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1.
BACKGROUND: Anemia is a frequent complication among HIV-infected persons and is associated with faster disease progression and mortality. OBJECTIVE: We examined the effect of multivitamin supplementation on hemoglobin concentrations and the risk of anemia among HIV-infected pregnant women and their children. DESIGN: HIV-1-infected pregnant women (n = 1078) from Dar es Salaam, Tanzania, were enrolled in a double-blind trial and provided daily supplements of preformed vitamin A and beta-carotene, multivitamins (vitamins B, C, and E), preformed vitamin A and beta-carotene + multivitamins, or placebo. All women received iron and folate supplements only during pregnancy according to local standard of care. The median follow-up time for hemoglobin measurement for mothers was 57.3 mo [interquartile range (IQR): 28.6-66.8] and for children it was 28.0 mo (IQR: 5.3-41.7). RESULTS: During the whole period, hemoglobin concentrations among women who received multivitamins were 0.33 g/dL higher than among women who did not receive multivitamins (P=0.07). Compared with placebo, multivitamin supplementation resulted in a hemoglobin increase of 0.59 g/dL during the first 2 y after enrollment (P=0.0002). Compared with placebo, the children born to mothers who received multivitamins had a reduced risk of anemia. In this group, the risk of macrocytic anemia was 63% lower than in the placebo group (relative risk: 0.37: 95% CI: 0.18, 0.79; P=0.01). CONCLUSION: Multivitamin supplementation provided during pregnancy and in the postpartum period resulted in significant improvements in hematologic status among HIV-infected women and their children, which provides further support for the value of multivitamin supplementation in HIV-infected adults.  相似文献   

2.
Hypertension during pregnancy increases fetal growth retardation, preterm deliveries, and perinatal deaths, and yet its causes remain unclear. In HIV-infected women, preterm birth additionally increases the risk of HIV transmission to the infant. Oxidative stress and endothelial cell dysfunction of the placenta have been implicated in the development of hypertension during pregnancy. Vitamin intake can reduce oxidative stress and improve endothelial function. We therefore evaluated the effect of multivitamin (20 mg thiamine, 20 mg riboflavin, 25 mg B-6, 50 microg B-12, 500 mg C, 30 mg E, and 0.8 mg folic acid) and vitamin A supplements (30 mg beta-carotene plus 5000 IU preformed vitamin A) in relation to hypertension during pregnancy (systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg at any time during pregnancy). In a double-blind, placebo-controlled, randomized, clinical trial, conducted among 1078 HIV-positive pregnant Tanzanian women, those who received multivitamins were 38% less likely to develop hypertension during pregnancy than those who did not [relative risk (RR) = 0.62, 95% CI 0.40-0.94, P = 0.03]. There was no overall effect of vitamin A on hypertension during pregnancy (RR = 1.00, 95% CI 0.66-1.51, P = 0.98). Hypertension during pregnancy was more likely in women with high baseline systolic blood pressure (>120 vs. < or = 120 mm Hg) (RR = 6.02, 95%CI 2.59-13.97, P < 0.001), and those with higher mid-upper arm circumference (RR = 1.12, 95% CI 1.04-1.19, P = 0.002). Taking multivitamins containing vitamins B, C, and E during pregnancy may be an inexpensive and effective strategy to improve the health of the mother and baby.  相似文献   

3.
BACKGROUND: Wasting is a strong independent predictor of mortality in HIV-infected persons. Vitamin supplements delay the disease progression, but their effect on wasting is not known. Data are lacking on the risk factors for wasting in African HIV-infected persons. OBJECTIVES: The objectives were to examine the effect of vitamin supplements on wasting in HIV-infected women and to assess the effects of sociodemographic characteristics, morbidity events, and immunologic progression on the risk of wasting. DESIGN: HIV-infected women (n = 1078) from Tanzania were randomly assigned to receive 1 of 4 daily oral regimens: multivitamins (B complex, C, and E), vitamin A plus beta-carotene, multivitamins that included vitamin A plus beta-carotene, or placebo. The endpoints of the study included first episodes of a midupper arm circumference <22 cm or a body mass index (BMI; in kg/m2) <18 and the incidence of weight loss episodes during a median 5.3 y of follow-up. RESULTS: Multivitamins alone significantly reduced the risk of a first episode of a midupper arm circumference <22 cm (relative risk: 0.66; 95% CI: 0.47, 0.94; P = 0.02). In multivariate-adjusted Cox models, the woman's age, education level, and height were inversely related to the incidence of wasting. Episodes of diarrhea, nausea or vomiting, lower respiratory tract infections, oral ulcers, thrush, severe anemia, and low CD4+ cell counts were each significantly related to an increased risk of wasting. CONCLUSIONS: Vitamins C and E and the vitamin B complex have a protective effect on wasting in HIV-infected women. Prevention of diarrhea, severe respiratory tract infections, and anemia are likely to decrease the burden of wasting.  相似文献   

