Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vitamin A levels in plasma and other nutritional indices were measured during pregnancy for 449 women enrolled in a multicenter cohort study of mother-to-infant transmission of human immunodeficiency virus type 1 (HIV-1). During the third trimester, 29.6% of the women had low (20 to <30 microg/dL) and 11.1% had very low (<20 microg/dL) vitamin A levels. Vitamin A and body mass index, serum albumin levels, and hemoglobin levels were weakly correlated. After adjustment for other covariates, women with low and very low vitamin A levels before the third trimester were more likely to deliver infants with low birth weight (<2500 g) than were those with higher levels (odds ratio [OR], 4.58; 95% confidence interval [CI], 1.57-13.4; and OR, 6.99; 95% CI, 1.09-45.0, respectively). However, there was no statistically significant association between vitamin A level and mother-to-infant transmission of HIV-1. Anemia and low body mass index before the third trimester were associated with an increased risk of transmission in univariate analyses but not in multivariate analyses.
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PMID:Vitamin A deficiency and other nutritional indices during pregnancy in human immunodeficiency virus infection: prevalence, clinical correlates, and outcome. Women and Infants Transmission Study Group. 1047 37

A National fortification program instituted in Venezuela in 1993 reduced iron deficiency and anemia by half in only 1 y. The fortification mixture contained ferrous fumarate, vitamin A and other vitamins. We conducted experiments to characterize ferrous fumarate uptake by Caco-2 cells. Increasing amounts of ferrous fumarate, vitamin A, phytate, tannic acid and beta-carotene were added to incubation mixtures using a range of concentrations that included the molar ratios used in the Venezuelan fortification program. Cells were incubated for 1 h at 37 degrees C with 37 kBq (59)Fe and the compound to be evaluated. They were then rinsed, trypsinized and counted to measure uptake. Effects of ascorbic acid, days in culture and use of flasks or inserts were also evaluated. Optimal conditions for uptake experiments were pH 5.5, in the presence of ascorbic acid and at 16 d in culture. Use of flasks or inserts did not affect uptake. Vitamin A did not significantly increase iron uptake under the experimental conditions employed. However, beta-carotene (6 micromol/L) significantly increased iron uptake compared to no beta-carotene addition (114.9 +/- 6.3 and 47.2 +/- 5.9 pmol/mg cell protein, respectively). Moreover, in the presence of phytates or tannic acid, beta-carotene generally overcame the inhibitory effects of both compounds depending on their concentrations. We conclude that beta-carotene improves iron uptake and overcomes the inhibition by potent inhibitors of iron absorption. These experiments also validated the usefulness of Caco-2 cell model system to evaluate iron metabolism.
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PMID:Beta-carotene and inhibitors of iron absorption modify iron uptake by Caco-2 cells. 1061 57

Vitamin A deficiency produces anemia and altered iron status. In this study with rats we tested two hypotheses regarding vitamin A deficiency: (1) that it impairs erythropoiesis, leading to an increased red cell turnover, and (2) that it inhibits the glycosylation of transferrin. Erythropoietic activity was assessed indirectly by determining the myeloid:erythroid ratio in bone marrow smears, the number of erythroid colonies in the red pulp of spleen, the blood reticulocyte index, and zinc protoporphyrin and plasma transferrin receptor concentrations. Transferrin glycosylation was assessed by measuring the sialic acid content of transferrin. The effects of vitamin A deficiency were compared with those of iron deficiency. Iron deficiency produced anemia and low iron levels in organs. Vitamin A deficiency produced low levels of plasma and hepatic retinol, and it induced decreased plasma total iron-binding capacity and raised iron levels in tibia and spleen. Short- but not long-term iron deficiency reduced the number of erythroid colonies in spleen; vitamin A deficiency had no influence. Neither iron nor vitamin A deficiency influenced the myeloid:erythroid ratio in bone marrow smears and the blood reticulocyte production. Plasma transferrin receptor and erythrocyte zinc protoporphyrin concentrations were not affected by vitamin A deficiency but increased with iron deficiency. Vitamin A deficiency did not stimulate erythrocyte breakdown, as indicated by unaltered plasma lactate dehydrogenase activity and reduced plasma total bilirubin levels. Both vitamin A and iron deficiencies raised the proportion of multiple sialylated transferrins in plasma. Thus, we have not found evidence that vitamin A deficiency affects erythropoiesis and erythrocyte turnover. The iron accumulation in spleen and bone marrow may be related to reduced iron transport due to inhibition of transferrin synthesis rather than inhibition of transferrin sialylation.
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PMID:Indicators of erythrocyte formation and degradation in rats with either vitamin A or iron deficiency. 1082 45

