Non-alcoholic fatty liver disease in overweight children and its relationship with retinol serum levels.

OBJECTIVES: To evaluate the frequency of non-alcoholic fatty liver disease, the retinol serum levels, lipid profile, and insulin resistance in overweight/obese children. To relate these biochemical variables with the risk of this disease in the population studied. METHODS: The study was cross-sectional and prospective, with 46 overweight/obese school children (28 female, 18 male; mean age 8.6 years). The control group consisted of 45 children, paired by age and gender. Hepatic steatosis, evaluated by ultrasound, was classified as normal, mild, moderate, or severe. Also evaluated were serum retinol levels; thiobarbituric acid reactive substances; lipid profile; and fasting glucose and serum insulin levels, used for the calculation of the Homeostasis Model Assessment. RESULTS: Hepatic ultrasound alterations were found in 56.5% and 48,9% of the overweight/obese and control group children, respectively. Presence of obesity was associated with high levels of triglycerides (OR = 4.6; P = 0.002). In the studied children, the risk of steatosis was related to a trend to a higher percentage of retinol inadequacy (OR = 2.8; p = 0.051); there was no association with thiobarbituric acid reactive substances, lipid profile, or insulin resistance. CONCLUSIONS: The high frequency of non-alcoholic fatty liver disease in both groups, evaluated by hepatic ultrasound, in low-socioeconomic level children, independent of nutritional condition and without significant association with insulin resistance, emphasizes that especially in developing countries, other risk factors such as micronutrient deficiencies (e.g. vitamin A) are involved.

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.

Vitamin A metabolic aspects and alcoholic liver disease

The liver is a strategic organ in the metabolism of macro and micronutrients; when its functioning is compromised, it may cause some change in the nutritional status of vitamin A. The purpose of this article is to review scientific evidence in literature on the liver metabolism of vitamin A, the role of ethanol and retinol interactions on hepatic morphology, besides the alterations in the metabolism of this vitamin in alcoholic liver disease. Data were collected from Medline database. The liver is the main organ responsible for the storage, metabolism and distribution of vitamin A to peripheral tissues. This organ uses retinol for its normal functioning such as cell proliferation and differentiation. This way, vitamin A deficiency seems to alter liver morphology. Patients with alcoholic liver disease have been found to have low hepatic levels of retinol in all stages of their disease. In alcoholic liver disease, vitamin A deficiency may result from decreased ingestion or absorption, reduction in retinoic acid synthesis or increased degradation. Long-term alcohol intake results in reduced levels of retinoic acid, which may promote the development of liver tumor. So, in chronic alcoholic subjects, vitamin A status needs to be closely monitored to avoid its deficiency and clinical effects, however its supplementation must be done with caution since the usual dose may be toxic for those who consume ethanol.

O fígado é um órgão estratégico no metabolismo de macro e de micronutrientes e, portanto, é de esperar que o comprometimento de sua função seja acompanhado de alterações no estado nutricional de vitamina A. O objetivo deste artigo é revisar na literatura evidências científicas sobre o metabolismo hepático da vitamina A, o efeito das interações entre a vitamina A e o etanol sobre a morfologia hepática, além das alterações do metabolismo dessa vitamina na doença hepática alcoólica. Os dados foram selecionados na base de dados Medline no período de 1979 a 2005. O fígado é o principal órgão responsável pelo armazenamento, metabolismo e distribuição da vitamina A para os tecidos periféricos. Esse órgão utiliza retinol para seu funcionamento normal como proliferação e diferenciação celular. Dessa forma, a deficiência dessa vitamina parece alterar a morfologia hepática. Baixos níveis de retinol hepático têm sido encontrados em todos os estágios da doença hepática alcoólica. A deficiência de vitamina A na doença hepática alcoólica pode resultar da diminuição da sua ingestão ou absorção, na redução da síntese de ácido retinóico ou na diminuição da sua degradação. A ingestão crônica de álcool resulta em níveis reduzidos de ácido retinóico, o que favorece a formação de tumor hepático. Logo, em etilistas crônicos o estado nutricional de vitamina A deve ser monitorado, para evitar sua deficiência e seus sintomas clínicos, embora a suplementação deva ser feita com cautela, pois doses comumente usadas podem ser tóxicas para aqueles que consomem etanol.

[Association between maternal and newborn vitamin A status and economic stratum in Rio de Janeiro, Brazil]. / Associação entre deficiência de vitamina A e situação sociodemográfica de mães e recém-nascidos.