4.
BACKGROUND: The pattern of weight gain during pregnancy among HIV-infected women is largely unknown. Multivitamin supplementation was shown to be effective in preventing adverse pregnancy outcomes among HIV-positive women. These protective effects could be mediated in part by an improvement in the pattern of gestational weight gain. OBJECTIVE: We examined the effects of multivitamin and vitamin A supplements on weight gain during the second and third trimesters of pregnancy among HIV-infected women. DESIGN: We enrolled 1075 pregnant, HIV-1-positive women from Dar es Salaam, Tanzania, in a randomized, placebo-controlled trial. Using a 2-by-2 factorial design, we assigned each woman to 1 of 4 regimens: multivitamins (thiamine, riboflavin, niacin, folic acid, and vitamins B-6, B-12, C, and E), vitamin A, multivitamins including vitamin A, or placebo. The women took these oral supplements daily and were weighed monthly until the end of pregnancy. RESULTS: The mean rate of weight gain was 306 g/wk during the second trimester and 247 g/wk during the third trimester. During the third trimester, average weight gain was significantly greater (by 304 g; 95% CI: 17, 590; P = 0.04) and the risk of low rate of weight gain (相似文献   

5.
The authors evaluated the association between use of individual supplements of vitamins A, C, and E only and multivitamins and fatal non-Hodgkin's lymphoma in a large prospective mortality study of US men and women. During 14 years of follow-up (1982-1996), 1,571 non-Hodgkin's lymphoma deaths among 508,351 men and 1,398 non-Hodgkin's lymphoma deaths among 676,306 women were documented. Long-term regular use of individual supplements of vitamins A, C, and E only and multivitamins was unrelated to fatal non-Hodgkin's lymphoma among either men or women. The multivariate relative risks for men who used supplements for 10 or more years were 1.03 (95% confidence interval (CI): 0.54, 2.00) for vitamin A supplements, 1.04 (95% CI: 0.78, 1.39) for vitamin C supplements, 1.06 (95% CI: 0.74, 1.51) for vitamin E supplements, and 1.14 (95% CI: 0.92, 1.40) for multivitamins. The multivariate relative risks for women who used supplements for 10 or more years were 1.40 (95% CI: 0.77, 2.54) for vitamin A supplements, 1.19 (95% CI: 0.89, 1.60) for vitamin C supplements, 1.27 (95% CI: 0.87, 1.84) for vitamin E supplements, and 1.21 (95% CI: 0.98, 1.50) for multivitamins. All associations became weaker when vitamin supplements were mutually adjusted. These findings do not support an important relation between long-term regular use of individual supplements of vitamins A, C, and E only and multivitamins and fatal non-Hodgkin's lymphoma.  相似文献   