The objective of this cross-sectional study was to identify risk factors for anemia among human immunodeficiency virus (HIV)-positive pregnant women in Dar es Salaam, Tanzania. Baseline data from 1064 women enrolled in a clinical trial on the effect of vitamin supplementation in HIV infection were examined to identify potential determinants of anemia. The mean hemoglobin (Hb) level was 94 g/L, and the prevalence of severe anemia (Hb < 85 g/L) was 28%; 83% of the women had Hb < 110 g/L. Iron deficiency and infectious disease appeared to be the predominant causes of anemia. Significant independent associations with severe anemia were observed for women with body mass index (BMI) < 19 kg/m(2) compared with women with BMI > 24 kg/m(2) [odds ratio (OR) 3.13, 95% confidence interval (CI): 1. 37-7.14); malaria parasite densities > 1000/mm(3) (OR 2.70, CI: 1. 58-4.61) compared with women with no parasites; eating soil during early pregnancy (OR 2.47, CI: 1.66-3.69); CD4+ cell count < 200/microL compared with CD4+ count > 500/microL (OR 2.70, CI: 1. 42-5.12); and serum retinol levels < 70 micromol/L (OR 2.45, CI: 1. 44-4.17) compared with women with retinol levels > 1.05 micromol/L. The most significant risk factors associated with severe anemia in this population are preventable. Public health recommendations include increasing the effectiveness of iron supplementation and malaria management during pregnancy, and providing health education messages that increase awareness of the potentially adverse nutritional consequences of eating soil during pregnancy.
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PMID:Nutritional factors and infectious disease contribute to anemia among pregnant women with human immunodeficiency virus in Tanzania. 1091 7

Anemia and iron deficiency during pregnancy are prevalent in developing countries, but their causes are not always known. We assessed the prevalence and severity of anemia and iron deficiency and their association with helminths, malaria and vitamin A deficiency in a community-based sample of 336 pregnant women in the plains of Nepal. Hemoglobin, erythrocyte protoporphyrin (EP) and serum ferritin were assessed in venous blood samples. Overall, 72.6% of women were anemic (hemoglobin < 110 g/L), 19.9% had moderate to severe anemia (hemoglobin < 90 g/L) and 80.6% had iron deficiency (EP > 70 micromol/mol heme or serum ferritin < 10 microg/L). Eighty-eight percent of cases of anemia were associated with iron deficiency. More than half of the women (54.2%) had a low serum retinol concentration (<1.05 micromol/L), 74.2% were infected with hookworms and 19.8% had Plasmodium vivax malaria parasitemia. Hemoglobin, EP and serum ferritin concentrations were significantly worse and the prevalence of anemia, elevated EP and low serum ferritin was increased with increasing intensity of hookworm infection. Hookworm infection intensity was the strongest predictor of iron status, especially of depleted iron stores. Low serum retinol was most strongly associated with mild anemia, whereas P. vivax malaria and hookworm infection intensity were stronger predictors of moderate to severe anemia. These findings reinforce the need for programs to consider reducing the prevalence of hookworm, malaria infection and vitamin A deficiency where indicated, in addition to providing iron supplements to effectively control anemia.
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PMID:Hookworms, malaria and vitamin A deficiency contribute to anemia and iron deficiency among pregnant women in the plains of Nepal. 1101 85