BACKGROUND: Retinol was determined spectrophotometrically in the blood of 291 mothers at delivery and in the umbilical cord of the newborn. The mothers came from different socioeconomic strata in Rio de Janeiro. METHODS: Levels of retinol were determined using spectrophotometry (Bessey et al). RESULTS: The circulation levels of retinol were low (below 1.05 micromol/L) in 22.0% of the mothers and in 54.2% of the newborn. A close association was found between low levels in the mothers' serum and those in the children's umbilical cord (p <0.0001). There was no association between maternal vitamin A deficiency (DVA) and socioeconomic stratum, family income or level of education. CONCLUSIONS: DVA is a distressing health problem among mothers and newborns and its diagnosis must be included in antenatal care. This reinforces the concept that intervention programs must emphasize changes in feeding practices and focus on the most vulnerable groups, of which pregnant women warrant special attention, regardless of socioeconomic stratum.

Associação entre deficiência de vitamina A e situação sociodemográfica de mães e recém-nascidos / Association between maternal and newborn vitamin A status and economic stratum in Rio de Janeiro, Brazil

OBJETIVO: Investigou-se a associação entre deficiência de vitamina A (DVA) e condições sociodemográficas em 291 puérperas de diferentes estratos socioeconômicos e seus respectivos recém-nascidos (RN), atendidos em uma maternidade pública do município do Rio de Janeiro, Brasil. MÉTODOS: Os níveis séricos de retinol materno e no sangue de cordão umbilical foram determinados segundo o método Bessey et al. modificado. RESULTADOS: As prevalências de DVA (retinol sérico <1,05 æmol/L) nas puérperas e RN foram de 22 por cento e 54,2 por cento, respectivamente. A DVA materna apresentou-se fortemente associada com a DVA nos RN (p<0,0001). A DVA materna não apresentou associação estatisticamente significativa com as variáveis sociodemográficas - escolaridade materna e renda familiar per capita. Tal achado leva a pensar que mesmo em populações nas quais a DVA subclínica seja a forma mais prevalente, o concepto também tem risco aumentado de nascer deficiente. CONCLUSÃO: A carência em questão é um problema significativo entre as puérperas e seus RN e a sua investigação deve ser incorporada às rotinas de assistência pré-natal. Modificação das práticas e da qualidade da dieta como estratégias de combate à DVA, dirigidas aos grupos populacionais vulneráveis, devem dedicar especial atenção às gestantes, independentemente do nível sociodemográfico.

Serum retinol and total carotene concentrations in obese pre-school children.

BACKGROUND: Obesity among pre-school children and its repercussions on adult life are growing problems, but there has been little research focusing on its relationship with the deficiency of serum retinol and carotenoids in our region. MATERIAL/METHODS: In a case-control study, a group of 46 preschool children, were matched by sex and age (23 obese and 23 non-obese subjects; average age 5.74 and 5.76 years, respectively). Serum retinol and carotenoid levels were evaluated according to Underwood and Sauberlich. Other aspects evaluated included nutritional status using the weight/height z-score (Obesity ZWH > or = 2), serum levels of triglicerides (TG), total cholesterol (TC) and the VLDL-c, HDL-c, and LDL-c fractions, classified according to Kwiterovich. RESULTS: Serum retinol insufficiency was 18.2% vs. 6.7% (p=0.38) for cases and controls, respectively. Low carotenoid levels were found in the obese in relation to the non-obese (82% vs. 26,6%, p=0,0054 and OR=12,4). No statistically significant difference between the case and control groups was found for TC and cholesterol fractions, TG and retinol. The findings for the tested parameters were as follows: high TC (cases 30.4%, controls 21.7%; p=0.50), LDL-c (cases and controls 34.8%; p=0.50), low HDL-c (cases 17.4%, controls 26%; p=0.47), high TG (cases 31.8%, controls 17.4%, p=0.65) and high VLDL-c (cases 21.7% and controls 8.7%; p=0.20). CONCLUSIONS: The association of obesity, hyperlipidemia and low serum level of carotenoids, which are essential to antioxidant protection, may be one of many factors predisposing obese children to a high risk of atherosclerosis later in life.

Vitamina A e broncodisplaisa pulmonar / Vitamin and bronchopulmonary dysplasia

A broncodisplasia pulmonar tem evolução crônica que pode ser desencadeada por diversos fatores, como infecção, barotrauma, maturação pulmonar extra-uterina, espécies reativas de oxigênio e deficiência nutricional. A hipovitaminose A é a carência nutricional que mais se associa com tal enfermidade devido ao seu papel na diferenciação celular e reparação de lesão pulmonar. A baixa reserva hepática de vitamina A em recém-nascidos prematuros e de muito baixo peso, aliada a sua imaturidade fisiológica, os torna mais susceptíveis a hipovitaminose A e ao desenvolvimento de broncodisplasia pulmonar. Com o objetivo de investigar as evidências sobre o papel da suplementação de vitamina A na prevenção ou auxílio no tratamento da broncodisplasia pulmonar, realizou-se um levantamento bibliográfico em bases de dados do Medline e Lilacs nos últimos vinte anos (1984-2004). Os resultados n~eo definem um padrão no tratamento da broncodisplasia pulmonar, tanto na via de administração quanto na dosagem da vitamina A. Restam dúvidas quanto à dose administrada, tendo em vista os riscos decorrentes de uma possível toxidade por doses excessivas de vitamina A.