6.
BACKGROUND: In vitamin A-deficient populations, children hospitalized with infections and/or malnutrition are at particular risk of developing severe vitamin A (VA) deficiency. High-dose VA supplements are recommended as part of the treatment but results on its effect on recovery from morbidity and on prevention from nosocomial morbidity are conflicting. OBJECTIVE: We aimed to assess the effect of a single high dose and daily low dose of VA on hospitalized malnourished children's morbidity. DESIGN: We carried out a double-blind, randomized trial in 604 and 610 Senegalese hospitalized children. The first mentioned batch received a high-dose VA supplement (200,000 IU) on admission, the second a daily low-dose VA supplement (5000 IU per day) during hospitalization. Children were followed up until discharged. Data on all-cause morbidity were collected daily. RESULTS: Survival analysis showed that the incidence of respiratory disease was significantly lower in the low-dose group than in the high-dose group, hazard ratios (HR): 0.26, 95% CI: 0.07-0.92. The duration of respiratory infection was also significantly lower in the low-dose group than in the high-dose group (HR of cure: 1.41, 95% CI: 1.05-1.89). Duration and incidence of diarrhoea were not significantly different between treatment groups. In children with oedema on admission, mortality was significantly lower in the low-dose group (Adjusted odds ratio: 0.21; 95% CI: 0.05-0.99). CONCLUSIONS: Daily low dose of VA compared with single high dose significantly reduced duration and incidence of respiratory infection but not of diarrhoea in hospitalized children.  相似文献   

7.
Night blindness due to vitamin A deficiency is common during pregnancy among women in Nepal. The authors assessed the risk of maternal death during and after a pregnancy with night blindness among women participating in a cluster-randomized, placebo-controlled vitamin A and beta-carotene supplementation trial in Nepal from July 1994 to September 1997. Subjects were 877 women with night blindness and 9,545 women without night blindness during pregnancy. Women were followed from the time they declared that they were pregnant through the end of the study, representing a median follow-up of 90 weeks (interquartile range: 64-121 weeks). Mortality of night-blind women in the placebo group was 3,601 per 100,000 pregnancies. In comparison, the relative risk of dying among nonnight-blind women in the placebo group was 0.26 (95% confidence interval (CI): 0.13, 0.55), and the relative risk among women with or without night blindness in the vitamin A/beta-carotene group was 0.32 (95% CI: 0.10, 0.91) and 0.18 (95% CI: 0.09, 0.36), respectively. Night-blind women were five times (95% CI: 2.20, 10.58) more likely to die from infections than were women who were not night blind. These findings show that night blindness during pregnancy is a risk factor of both short- and long-term mortality among women. Vitamin A/beta-carotene supplementation ameliorates this risk to a large extent.  相似文献   

8.
OBJECTIVE: We examined whether supplementation with vitamin A and/or vitamins B, C, and E to HIV-infected women during pregnancy and lactation is related to increased concentrations of vitamins A, B12, and E in their infants during the first 6 months of life. DESIGN: We carried out a randomized clinical trial among 716 mother-infant pairs in Dar-es-Salaam, Tanzania. Women were randomly allocated to receive a daily oral dose of one of four regimens: vitamin A, multivitamins (B, C, and E), multivitamins including A, or placebo. Supplementation started at first prenatal visit and continued after delivery throughout the breastfeeding period. The serum concentration of vitamins A, E and B12 was measured in infants at 6 weeks and 6 months postpartum. RESULTS: Maternal vitamin A supplementation increased serum retinol in the infants at 6 weeks (mean difference=0.09 micromol/l, P<0.0001) and 6 months (mean difference=0.06 micromol/l, P=0.0002), and decreased the prevalence of vitamin A deficiency, but had no impact on serum vitamins E or B12. Multivitamins increased serum vitamin B12 at 6 weeks and 6 months (mean differences=176 pmol/l, P<0.0001 and 127 pmol/l, P<0.0001, respectively) and vitamin E (mean differences=1.8 micromol/l, P=0.0008 and 1.1 micromol/l, P=0.004, respectively) and decreased the prevalence of vitamin B12 deficiency. CONCLUSIONS: Vitamin supplementation to HIV-1-infected women is effective in improving the vitamin status of infants during the first 6 months of age.  相似文献   

