RESUMO
Aflatoxins are toxic metabolites found in foods and feeds. When ruminants eat foodstuffs containing aflatoxins B(1) and B(2), these toxins are metabolized and excreted as aflatoxin M(1) and M(2) in milk. The aim was to determine the incidence of these aflatoxins in commercial milk collected from supermarkets in Ribeirão Preto-SP, Brazil, and consisting of 60 ultrahigh temperature (UHT) milk samples and 79 pasteurized milk samples. The milk samples were analysed according to method 986.16 of AOAC International. None of the milk samples analysed were contaminated with aflatoxin M(2), and aflatoxin M(1) was detected in 29 (20.9%) of samples in the range 50-240 ng l(-1). The results show that despite a high occurrence of aflatoxin M(1) in commercial pasteurized and UHT milk sold in Ribeirão Preto in 1999 and 2000, the contamination level of these toxins could not be considered a serious public health problem according to MERCOSUR Technical Regulations. However, levels in 20.9% of the milk samples exceeded the concentration of 50 ng l(-1) permitted by the European Union. Although it is not necessary to continue monitoring the incidence and levels of aflatoxins M(1) and M(2) in milk samples, surveillance could be appropriate.
Assuntos
Aflatoxina M1/análise , Aflatoxinas/análise , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Leite/química , Animais , Brasil , Cromatografia Líquida/métodos , Microbiologia de AlimentosRESUMO
The use of available food rich in provitamin A and retinol as well as fortification of local food are known to result in adequate vitamin A status. In Brazil, several regional foods are known to be good sources of provitamin A such as buriti, several palm oils, mango and others. Improving the consumption of these locally available natural sources of provitamin and vitamin A would cover the needs of the vulnerable population. At the same time fortification of industrialized foods with natural and/or synthetic forms of provitamin A could speed up and fill the gap between requirement and low intake of this vitamin in many parts of the country. This approach has been considered by many as the most effective intervention program to prevent micronutrient deficiencies in developing countries. Our previous studies on the subject have shown that cooking vegetable oil, mainly soybean oil, is a very good alternative vehicle to be fortified and supply vitamin A to the population. Lately we have also enriched the same soybean oil with beta-carotene. Addition of this provitamin A to the oil showed it to be stable when heated at cooking and frying temperatures (retention of 92.4 +/- 6.7% and 65.4 +/- 8.6%, respectively). When rat or human food was prepared with carotene-enriched cooking oil, its bioavailability in experimental animals and absorption in humans were shown to be adequate. An alternative for Brazil, besides adding chemical forms of the vitamin to the cooking oil, would be to mix available carotene-rich palm oil to the soybean oil. There are already regional uses of carotenoid-rich palm oils in the preparation of local dishes in some parts of Brazil and this would facilitate its acceptance by the population. Enrichment of common foods in Brazil, such as soybean oil, with chemical forms of beta-carotene or mixing rich sources of provitamin A can be a good alternative to improve the intake of vitamin A by the Brazilian population.
Assuntos
Carotenoides/metabolismo , Alimentos Formulados , Óleos de Plantas , Óleo de Soja , Vitamina A/biossíntese , Animais , Disponibilidade Biológica , Ingestão de Alimentos , Feminino , Frutas , Temperatura Alta , Humanos , Masculino , Micronutrientes , Óleos de Plantas/química , Ratos , Verduras , Vitamina A/sangue , Vitamina A/uso terapêutico , Deficiência de Vitamina A/prevenção & controle , beta Caroteno/sangue , beta Caroteno/farmacocinéticaRESUMO
Vitamin A deficiency is one of the major nutritional problems in the world, most common in developing countries. Food fortification is a recognised approach to supply vitamins and minerals to needed populations. Vegetable cooking oils were previously suggested by us as a carrier for vitamin A fortification. Fortification of cooking oil with beta-carotene could also be a strategy to prevent vitamin A deficiency. The objective of this article is to start studies on the use of cooking soya oil as a vehicle for synthetic carotene, to evaluate its stability to heat treatment, and to test its bioavailability and bioconversion to vitamin A in rats. Batches of carotene-fortified soybean oil were prepared, containing 2, 4 and 8 RE/g of diet. Some of them were heated to test its stability. At 100 degrees C there was no loss of carotene, at higher temperature carotene retention was 65%. The bioavailability and bioconversion of beta-carotene added to soybean oil was measured through feeding nursing rats and their pups method. Weight gain was good and plasma vitamin A increased significantly in all groups. Liver vitamin A values of rats fed diets with fortified soybean oil heated at 100 degrees C was similar to the 4 RE non-heated fortified oil group (0.72 +/- 0.06 and 0.64 +/- 0.08 mumol/g, respectively). Heated at 170 degrees C the liver total vitamin A value was reduced (0.45 +/- 0.04 mumol/g), but kept bioavailable vitamin A equivalent to 2 RE (0.47 +/- 0.09 mumol/g). Bioconversion of beta-carotene to vitamin A was validated by the plasma and liver findings. beta-carotene added to soybean oil showed good stability to heat and its bioconversion to vitamin A was shown in rat assays. beta-carotene mixed well with edible soybean oil and the fortified cooking oil showed potential as a carrier to be used for the prevention of vitamin A deficiency.
