. The mean number of days of any reported illness symptoms was 3-4 per wk throughout pregnancy. Among women receiving vitamin A, the total number of days of illness symptoms accrued over the last 12 wk of pregnancy was lower by 5 d compared with the placebo recipients. We found the burden of pregnancy-related illness symptoms to be high in this rural area of Nepal where antenatal care is poor and most deliveries occur at home. Maternal vitamin A or beta-carotene supplementation resulted in a reduction in the prevalence of selected illness symptoms during late pregnancy, at the time of birth and during 6 mo postpartum, suggesting that a diet adequate in vitamin A may be important for improving women's reproductive health.

Molecular genetics of Oguchi disease, fundus albipunctatus, and other forms of stationary night blindness: LVII Edward Jackson Memorial Lecture

PURPOSE

To compare the clinical findings of the various forms of stationary night blindness caused by mutations in identified genes encoding proteins of photoreceptors or the retinal pigment epithelium.

METHODS

Review of the visual acuities, visual fields, fundi, dark-adaptation curves, and electroretinograms from patients with stationary night blindness caused by mutations in the genes RHO, GNAT1, PDE6B, RHOK, SAG, RDH5, and CACNA1F, respectively encoding rhodopsin, the alpha subunit of rod transducin, the beta subunit of rod cGMP-phosphodiesterase, rhodopsin kinase, arrestin, 11-cis retinol dehydrogenase, and a retinal L-type calcium channel.

RESULTS

In the evaluated forms of stationary night blindness, the time course of dark adaptation and the characteristics of the electroretinogram indicate that rod photoreceptors are present and that they function, although abnormally. In night blindness resulting from defects in rhodopsin, the alpha subunit of rod transducin, or the beta subunit of rod cGMP phosphodiesterase, rod photoreceptors respond only to light intensities far brighter than normal, and the sensitivity of rods to light is similar to that of normal individuals who are not dark adapted. In fundus albipunctatus and in Oguchi disease, the rod photoreceptors can achieve normal sensitivity to dim light but only after 2 or more hours of dark adaptation, compared with approximately 0.5 hours for normal individuals. In each of these forms of stationary night blindness, the poor rod sensitivity and the time course of dark adaptation correlate with the known or presumed physiologic abnormalities caused by the identified gene defects. Patients with some forms of stationary night blindness, such as fundus albipunctatus and Oguchi disease, may develop degeneration of the retina leading to severe loss of vision in later life.

CONCLUSIONS

The identification of the mutant genes causing forms of stationary night blindness refines the classification of these diseases and enhances our understanding of the underlying physiologic defects. Ophthalmologists must be aware that although these diseases are traditionally categorized as "stationary," some of them lead to reduced visual acuity or constricted visual fields, especially in older patients. Efforts to develop therapies for these diseases should concentrate on these more severe forms.

Responsiveness of dark-adaptation threshold to vitamin A and beta-carotene supplementation in pregnant and lactating women in Nepal

BACKGROUND

Impaired dark adaptation occurs commonly in vitamin A deficiency.

OBJECTIVE

We sought to examine the responsiveness of dark-adaptation threshold to vitamin A and beta-carotene supplementation in Nepali women.

DESIGN

The dark-adapted pupillary response was tested in 298 pregnant women aged 15-45 y in a placebo-controlled trial of vitamin A and beta-carotene; 131 of these women were also tested at 3 mo postpartum. Results were compared with those for 100 nonpregnant US women of similar age. The amount of light required for pupillary constriction was recorded after bleaching and dark adaptation.

RESULTS

Pregnant women receiving vitamin A had better dark-adaptation thresholds (-1.24 log cd/m(2)) than did those receiving placebo (-1.11 log cd/m(2); P: = 0. 03) or beta-carotene (-1.13 log cd/m(2); P: = 0.05) (t tests with Bonferroni correction). Dark-adaptation threshold was associated with serum retinol concentration in pregnant women receiving placebo (P: = 0.001) and in those receiving beta-carotene (P: = 0.003) but not in those receiving vitamin A. Among women receiving placebo, mean dark-adaptation thresholds were better during the first trimester (-1.23 log cd/m(2)) than during the second and third trimesters (-1.03 log cd/m(2); P: = 0.02, t test). The mean threshold of nonpregnant US women (-1.35 log cd/m(2)) was better than that of all 3 Nepali groups (P: < 0.001, t test, for all 3 groups).

CONCLUSIONS

During pregnancy, pupillary dark adaptation was strongly associated with serum retinol concentration and improved significantly in response to vitamin A supplementation. This noninvasive testing technique is a valid indicator of population vitamin A status in women of reproductive age.