9.
Daily folic acid (FA) supplementation improves folate status, lowers circulating homocysteine (Hcy) concentrations, and reduces the risk of neural tube defects. Little is known about the efficacy of weekly FA supplementation. The objective of this study was to compare the efficacy of weekly and daily FA supplementations in improving folate and vitamin B-12 status and lowering Hcy concentrations in healthy reproductive-aged women. A randomized, double-blind supplementation trial was conducted in Guatemala. A total of 459 women were assigned randomly to 4 groups to receive weekly (5000 or 2800 microg) or daily (400 or 200 microg) FA for 12 wk. Daily and weekly iron, zinc, and vitamin B-12 were also provided. We determined serum and RBC folate by microbiological assays, but the latter was available only at baseline. Serum Hcy and vitamin B-12 were also measured. We used generalized linear regression models to assess the effects of treatment on biochemical indicators. Supplementation improved folate status similarly across all 4 groups. Overall, mean serum folate concentrations increased by 15.4 nmol/L (95% CI: 13.8, 16.9) and the geometric mean serum Hcy concentration decreased by 9.8% (95% CI: -12.3, -7.1). Daily supplementation improved serum vitamin B-12 by 20% (95% CI: 8, 33.2), whereas weekly supplementation had no effect. In conclusion, weekly FA (either high or low dose) plus vitamin B-12 may be as efficacious as daily supplementation in improving serum folate and lowering Hcy concentrations in healthy women of reproductive age.  相似文献   

10.
BACKGROUND: The effect of vitamin A supplementation on the survival of infants aged <6 mo is unclear. Because most infant deaths occur in the first few month of life, maternal supplementation may improve infant survival. OBJECTIVES: The objective was to assess the effect of maternal vitamin A or beta-carotene supplementation on fetal loss and survival of infants <6 mo of age. DESIGN: Married women of reproductive age in 270 wards of Sarlahi district, Nepal, were eligible to participate. Wards were randomly assigned to have women receive weekly doses of 7000 microg retinol equivalents as retinyl palmitate (vitamin A), 42 mg all-trans-beta-carotene, or placebo. Pregnancies were followed until miscarriage, stillbirth, maternal death, or live birth of one or more infants, who were followed through 24 wk of age. RESULTS: A total of 43559 women were enrolled; 15832 contributed 17373 pregnancies and 15987 live born infants to the trial. The rate of fetal loss was 92.0/1000 pregnancies in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.06 (95% CI: 0.91, 1.25) and 1.03 (95% CI: 0.87, 1.19), respectively. The 24-wk mortality rate was 70.8/1000 live births in the placebo group, comparable with rates in the vitamin A and beta-carotene groups, which had relative risks of 1.05 (95% CI: 0.87, 1.25) and 1.03 (95% CI: 0.86, 1.22), respectively. CONCLUSIONS: Small weekly doses of vitamin A or beta-carotene given to women before conception, during pregnancy, and through 24 wk postpartum did not improve fetal or early infant survival in Nepal.  相似文献   

11.
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.  相似文献   

12.
BACKGROUND: The associations between homocysteine, B vitamin status, and pregnancy outcomes have not been examined prospectively. OBJECTIVE: We assessed the associations of preconception homocysteine and B vitamin status with preterm birth and birth of low-birth-weight (LBW) and small-for-gestational-age (SGA) infants in Chinese women. DESIGN: This was a case-control study of women aged 21-34 y. Preterm cases (n = 29) delivered living infants at <37 wk gestation; term controls (n = 405) delivered infants at > or =37 wk. LBW cases (n = 33) had infants weighing <2500 g; normal-birth-weight controls (n = 390) had infants weighing > or =2500 g. SGA cases (n = 65) had infants below the 10th percentile of weight-for-gestational-age; appropriate-for-gestational-age controls (n = 358) had infants above this cutoff. Nonfasting plasma concentrations of homocysteine, folate, and vitamins B-6 and B-12 were measured before conception. RESULTS: Elevated homocysteine (> or =12.4 micro mol/L) was associated with a nearly 4-fold higher risk of preterm birth (OR: 3.6; 95% CI: 1.3, 10.0; P < 0.05). The risk of preterm birth was 60% lower among women with vitamin B-12 > or =258 pmol/L than among vitamin B-12-deficient women (OR: 0.4; 95% CI: 0.2, 0.9; P < 0.05) and was 50% lower among women with vitamin B-6 > or =30 nmol/L than among vitamin B-6-deficient women (OR: 0.5; 95% CI: 0.2, 1.2; NS). Folate status was not associated with preterm birth, and homocysteine and B vitamin status were not associated with LBW or SGA status. CONCLUSIONS: Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth. These results need to be confirmed in larger prospective studies.  相似文献   