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.

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.

Níveis séricos de retinol em escolares de 7 a 17 anos no município do Rio de Janeiro / Serum retinol levels in school children, 7 to 17 years old in Rio de Janeiro, Brazil

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 <1,05æmol/L. RESULTADO: Encontrou-se um total de 10,30 por cento 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 por cento na faixa etária de 7 a 10 anos e 7,92 por cento na faixa etária de 10 a 17 anos). CONCLUSAO: 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.

Estado nutricional em vitamina A em escolares do Estado do Rio de Janeiro, Brasil / Vitamin A nutritional status of school children in the state of Rio de Janeiro, Brazil

Foram avaliados os níveis séricos de vitamina A em 663 escolares, entre 7 e 17 anos, de áreas urbana (n=574) e rural (n=89) do Estado do Rio de Janeiro, através do método Bessey et al. modificado e o ponto de corte < 1,05µmol/L foi utilizado para indicar níveis inadequados de vitamina A. A freqüência de níveis inadequados de retinol sérico encontrada foi 10,3 por cento na área urbana e 7,9 por cento na área rural, com menores níveis de retinol sérico no sexo masculino e dentre os mais jovens (11,98 por cento) e 13 por cento a faixa etária de 7 a 10 anos, respectivamente). Estes dados demonstram um importante nível de inadequação do estado nutricional de vitamina A nos escolares das regiões estudadas, justificando a adoção de medidas de combate e prevenção desta deficiência nutricional para este grupo populacional

Gestational nightblindness among women attending a public maternity hospital in Rio de Janeiro, Brazil.

This study evaluated the prevalence of gestational nightblindness among postpartum women seen at the University Maternal Hospital of the Federal University in Rio de Janeiro, Brazil and the association of this symptom with a biochemical indicator (serum retinol levels) and sociodemographic, anthropometric and antenatal care variables. In total, 262 postpartum women, who did not receive vitamin A supplementation during pregnancy, were interviewed. Gestational nightblindness was diagnosed through the standardized interview as proposed by WHO. Serum retinol levels were evaluated by spectrophotometry. Gestational nightblindness relating to low levels of serum retinol (<1.05 micromol/L, p = 0.000) was diagnosed in 17.9% of subjects interviewed. Less than five antenatal care appointments (odds ratio [OR] = 2.179; confidence interval [CI] 95% = 1.078 - 4.402) and a history of one or more miscarriage(s) (OR = 2.306; CI 95% = 1.185 - 4.491) were predictors for gestational nightblindness. These findings justify the need for nutritional counselling, aimed at improving the vitamin A nutritional status, especially among pregnant women with a history of previous miscarriages and poor antenatal care.

Impact of vitamin A megadose supplementation on the anthropometry of children and adolescents with non-hormonal statural deficit: a double-blind and randomized clinical study.

OBJECTIVE: To evaluate the intake of retinol and carotenoids, and their serum levels, as well as the impact of vitamin A supplementation on the anthropometry and body composition of children and adolescents with non-hormonal-related statural deficit. METHOD: Double-blind, randomized trial of 46 pre-pubertal patients, between 4 and 14 years of age, with normal growth rates. The subjects were divided into two groups, each with 23 individuals (Group I: Placebo; Group II: Vitamin A in a single megadose), and were evaluated at moments A and B with a six month interval. RESULTS: There were no statistically significant differences in serum retinol levels, anthropometry, growth velocity, or body composition, between moments A and B, in Group II. Carotenoids were significantly lower in Group I at moment B. The semi-quantitative food intake questionnaire showed that approximately 60.9% of the children and adolescents ingested less than half of the amounts of retinol and carotenoids recommended by the Food Guide Pyramid. Inadequate intake was more prevalent regarding vegetable and fruit carotenoid sources, with 75 and 70% of inadequacy, respectively. CONCLUSION: If one considers the inadequate food intake observed in the dietary evaluation in this study, it is possible that multiple micronutrient deficiencies could be involved in statural deficits. This could explain why vitamin A supplementation does not seem to influence growth in children and adolescents with statural deficit, as indicated by the present study. Thus in populations such as the one studied here, the supplementation with vitamin A should be integrated into comprehensive nutritional interventions, so as to possibly promote greater positive impact on linear growth.

[Hypovitaminosis A in Brazil: a public health problem]. / Hipovitaminose A no Brasil: um problema de saúde pública.

