***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Results from observational studies suggest that micronutrient status is a determinant of the progression of human immunodeficiency virus ( HIV ) disease . METHODS We enrolled 1078 pregnant women infected with HIV in a double-blind , placebo-controlled trial in Dar es Salaam , Tanzania , to examine the effects of daily supplements of vitamin A ( preformed vitamin A and beta carotene ) , multivitamins ( vitamins B , C , and E ) , or both on progression of HIV disease , using survival  models . The median follow-up with respect to survival was 71 months ( interquartile range , 46 to 80 ) . RESULTS Of 271 women who received multivitamins  , 67 had progression to World Health Organization ( WHO ) stage 4 disease or died -- the primary outcome --as compared with 83 of 267 women who received placebo ( 24.7 percent vs. 31.1 percent ; relative risk , 0.71 ; 95 percent confidence interval , 0.51 to 0.98 ; P=0.04 ) . This regimen was also associated with reductions in the relative risk of death related to the acquired immunodeficiency syndrome ( 0.73 ; 95 percent confidence interval , 0.51 to 1.04 ; P=0.09 ) , progression to WHO stage 4 ( 0.50 ; 95 percent confidence interval , 0.28 to 0.90 ; P=0.02 ) , or progression to stage 3 or higher ( 0.72 ; 95 percent confidence interval , 0.58 to 0.90 ; P=0.003 ) . Multivitamins also result ed in significantly higher CD4 + and CD8 + cell counts and significantly lower viral loads . The effects of receiving vitamin A alone were smaller and for the most part not significantly different from those produced by placebo . Adding vitamin A to the multivitamin regimen reduced the benefit with regard to some of the end points examined . CONCLUSIONS Multivitamin supplements delay the progression of HIV disease and provide an effective , low-cost means of delaying the initiation of antiretroviral therapy in HIV-infected women The effects of maternal postpartum vitamin A or beta-carotene supplementation  on  maternal and infant serum retinol concentrations , modified relative dose-response ( MRDR ) ratios and breast milk vitamin A concentrations were assessed during a community-based trial in Matlab , Bangladesh . At 1 - 3 wk postpartum , women were r and omly assigned to receive either ( 1 ) a single dose of 200,000 international units [ 60,000 retinol equivalents ( RE ) ] vitamin A followed by daily placebos ( n = 74 ) , ( 2 ) daily doses of beta-carotene [ 7.8 mg ( 1300 RE ) ] ( n = 73 ) or ( 3 ) daily placebos ( n = 73 ) until 9 mo postpartum . Compared to placebos , vitamin A supplementation result ed in lower maternal MRDR ratios ( i.e. , increased liver stores ) and higher milk vitamin A concentrations at 3 mo , but these improvements were not sustained . The beta-carotene supplementation acted more slowly , result ing in milk vitamin A concentrations higher than the placebo group only at 9 mo . Irrespective of treatment group , over 50 % of women produced milk with low vitamin A concentrations ( < /=1.05 micromol/L or < /=0.28 micromol/g fat ) throughout the study . Overall , mean maternal serum retinol concentrations were not affected by supplementation . Compared to the placebo group , the mean MRDR ratio of 6-mo-old infants was higher in the vitamin A group . Infants ( 33 % ) had serum retinol concentrations < 0.70 micromol/L and 88 % had MRDR ratios > /=0 . 06 . We conclude that while both interventions were beneficial , neither was sufficient to correct the underlying sub clinical vitamin A deficiency in these women nor to bring their infants into adequate vitamin A status BACKGROUND Multiple micronutrient deficiencies may contribute to low birth weight , which is a major global determinant of mortality . OBJECTIVE We assessed the effect of prenatal multimicronutrient supplementation on gestational length and birth size . DESIGN We conducted a r and omized , placebo-controlled , double-blind effectiveness trial among antenatal care attendees in Harare , Zimbabwe . Pregnant women ( 22 - 35 wk of gestation ) were r and omly allocated to receive a multimicronutrient or placebo supplement daily until delivery . Supplementation with iron and folic acid was part of antenatal care . RESULTS Of 1669 women , birth data were available from 1106 ( 66 % ) , of whom 360 ( 33 % ) had HIV infection . The mean gestational length was 39.1 wk , and 16.6 % of the women had a gestational length < 37 wk . The mean birth weight was 3030 g , and 10.5 % of the infants had a birth weight < 2500 g. Multimicronutrient supplementation was associated with tendencies for increased gestational length ( 0.3 wk ; 95 % CI : -0.04 , 0.6 wk ; P = 0.06 ) , birth weight ( 49 g ; -6 , 104 g ; P = 0.08 ) , and head circumference ( 0.2 cm ; -0.02 , 0.4 cm ; P = 0.07 ) but was not associated with low birth weight ( birth weight < 2500 g ) ( relative risk : 0.84 ; 0.59 , 1.18 ; P = 0.31 ) . The effect of multimicronutrient supplementation on birth weight was not significantly different between HIV-uninfected ( 26 g ; -38 , 91 g ) and HIV-infected ( 101 g ; -3 , 205 g ) subjects ( interaction , P > 0.10 ) . CONCLUSION Antenatal multimicronutrient supplementation may be one strategy to increase birth size BACKGROUND Young infants are at risk of vitamin A deficiency . Supplementation of breastfeeding mothers improves the vitamin A status of their infants , but there are no data regarding its effect on infant mortality , and data on the effect of directly supplementing infants during the first few weeks of life are conflicting . OBJECTIVE The objective was to measure the effect on infant mortality of supplementing neonates and their HIV-negative mothers with single , large doses of vitamin A during the immediate