13.
BACKGROUND: Deficiencies of vitamin A, iron, and zinc are prevalent in women and infants in developing countries. Supplementation during pregnancy can benefit mother and infant. OBJECTIVE: We examined whether supplementation during pregnancy with iron and folic acid plus beta-carotene or zinc or both improves the micronutrient status of mothers and infants postpartum. DESIGN: Pregnant women (n = 170) were supplemented daily only during pregnancy with beta-carotene (4.5 mg), zinc (30 mg), or both or placebo plus iron (30 mg) and folic acid (0.4 mg) in a randomized, double-blind, placebo-controlled trial. Micronutrient status was assessed 1 and 6 mo postpartum. RESULTS: Six months postpartum, plasma retinol concentrations were higher in the women who received zinc during pregnancy than in women who did not. Infants born to mothers supplemented with beta-carotene + zinc had higher plasma retinol concentrations, with the frequency of vitamin A deficiency reduced by >30% compared with the other 3 groups. Breast-milk beta-carotene concentrations were higher in all women supplemented with beta-carotene, but breast-milk retinol concentrations were higher only in women who received beta-carotene + zinc. Zinc concentrations did not differ among groups in mothers and infants. CONCLUSIONS: Zinc supplementation during pregnancy improved the vitamin A status of mothers and infants postpartum, which indicates a specific role of zinc in vitamin A metabolism. Addition of both beta-carotene and zinc to iron supplements during pregnancy could be effective in improving the vitamin A status of mothers and infants.  相似文献   

14.
BACKGROUND: More information is needed on the efficacy of carotenoids from plant foods in improving vitamin A status. OBJECTIVE: We aimed to quantify the efficacy of provitamin A-rich vegetables and fruit in improving vitamin A status. DESIGN: Breastfeeding women in 9 rural communes in Vietnam were randomly allocated to 1 of 4 groups: the vegetable group (n = 73), which ingested 5.6 mg beta-carotene/d from green leafy vegetables; the fruit group (n = 69), which ingested 4.8 mg beta-carotene/d from orange or yellow fruit; the retinol-rich group (n = 70), which ingested 610 microg retinol/d from animal foods and 0.6 mg beta-carotene/d; and the control group (n = 68), which ingested 0.4 mg beta-carotene/d. Meals of groups 1, 2, and 4 contained <30 microg retinol/d. Lunch and dinner were provided 6 d/wk for 10 wk. RESULTS: Mean (95% CI) changes in serum retinol concentrations of the vegetable, fruit, retinol-rich, and control groups were 0.09 (0.03, 0.16), 0.13 (0.07, 0.19), 0.25 (0.17, 0.33), and 0.00 (-0.06, 0.06) micromol/L, respectively. Mean (95% CI) changes in breast-milk retinol concentrations were 0.15 (0.04, 0.27), 0.15 (0.02, 0.28), 0.48 (0.32, 0.64), and -0.06 (-0.21, 0.09) micromol/L, respectively. According to these findings, the equivalent of 1 microg retinol would be 12 microg beta-carotene (95% CI: 8, 22 microg) for fruit and 28 microg beta-carotene (17, 84 microg) for green leafy vegetables. Thus, apparent mean vitamin A activity of carotenoids in fruit and in leafy vegetables was 50% (95% CI: 27%, 75%) and 21% (7%, 35%), respectively, of that assumed. CONCLUSION: The bioavailability of carotenoids from vegetables and fruit is less than previously assumed.  相似文献   