We conducted a randomized controlled trial of the effects of dietary supplements on anemia, weight and height in 136 anemic school children from a low socioeconomic background in Bagamoyo District schools in Tanzania. The aim of the current study was to investigate the impact of dietary supplements on anemia and anthropometric indices of anemic school children. The supplements were vitamin A alone, iron and vitamin A, iron alone or placebo, administered in a double-blinded design for 3 mo. All supplements were provided with local corn meals. Hemoglobin concentration, body weight and height were measured at baseline and at follow-up after supplementation. Vitamin A supplementation increased the mean hemoglobin concentration by 13.5 g/L compared with 3.5 g/L for placebo [P < 0.0001, 95% confidence interval (CI) 6.19-13.57), the mean body weight by 0.6 kg compared with 0.2 kg for placebo (P < 0.0001, 95% CI 0.19-0.65) and the mean height by 0.4 cm compared with 0.1 cm for placebo (P = 0.0009, 95% CI 0.08-0.42). However, the group of children who received combined vitamin A and iron supplementation had the greatest improvements in all indicators compared with placebo (18.5 g/L, P < 0.0001, 95% CI 14.81-22.23; 0.7 kg, P < 0. 0001, 95% CI 0.43-0.88 and 0.4 cm, P < 0.0001, 95% CI 0.22-0.56 for hemoglobin, weight and height, respectively). It is likely that vitamin A supplementation may have a useful role in combating the problems of vitamin A deficiency and anemia, as well as in improving children's growth, in developing countries.
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PMID:Supplemental vitamin A improves anemia and growth in anemic school children in Tanzania. 1105 8

A community-based cross-sectional study was undertaken to measure anthropometric indices, micronutrient status and prevalence of parasite infections in 579 rural South African primary school children. Eleven schools were selected randomly from a Magisterial District in southern KwaZulu-Natal (KZN). In each school, all pupils aged between 8 and 10 years were selected. The following outcome measures were obtained: anthropometric--height for age, weight for age and body mass index; micronutrient status--anaemia, serum ferritin and vitamin A; and prevalence of parasite infections--Ascaris lumbricoides, Trichuris trichiura and Schistosoma haematobium. The observed prevalences were: stunting 7.3%, underweight for age 0.7%, and obesity 3.1%; anaemia 16.5% (Hb < 12 g/dl), vitamin A deficiency 34.7% (serum retinol < 20 micrograms/dl) and 28.1% with reduced serum ferritin (< 12 ng/ml); Trichuris trichiura 53.9%, Ascaris lumbricoides 27.3% and Schistosoma haematobium 24.5%. We conclude that micronutrient deficiency, parasitic infestations and stunting remain significant problems among school-aged children in South Africa. Micronutrient supplementation and de-worming provide opportunities for school-based health promotion and primary health care interventions, and might produce significant health and educational benefits.
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PMID:A health and nutritional profile of rural school children in KwaZulu-Natal, South Africa. 1128 48

The associations of hemoglobin, hematocrit, and packed cell volume with socioeconomic factors, malaria, human immunodeficiency virus (HIV) infection, and nutritional status were examined among 687 children admitted to hospital with pneumonia participating in a double blind, placebo-controlled trial of vitamin A supplementation. Children were randomized to receive 2 doses of vitamin A (200,000 IU) or placebo at baseline, and additional doses at 4 and 8 months after discharge from hospital. Hemoglobin levels were measured at enrollment and, on a subset of 161 children, during follow-up. At baseline, hemoglobin concentration was positively associated with the number of possessions in the household, maternal level of education and quality of water supply, and inversely related to malaria infection after controlling for potential confounding variables. Children infected with HIV experienced a significant fall in mean hemoglobin levels over time. The risk of developing severe anemia (< 7 g/dL) during follow-up was lower for children who were breastfed for longer than 18 months as compared to those with less than 6 months of breastfeeding (adjusted prevalence ratio = 0.14, 95% confidence interval [CI] = 0.02, 0.93; P = 0.04), and higher for children over two years of age as compared to 6 to 11 months-old infants (adjusted prevalence ratio = 8.11, 95% CI = 1.2, 55.8; P = 0.03). Children with repeated diagnoses of malaria had 4.1 times the risk of developing severe anemia than did children without the diagnosis (95% CI = 1.3, 13.5; P = 0.02). Vitamin A supplements were associated with an overall nonsignificant reduction of 14% in the risk of developing severe anemia (adjusted prevalence ratio = 0.86, 95% CI = 0.37, 1.99; P = 0.73). We conclude that malaria, HIV infection, low socioeconomic status, and short duration of breastfeeding are strong and independent determinants of adverse hematologic profiles in this population.
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PMID:Vitamin A supplementation and other predictors of anemia among children from Dar Es Salaam, Tanzania. 1128 70