Assuntos
Gorduras Insaturadas na Dieta , Alimentos Fortificados , Temperatura Alta , Óleo de Soja , Deficiência de Vitamina A/dietoterapia , beta Caroteno/farmacocinética , Análise de Variância , Animais , Disponibilidade Biológica , Feminino , Fígado/química , Valor Nutritivo , Ratos , Ratos Wistar , Vitamina A/análise , Vitamina A/sangue , beta Caroteno/metabolismoRESUMO
The relation between vitamin A status and the degree of lung airway obstruction was examined in a cross-sectional study of 36 male subjects aged 43-74 y who were assigned to five groups as follows: healthy nonsmokers (n = 7), healthy smokers (n = 7), mild chronic obstructive pulmonary disease (COPD-mild) patients (n = 9), COPD-moderate-severe patients (n = 7), and COPD-moderate-severe patients with exacerbation (+ex; n = 6). Smoking habits, pulmonary function tests, energy-protein status were assessed; serum concentrations of retinyl esters, retinol, retinol binding protein, and transthyretin and relative dose responses were measured. In addition, 12 male smokers aged 45-61 y with mild COPD were randomly assigned to two groups for a longitudinal study: six subjects consumed vitamin A (1000 RE/d; COPD-vitamin A) and six subjects received placebo for 30 d. Lowered serum retinol concentrations were found in the COPD-moderate-severe and COPD-moderate-severe+ex groups. Measurements of vitamin A status in healthy smokers and in COPD-mild patients were not different from those in healthy nonsmokers. The improvement of pulmonary function test results after vitamin A supplementation [mean increase for 1-s forced expiratory volume (FEV1) = 22.9% in the COPD-vitamin A group] may support the assumption of a local (respiratory) vitamin A deficiency in patients with this disease.
Assuntos
Pneumopatias Obstrutivas/sangue , Fumar , Vitamina A/sangue , Adulto , Idoso , Análise de Variância , Carotenoides/sangue , Estudos Transversais , Dieta/normas , Humanos , Absorção Intestinal/fisiologia , Fígado/metabolismo , Estudos Longitudinais , Pulmão/efeitos dos fármacos , Pulmão/fisiologia , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Testes de Função Respiratória , Vitamina A/metabolismo , Vitamina A/farmacologia , Deficiência de Vitamina A/fisiopatologiaRESUMO
The objective of the present study was to assess zinc nutritional status in alcoholic patients with pellagra using plasma, hair, urine and nail zinc levels, as well as the zinc tolerance test. The study was conducted on 81 patients, 73 males and eight females. Zinc parameters were compared with those of 84 individuals with no apparent disease aged 23-45 years. Plasma zinc levels were lower in patients with pellagra than in the controls (P < 0.01). The results of the zinc tolerance test showed that: (1) basal zinc levels were 69.7 +/- 16.8 micrograms/100 ml in pellagrins and 82.3 +/- 34.0 micrograms/100 ml in the controls (P < 0.01); (2) after 1 h the increase in plasma levels was similar in the pellagrin and control groups; (3) during the second hour the increase was more marked in the controls (P < 0.01), and the same was observed during the third and fourth hours (P < 0.05). Urinary zinc excretion (mg/24 h) was higher in pellagrins (P < 0.01). Zinc concentration in hair and toenails did not differ between pellagrins and controls. We conclude that pellagrins present zinc deficiency as demonstrated by plasma and urine zinc levels and by their abnormal response to the zinc tolerance test. We suggest that hair and nail zinc levels should not be used to assess zinc nutritional status in patients with pellagra.