15.
The authors examined the associations of maternal smoking in pregnancy with various fetal growth characteristics among 7,098 pregnant women participating in the Generation R Study (2002-2006), a population-based prospective cohort study of pregnant women and their children in Rotterdam, the Netherlands. Maternal smoking was assessed by questionnaires administered in early, mid-, and late pregnancy. Fetal growth characteristics evaluated included head circumference, abdominal circumference, and femur length measured repeatedly in mid- and late pregnancy. Maternal smoking during pregnancy was associated with reduced growth in head circumference (-0.56 mm/week; 95% confidence interval (CI): -0.73, -0.40), abdominal circumference (-0.58 mm/week; 95% CI: -0.81, -0.34), and femur length (-0.19 mm/week; 95% CI: -0.23, -0.14). This reduced growth resulted in a smaller femur length from midpregnancy (gestational age 18-24 weeks) onwards and smaller head and abdominal circumferences from late pregnancy (gestational age > or =25 weeks) onwards. Analyses using standard deviation scores for the growth characteristics demonstrated the largest effect estimates for femur length. The authors concluded that maternal smoking during pregnancy is associated with reduced growth in fetal head circumference, abdominal circumference, and femur length. The larger effect on femur length suggests that smoking during pregnancy affects primarily peripheral tissues.  相似文献   

16.
Meta-analyses of randomized controlled intervention trials were conducted to assess the effects of vitamin A, iron, and multimicronutrient interventions on the growth of children < 18 y old. A PubMed database search and other methods identified 14 vitamin A, 21 iron, and 5 multimicronutrient intervention studies that met the design criteria. Weighted mean effect sizes and CI were calculated using a random effects model for changes in height and weight. Tests for homogeneity and stratified analyses by predefined characteristics were conducted. Vitamin A interventions had no significant effect on growth; effect sizes were 0.08 (95% CI: -0.20, 0.36) for height and -0.01 (95% CI: -0.24, 0.22) for weight. Iron interventions also had no significant effect on child growth. Overall effect sizes were 0.09 (95% CI: -0.07, 0.24) for height and 0.13 (95% CI: -0.05, 0.30) for weight. The results were similar across categories of age, duration of intervention, mode and dosage of intervention, and baseline anthropometric status. Iron interventions did result in a significant increase in hemoglobin (Hb) concentrations with an effect size of 1.49 (95% CI: 0.46, 2.51). Multimicronutrient interventions had a positive effect on child growth; the effect sizes were 0.28 (95% CI: 0.16, 0.41) for height and 0.28 (95% CI: -0.07, 0.63) for weight. Interventions limited to only vitamin A or iron did not improve child growth. Multimicronutrient interventions, on the other hand, improved linear and possibly ponderal growth in children.  相似文献   

17.
This study aimed to quantify the association between adequacy of prenatal care and prevalence of folic acid, iron, and multivitamin intake during pregnancy. Data were obtained on socio-demographics, prenatal care, pregnancy complications, and use of vitamin/mineral supplements for 836 women, using a postpartum interview. Associations with the use of vitamin/mineral supplements were quantified with risk ratios (RR), computed by generalized binomial regression. A high proportion of women reported the use of folic acid (81.9%), iron (55.4%), and multivitamins (76.2%) as supplements during pregnancy. Use of supplements was independently associated with adequacy of prenatal care (adequate vs. inadequate: folic acid, RR = 2.28; 95%CI: 1.58-3.29; iron, RR = 1.99; 95%CI: 1.57-2.52, multivitamins, RR = 1.97; 95%CI: 1.54-2.51). Higher schooling was also associated with increased use of folic acid (RR = 1.42; 95%CI: 1.18-1.70), but not multivitamins (RR = 0.87; 95%CI: 0.77-0.98). Use of folic acid was less prevalent in single women (RR = 0.67; 95%CI: 0.48-0.95) and during unplanned pregnancies (RR = 0.81; 95%CI: 0.71-0.92). Adequacy of prenatal care is a major determinant of vitamin/mineral intake during pregnancy.  相似文献   