Nutritional status directly affects immune competence; therefore, dietary supplements can be beneficial. Vitamin A, a fat-soluble nutrient obtained exogenously from animal protein or synthesized endogenously from carotenoids, is important in vision, epithelial tissue maintenance, reproduction, and growth. It is also an antioxidant, and can interfere with HIV-related oxidative destruction. Vitamin C, a water-soluble antioxidant important in hydroxylation reactions and required by erythrocytes for retrieving stored iron, can suppress HIV in vitro. However, this requires long-term administration, and its effect ceases upon termination of treatment. Vitamin E, fat-soluble tocopherols, can be found in plants, vegetable oils, milk, eggs, fish, meats, and cereals. A potent antioxidant because of its electron-donating ability, vitamin E reduces HIV replication. Deficiency reduces inhibition of tumor necrosis factor alpha (TNF-a) and protein kinase C, therefore limiting immunocompetence. Additionally, damaging side effects of AZT, normally reversed or minimized by vitamin E, may induce low leukocyte counts and anemia. Vitamin E acts synergistically with selenium, another antioxidant, to block the rate of lipid peroxidation. Its administration may reduce diarrhea, cramping, and weight loss, and may improve epithelial conditions and reduce the frequency of illness. N-acetylcysteine (NAC), a sulfur-containing amino acid, inhibits HIV replication by raising serum glutathione levels through inhibition of TNF-a. Finally, HIV-infected patients should consider gluten-free diets during times of acute gastric distress.
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PMID:Nutrition and HIV. 1136 99

Vitamin A, a fat-soluble, heat-stable nutrient (retinol) derived from animal sources and certain fruits and vegetables, forms the basic component of retinal pigments and plays a vital role in optimal health, growth, and development. Vitamin A deficiency (VAD) (serum retinol < or = 20 microg/dL [< or = 0.7 micromol/L] for subclinical VAD) can substantially increase the risk for childhood mortality from infectious and noninfectious causes. VAD impairs the mobilization and transport of iron and is usually associated with anemia and reduced growth. VAD is a major public health problem in parts of Africa, Asia, Latin America, and the Western Pacific. In Chuuk and Pohnpei, two of the four Federated States of Micronesia (FSM) (2000 population: 107,008), nutrition surveys during the early 1990s documented VAD prevalences among the highest in the world (CDC, unpublished data, 1991; U.S. Public Health Service, unpublished data, 1994). In response to these findings, FSM health authorities, with support of the United Nations Children's Fund (UNICEF), began distributing vitamin A supplements in 1993 and 1998 in Chuuk and Pohnpei, respectively. In November 1999, FSM requested assistance from CDC in VAD assessment surveys of children in Kosrae and Yap, the other two FSM states. This report summarizes levels of serum retinol and prevalence of VAD and other indicators of nutritional status among children aged 24-59 months in Kosrae and Yap. The findings indicated low serum retinol levels and high VAD prevalences but no substantial stunting or wasting. A comprehensive, long-term national strategy is needed in FSM to promote sustained improvement in vitamin A status.
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PMID:Vitamin A deficiency among children--Federated States of Micronesia, 2000. 1143 74


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