Assuntos
Alcoolismo/complicações , Pelagra/diagnóstico , Zinco/deficiência , Adulto , Alcoolismo/metabolismo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Pelagra/metabolismo , Valores de Referência , Distribuição TecidualRESUMO
The objective of the present paper was to study the interaction of Neomycin and aluminium hydroxide with vitamin A in terms of the effect of these drugs on the bioavailability of vitamin A in the rat. Bioavailability was determined on the basis of the effects of the drugs on growth and on the plasma and hepatic levels of the vitamin. Vitamin A deficient animals were used in assay 1 and normal animals in assay 2. In each assay the animals were divided into 3 groups: one received Neomycin sulfate (0.1% in the diet), the second received aluminium hydroxide (0.05% in the diet) and the third (control) received no drug. Each of these three groups was subdivided into two groups receiving two different concentrations of vitamin A palmitate. The bioavailability of vitamin A was estimated by the parallel line method from the concentration of vitamin A in the diet and in the liver of the animals. No significant differences in growth or plasma retinol levels were observed between the groups of animals studied in assays 1 and 2. Total vitamin A concentration in the liver of the animals which received Neomycin was lower (p < 0.05) than that observed in the controls. Neomycin reduced the bioavailability of vitamin A by 13.9% (maximum, 18.1% and minimum, 9.6%) in assay 1 and by 13.5% (maximum, 17.7% and minimum, 9.3%) in assay 2. Aluminium hydroxide at the level tested did not affect the bioavailability of vitamin A.
Assuntos
Hidróxido de Alumínio/farmacologia , Neomicina/farmacologia , Vitamina A/metabolismo , Animais , Disponibilidade Biológica , Interações Medicamentosas , Feminino , Cinética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar , Vitamina A/sangue , Deficiência de Vitamina A/metabolismo , Aumento de PesoRESUMO
Hypovitaminosis A is a widespread problem, especially among preschool children in many parts of the world. According to the World Health Organization (WHO) estimates, about 100,000 children become blind every year, and many are dying due to vitamin A deficiency while millions of others are suffering from other consequences of vitamin A deficiency such as growth retardation and increased susceptibility to infection. It is, therefore, very important that not only the severe cases of hypovitaminosis A be diagnosed for immediate treatment, but also the marginal cases of vitamin A deficiency in vulnerable populations be diagnosed as early as possible so that appropriate preventive measures be implemented. Available methods for the diagnosis of vitamin A deficiency can be classified into four categories: clinical, biochemical, functional, and dietary. Clinical diagnosis is based on examining ocular and extraocular signs of hypovitaminosis A, and is only useful for the detection of severe cases. Biochemical methods are based on the plasma concentrations of retinol and retinol-binding protein (RBP), and liver reserve of vitamin A whenever possible. Two other commonly used diagnostic tests are: functional testing for nightblindness using dark adaptation time, and pathological testing for ocular signs of conjunctival xerosis, with or without the use of Rose Bengal or lissamine green dye. Dietary method for the diagnosis of vitamin A deficiency is based on the estimation of dietary intake of vitamin A and carotenoids. In addition, there are newer methods such as isotope dilution and relative dose response (RDR) techniques which have been recently proposed for the diagnosis of vitamin A deficiency. RDR appears to be a reliable and sensitive indicator of marginal vitamin A. However, the most desirable approach to diagnosis may be one based on multiple indicators for the accurate assessment of vitamin A status in the community. The purpose of this paper is to draw attention to the problems of diagnosis, to recent advances and to our Brazilian experience in this important area of vitamin A research with significant global implications.