18.
BACKGROUND: In recent prospective studies, higher homocysteine concentrations were shown to be a risk factor for osteoporotic fractures in older persons. Supplements containing folate and vitamins B-12 and B-6 lower homocysteine concentrations. OBJECTIVE: The objective of the study was to determine in healthy older persons whether lowering homocysteine with B vitamins affects plasma biomarkers of bone turnover. DESIGN: Healthy older persons (n = 276; aged >or=65 y) were randomly assigned to receive either a daily supplement containing folate (1 mg), vitamin B-12 (500 microg), and vitamin B-6 (10 mg) or a placebo for 2 y. Of these participants, we selected 135 with baseline homocysteine concentrations >15.0 micromol/L, and we measured serum bone-specific alkaline phosphatase, a marker of bone formation, and bone-derived collagen fragments, a marker of bone resorption, at baseline and 2 y later. RESULTS: At 2 y, plasma homocysteine concentrations were 5.2 mumol/L (95% CI: 3.9, 6.6 micromol/L; P < 0.001) lower in the vitamin than in the placebo group. No significant differences were found in either serum bone-specific alkaline phosphatase (-0.3 microg/L; 95% CI: -2.8, 2.1 microg/L; P = 0.79) or bone-derived collagen fragments (-0.0 microg/L; 95% CI: -0.1, 0.1 microg/L; P = 0.76) between the vitamin and placebo groups, respectively, with 2 y of supplementation. CONCLUSION: Supplementation with folate and vitamins B-6 and B-12 lowered plasma homocysteine but had no beneficial effect on bone turnover at the end of 2 y, as assessed by biomarkers of bone formation and resorption.  相似文献   

19.
Variation in the relationship between plasma retinol-binding protein (RBP) and retinol (ROH) has implications for vitamin A (VA) status assessment using RBP. Our objectives were to identify factors affecting the RBP:ROH relationship and to derive and evaluate population-specific RBP cutoffs for VA deficiency (VAD) in Cameroon. Plasma RBP, C-reactive protein (CRP), α1-acid-glycoprotein (AGP), and ROH concentrations were compared in a subsample of women 15-49 y (n = 121) and children 12-59 mo (n = 123) included in a national survey conducted in 2009. Plasma RBP and ROH were highly correlated (r = 0.94 for women; r = 0.96 for children; P < 0.001). Pregnancy and lactation altered the RBP:ROH relationship in women, but obesity, elevated CRP and AGP, age, and VA status did not. Among children, age altered the RBP:ROH relationship, but sex, stunting, VA status, and elevated CRP and AGP did not. Cutoffs for VAD derived using regression analysis were <1.17 μmol RBP/L for women (corresponding to <1.05 μmol ROH/L) and <0.83 μmol RBP/L for children (corresponding to <0.70 μmol ROH/L). The sensitivity and specificity of derived cutoffs were 81.8 and 93.0% for women and 94.7 and 88.9% for children, respectively. The infection-adjusted prevalence of low VA status (<1.17 μmol RBP/L) was 21.9% (95% CI = 18.7-25.0%) among women. Among children, the infection-adjusted prevalence of VAD (<0.83 μmol RBP/L) was 35.0% (95% CI = 31.1-39.0%). In conclusion, VAD remains a public health problem in Cameroon. The RBP:ROH relationship should be considered in surveys using RBP to assess VA status, and use of population-specific cutoffs may be advisable.  相似文献   

20.
Little is known about the long-term effects of DHA intake during pregnancy. Offspring of primagravid Mexican women who received 400 mg/d DHA from wk 20 of gestation through delivery were heavier and had larger head circumferences at birth than children whose mothers received placebo; no effect was observed in offspring of multigravidae. We have followed these children (n = 739; 76% of the birth cohort), measuring length, weight, and head circumference at 1, 3, 6, 9, 12, and 18 mo. At 18 mo, intent-to-treat differences between placebo and DHA, adjusted for maternal height and child sex and age at measurement, were: length, -0.21 cm (95% CI = -0.58, 0.15); weight, -0.03 kg (95% CI =-0.19, 0.13); and head circumference, 0.02 cm (95% CI = -0.18, 0.21) (all P > 0.05). There was heterogeneity of associations by maternal gravidity for weight (P < 0.08), length (P < 0.02), and head circumference (P < 0.05). Among offspring of primagravid women, length at 18 mo was increased by 0.72 cm (95% CI = 0.11, 1.33) following DHA supplementation, representing 0.26 length-for-age Z-score units; among offspring of multigravidae, the estimate was -0.13 cm (95% CI = -0.59, 0.32) (P > 0.5). Maternal DHA supplementation during the second half of gestation may enhance growth through 18 mo of children born to primagravid women.  相似文献   

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