postpartum period . DESIGN A r and omized , placebo-controlled , 2-by-2 factorial design trial was conducted in 14,110 mothers and their infants ; 9208 of the mothers were HIV-negative at delivery , remained such during the postpartum year , and were retained in the current analysis . The infants were r and omly assigned within 96 h of delivery to 1 of 4 treatment groups : mothers and infants received vitamin A ( Aa ) , mothers received vitamin A and infants received placebo ( Ap ) , mothers received placebo and infants received vitamin A ( Pa ) , and both mothers and infants received placebo ( Pp ) . The vitamin A dose in the mothers was 400,000 IU and in the infants was 50,000 IU . The mother-infant pairs were followed to 12 mo . RESULTS Hazard ratios ( 95 % CI ) for 12 mo mortality among infants in the maternal-supplemented and infant-supplemented groups were 1.17 ( 0.87 , 1.58 ) and 1.08 ( 0.80 , 1.46 ) , respectively . Hazard ratios ( 95 % CI ) for the Aa , Ap , and Pa groups compared with the Pp group were 1.28 ( 0.83 , 1.98 ) , 1.27 ( 0.82 , 1.97 ) , and 1.18 ( 0.76 , 1.83 ) , respectively . These data indicate no overall effect . Serum retinol concentrations among a sub sample of women were similar to reference norms . CONCLUSION Postpartum maternal or neonatal vitamin A supplementation may not reduce infant mortality in infants of HIV-negative women with an apparently adequate vitamin A status BACKGROUND Linear growth retardation and wasting are common in children born to HIV-infected women . Inexpensive interventions that could improve the postnatal growth pattern of such children are needed . OBJECTIVE The objective was to examine the effect of supplementing HIV-infected women with multivitamins or vitamin A and beta-carotene , during and after pregnancy , on the growth of their children during the first 2 y of life . DESIGN We conducted a r and omized placebo-controlled trial in 886 mother-infant pairs in Tanzania . At the first prenatal visit , HIV-infected women were r and omly assigned to 1 of 4 daily oral regimens in a 2 x 2 factorial fashion : multivitamins ( MV : thiamine , riboflavin , vitamin B-6 , niacin , vitamin B-12 , vitamin C , vitamin E , and folic acid ) , preformed vitamin A + beta-carotene ( VA/BC ) , MV including VA/BC , or placebo . Supplementation continued during the first 2 y postpartum and thereafter . Children were weighed and measured monthly , and all received vitamin A supplements after 6 mo of age per the st and ard of care . RESULTS Multivitamins had a significant positive effect on attained weight ( 459 g ; 95 % CI : 35 , 882 ; P = 0.03 ) and on weight-for-age ( 0.42 ; 95 % CI : 0.07 , 0.77 ; P = 0.02 ) and weight-for-length ( 0.38 ; 95 % CI : 0.07 , 0.68 ; P = 0.01 ) z scores at 24 mo . VA/BC seemed to reduce the benefits of MV on these outcomes . No significant effects were observed on length , midupper arm circumference , or head circumference . CONCLUSION Supplementation of HIV-infected women with multivitamins ( vitamin B complex , vitamin C , and vitamin E ) during pregnancy and lactation is an effective intervention for improving ponderal growth in children Breast milk vitamin A is not well characterized as an indicator of vitamin A status in women with infections . A controlled trial of vitamin A , 3 mg retinol equivalent/day , was conducted among 697 pregnant women with human immunodeficiency virus ( HIV ) infection in Malawi which allowed comparison of plasma versus breast milk vitamin A as indicators of vitamin A status .  Retinol concentrations were measured in plasma at baseline ( 18 - 28 weeks ) and 38 weeks gestation and breast milk at 6 weeks post-partum . Plasma alpha 1-acid glycoprotein ( AGP ) and C-reactive protein ( CRP ) were measured at baseline . Plasma retinol ( geometric mean , SD ) at 38 weeks was 0.72 ( 0.44 , 1.18 ) and 0.61 ( 0.38 , 0.98 ) mumol/L ( P < 0.0002 ) and breast milk retinol was 1.32 ( 0.71 , 2.43 ) and 0.95 ( 0.49 , 1.82 ) mumol/L ( P < 0.0001 ) in vitamin A and placebo groups , respectively . Women with elevated acute phase protein ( AGP > 1 gm/L and /or CRP > 5 mg/L ) at baseline who received vitamin A had significantly higher plasma and breast milk vitamin A  at follow-up compared with placebo .  Elevated acute phase proteins did not distinguish women with low body stores of vitamin A. Breast milk retinol appears to be a better indicator of vitamin A status than plasma retinol in women with infections Objective : To identify factors associated with mother-to-child HIV-1 transmission ( MTCT ) from mothers receiving antenatal antiretroviral therapy .  Design : The French Perinatal Cohort ( EPF ) , a multicenter prospect i ve cohort of HIV-infected pregnant women and their children . Methods : Univariate analysis and logistic regression , with child HIV status as dependent variable , were conducted among 5271 mothers who received antiretroviral therapy during pregnancy , delivered between 1997 and 2004 and did not breastfeed . Results : The MTCT rate was 1.3 % [ 67/5271 ; 95 % confidence interval ( CI ) , 1.0–1.6 ] . It was as low as 0.4 % ( 5/1338 ; 95 % CI , 0.1–0.9 ) in term births with maternal HIV-1 RNA level at delivery below 50 copies/ml . MTCT increased with viral load , short duration of antiretroviral therapy , female gender and severe premature delivery : 6.6 % before 33 weeks versus 1.2 % at 37 weeks or more ( P < 0.001 ) . The type of antiretroviral therapy was not associated with transmission . Intrapartum therapy was associated with four-fold lower MTCT ( P = 0.04 ) in case of v 
    Output:
    
Current best evidence shows that antenatal or postpartum vitamin A supplementation probably has little or no effect on mother-to-child transmission of HIV .