Assuntos
Deficiência de Vitamina A/diagnóstico , Pré-Escolar , Túnica Conjuntiva/patologia , Adaptação à Escuridão , Humanos , Fígado/metabolismo , Estado Nutricional , Técnica de Diluição de Radioisótopos , Vitamina A/análise , Vitamina A/sangue , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/metabolismoRESUMO
La hipovitaminosis A es un problema que se presenta en gran escala en el mundo entero, especialmente entre los niños de edad preescolar. De acuerdo a predicciones de la Organización Mundial de la Salud (OMS), alrededor de 100,000 niños pierden la vista anualmente mientras que un número considerable muere debido a deficiencia de vitamina A, y millones sufren serias consecuencias relacionadas con la deficiencia de vitamina A, tales como retardo en crecimiento y cresciente susceptibilidad a las infecciones. Consecuentemente, no sólo es importante que los casos de deficiencia severa de vitamina A sean diagnosticados, sino también los casos marginales. Sobre todo, es crítico que la población susceptible sea diagnosticada lo antes posible, a fin de aplicar las medidas de prevención del caso. Los métodos dispnibles para diagnosticar la deficiencia de vitamina A pueden ser clasificados en cuatro categorias: clínico, bioquímico, funcional y dietético. El diagnóstico clínico se basa en el examen ocular y extraocular para determinar los síntomas de hipovitaminosis A, pero sólo se utiliza para detectar los casos severos. Otras dos pruebas de diagnóstico usadas comúmente son: el test funcional de ceguera nocturna, y las pruebas patológicas, utilizando no "Rosa de Bengala" o "dissaminegreen dye". Los métodos dietéticos para diagnosticar la deficiencia de vitamina A están fundados en la estimación de absorbancia de vitamina A y carotenoides. Además, existen otros métodos tales como dilución isotópica y reacción a dosis relativa (RDR), técnicas éstas que han sido recientemente propuestas para diagnosticar la deficiencia de dicha vitamina. La RDR parece ser de un indicador sensitivo de vitamina A entre grupos sin signos clínicos de hipovitaminosis A. No obstante, el mejor enfoque puede ser el basado en indicadores múltiples para el asesoramiento acertado de la función de vitamina A en la comunidad. El objetivo del trabajo que nos ocupa es llamar la atención a los problemas de diagnóstico, a los recientes adelantos, y a nuestra experiencia en Brasil en este importante campo de investigación de la vitamina A, investigación de implicaciones globales significativas
Assuntos
Humanos , Deficiência de Vitamina A/diagnóstico , Túnica Conjuntiva/citologia , Técnicas Citológicas , Adaptação à Escuridão , Epitélio/citologia , Fígado/metabolismo , Estado Nutricional , Técnica de Diluição de Radioisótopos , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/metabolismo , Vitamina A/análise , Vitamina A/sangueRESUMO
The main objective of the present study was to estimate plasma zinc concentration in children belonging to low-income families residing in three different neighborhoods on the outskirts of Ribeirão Preto, SP, Brazil, and to determine a possible correlation of this parameter with several anthropometric measurements. Plasma zinc levels were lower than 70 micrograms% in 13% of the children studied. Weight for age, height for age and weight/height ratio were below 90% of the 50th percentile of National Center for Health Statistics (NCHS) in 42.9%, 6.3% and 9.5% of children, respectively. Tricipital fold, arm circumference and muscle circumference were also below 90% of the 50th percentile in 65.8%, 11.0% and 7.3% of the children, respectively. No correlation was observed between plasma zinc levels and the anthropometric parameters studied.
Assuntos
Antropometria , Zinco/sangue , Brasil , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Fatores Socioeconômicos , População UrbanaRESUMO
The objective of this study was to evaluate two of several methods presently available for assessing vitamin A status of marginally malnourished preschool children of socioeconomically deprived families in Southern Brazil. The rose bengal staining test and rapid dark-adaptation test were evaluated by comparing their results with conventional methods that require estimation of dietary intake of vitamin A equivalents and determination of plasma levels of retinol before and after an oral supplementation of 200 000 IU vitamin A. Results indicate that neither test evaluated is useful by itself. There was no significant correlation between the results of the rose bengal staining test and the plasma levels of retinol. Also, no significant correlation was observed between the rapid dark-adaptation time and the vitamin A status of the preschool children as determined by plasma-retinol levels before and after vitamin A supplementation.
Assuntos
Adaptação à Escuridão , Inquéritos Nutricionais/métodos , Rosa Bengala , Deficiência de Vitamina A/prevenção & controle , Brasil , Pré-Escolar , Dieta , Estudos de Avaliação como Assunto , Humanos , Vitamina A/sangue , Vitamina A/uso terapêuticoRESUMO
A comprehensive survey was carried out to assess the vitamin A status of preschool children of poor migrant families in the periurban population of Ribeirao Preto, a typical agricultural town in the sugarcane and coffee region of the State of Sao Paulo in Southern Brazil. The intake of vitamin A and carotenoids from the rice and bean based diet of these children is considered low and appears to influence blood concentrations and liver reserves of this vitamin. With respect to plasma vitamin A, 1.8% of the children had a deficient level (less than 10 micrograms%), whereas 48.8% of the children had a low level (less than 20 micrograms%). Most children with inadequate plasma vitamin A (less than 20 micrograms%) responded positively to a massive dose of 200,000 IU vitamin A, suggesting that these children may be at risk of having low liver stores of vitamin A. Rose Bengal staining test and rapid dark adaptation time did not indicate definite signs of conjunctival xerosis and night blindness among these children. No ocular evidence of hypovitaminosis A was found in the children studied, but marginal or inadequate vitamin A status appears to be a common public health problem among young children in this region of Brazil.