Vitamin A deficiency is considered one of the most important of the easily preventable public health problems in a number of countries, including Brazil. The objective of this study was to review the scientific literature in the MEDLINE and LILACS databases that was published between 1970 and 2000 concerning vitamin A deficiency, and to assess the occurrence of hypovitaminosis A in Latin America, especially Brazil. Our research showed that until around 1980 the public health concerns focused mainly on the importance of vitamin A in ensuring good vision. In the second half of the 1980s, epidemiological studies suggested that, on a population level, subclinical vitamin A deficiency could also have a negative effect on metabolic functions, with a great impact on childhood morbidity and mortality. Marginal vitamin A deficiency has been reported in all the regions of Brazil for which there are data available, with high prevalences in various age groups. This situation is inexcusable, given the health care technology and resources that are now available. There must be a commitment to reducing vitamin A deficiency in order to ensure the adequate development of future generations.

Deficiência de ferro e de vitamina A: avaliação nutricional de pré-escolares de Viçosa (MG/Brasil) / Iron and vitamin A deficiences: nutritional evaluation in pre-school children from the city of Viçosa (MG-Brazil)

A incidência de anemia por deficiência de ferro relacionada com a de vitamina A foi avaliada em 135 pré-escolares, de 3 a 6 anos de idade, de 3 creches municipais de Viçosa/MG. O estado nutricional dos pré-escolares foi avaliado pela determinação dos índices de peso para idade (P/I), altura para idade (A/I) e peso para altura (P/A). Os valores de escore-Z para os índices peso/idade (P/I), peso/altura (P/A) e altura/idade (A/I) foram utilizados como indicadores de desnutrição do tipo "stunting" ou "wasting". As crianças que estavam abaixo do ponto Z<-2 foram consideradas desnutridas. Avaliou-se, também, o consumo quantitativo de alimentos de cada criança pelo método da pesagem direta das refeições oferecidas nas creches, durante cinco dias úteis...

Estado nutricional de vitamina A no grupo materno-infantil / Nutritional status of vitamin A in the mother-child group

Revisa o conhecimento disponível na literatura sobre o estado nutricional de vitamina A no grupo materno-infantil. A vitamina A é um nutriente essencial para a reproduçäo. Durante a gestaçäo, há diminuiçäo dos níveis séricos de retinol, podendo ocorrer hipovitaminose A materna, com alteraçöes metabólicas, no sistema imunológico e na biodisponibilidade para o feto. Os efeitos da gestaçäo sobre o metabolismo da vitamina A näo estäo totalmente esclarecidos, sendo os mecanismos propostos baseados em achados experimentais. A carência de vitamina A materna também altera a disponibilidade desta vitamina no leite humano, importante fonte do nutriente nos primeiros meses de vida para lactentes. Considerando que a hipovitaminose A e suas conseqüências säo possíveis de ocorrer sem sinais detectáveis na mäe, com repercussäo fetal, a detecçäo precoce de mulheres em risco de carência deve ser uma preocupaçäo dos serviços de saúde, pois trata-se de carência nutricional com grande impacto sobre a saúde do binômio mäe-filho.

Valores séricos de vitamina A e teste terapêutico em pré-escolares atendidos em uma Unidade de Saúde do Rio de Janeiro, Brasil / Serum vitamin a levels and therapeutic test in preschool children attended in a Health Unit of Rio de Janeiro, Brazil

Foi avaliado o impacto da suplementação com doses maciças de vitamina A (200.000UI) em pré-escolares atendidos em unidade de saúde do Rio de Janeiro. Inicialmente avaliou-se o nível de retinol sérico e as medidas antropométricas em 175 pré-escolares atendidos pelo Serviço Materno-Infantil da Universidade Federal do Rio de Janeiro. Forneceu-se, então, uma dose maciça de 200 000 UI de vitamina A solicitando o retorno após 30 dias. Nas crianças que retornaram após este período (n=99), refez-se a avaliação de retinol sérico. A prevalência de hipovitaminose A (< 1,5 umol/L) foi de 34,3 por cento em todas as crianças avaliadas na primeira visita. Após a administração do suplemento vitamínico, a prevalência de hipovitaminose A nas crianças que voltaram ao serviço reduziu de 42,4 por cento para 3,0 por cento. A dose maciça beneficiou preferencialmente as crianças com níveis inadequados. Na amostra, apenas 4,6 por cento das crianças apresentavam desnutrição avaliada por medidas antropométricas. Não houve associação entre hipovitaminose A e renda familiar ou escolaridade dos pais. As taxas de prevalência encontradas indicaram que as crianças desta faixa etária são um grupo de risco para este problema nutricional. A reversão do quadro de carência provocada pelo suplemento vitamínico parece indicar que a ingestão inadequada de alimentos fonte de vitamina A seija um importante fator etiológico da hipovitaminose A. A prevalência encontrada também demonstrou que o problema não é exclusivo das áreas tradicionalmente pobres do país