Deficiencia de vitamina A y factores asociados en niños preescolares de la periferia de la ciudad de La Plata, Buenos Aires / Vitamin A deficiency and associated factors in preschoolers from the outskirts of La Plata, Buenos Aires

Introducción. La deficiencia de vitamina A (DVA) ha sido reconocida como un importante problema de salud pública en países en vías de desarrollo. Los niños en edad preescolar son grupos de riesgo en poblaciones vulnerables. El objetivo fue determinar la prevalencia de DVA y los factores asociados en una muestra de niños de edad preescolar. Material y métodos. Estudio de corte transversal que incluyó a niños de 1 a 6 años beneficiarios de planes sociales, atendidos en centros de atención primaria de la periferia de la ciudad de la Plata, Buenos Aires. Se determinó el contenido de vitamina A midiendo retinol sérico, por cromatografía líquida, y se registraron parámetros antropométricos e ingesta alimentaria. Se utilizó un modelo de regresión logística multinomial para evaluar la asociación entre las variables. Resultados. Se analizaron datos de 624 niños. La media geométrica de retinol fue 23,8 pg/dl (IC 95 %: 23,3-24,3). Las prevalencias de DVA y riesgo de DVA fueron 24,3 % y 57,4 %, respectivamente. Los niveles de retinol fueron significativamente menores en niños varones, con bajo peso y aquellos con bajo consumo (menor del primer tercilo de distribución). El análisis multivariable mostró asociación significativa entre DVA y el sexo masculino (OR: 1,93; IC 95 %: 1,15-3,24) y con el bajo consumo (OR: 1,48; IC 95 %: 1,15-2,62). Conclusión. La prevalencia de DVA hallada (24,3 %) constituye un importante problema de salud pública en esta población. Los factores asociados a dicha deficiencia fueron el sexo masculino y el bajo consumo.

Introduction. Vitamin A deficiency (VAD) has been recognized as an important public health problem in developing countries. Preschoolers account for risk groups within vulnerable populations. The objective of this study was to determine the prevalence of VAD and associated factors in a sample of preschoolers. Material and methods. Cross-sectional study with children aged 1-6 years receiving social assistance and seen at primary health care centers in the outskirts of the city of La Plata, Buenos Aires. Vitamin A levels were determined by measuring serum retinol with a liquid chromatography; anthropometric parameters and dietary intake were recorded. A multinomial logistic regression model was used to assess the association among outcome measures. Results. Data from 624 children were analyzed. The geometric mean of retinol was 23.8 pg/dL (95 % CI: 23.3-24.3). The prevalence of VAD and the risk for VAD were 24.3 % and 57.4 %, respectively. Retinol levels were significantly lower among boys, low-weight children, and those with low intake (below the first tertile of distribution). The multivariate analysis showed a significant association between VAD and male sex (odds ratio: 1.93; 95 % CI: 1.15-3.24) and between VAD and low intake (odds ratio: 1.48; 95 % CI: 1.15-2.62). Conclusion. The prevalence of VAD (24.3 %) is a major public health problem in this population. VAD-associated factors were male sex and low vitamin A intake.

Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5%) preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age.

Iron deficiency and anemia are associated with low retinol levels in children aged 1 to 5 years / Deficiência de ferro e anemia estão associadas com baixos níveis de retinol em crianças de 1 a 5 anos

OBJECTIVE: To analyze the occurrence of anemia and iron deficiency in children aged 1 to 5 years and the association of these events and retinol deficiency. METHODS: This was an observational analytic cross-sectional study conducted in Vitoria, ES, Brazil, between April and August of 2008, with healthy children aged 1 to 5 years (n = 692) that lived in areas covered by primary healthcare services. Sociodemographic and economic conditions, dietary intake (energy, protein, iron, and vitamin A ingestion), anthropometric data (body mass index-for-age and height-for-age), and biochemical parameters (ferritin, hemoglobin, and retinol serum) were collected. RESULTS: The prevalence of anemia, iron deficiency, and retinol deficiency was 15.7%, 28.1%, and 24.7%, respectively. Univariate analysis showed a higher prevalence of anemia (PR: 4.62, 95% CI: 3.36, 6.34, p < 0.001) and iron deficiency (PR: 4.51, 95% CI: 3.30, 6.17, p < 0.001) among children with retinol deficiency. The same results were obtained after adjusting for socioeconomic and demographic conditions, dietary intake, and anthropometric variables. There was a positive association between ferritin vs. retinol serum (r = 0.597; p < 0.001) and hemoglobin vs. retinol serum (r = 0.770; p < 0.001). CONCLUSIONS: Anemia and iron deficiency were associated with low levels of serum retinol in children aged 1 to 5 years, and a positive correlation was verified between serum retinol and serum ferritin and hemoglobin levels. These results indicate the importance of initiatives encouraging the development of new treatments and further research regarding retinol deficiency. .

OBJETIVO: Analisar a ocorrência de anemia e de deficiência de ferro em crianças de 1 a 5 anos e a associação destes desfechos com a deficiência de retinol. MÉTODOS: Trata-se de um estudo observacional analítico do tipo transversal, realizado no município de Vitória - ES, entre abril e agosto de 2008, com crianças (n = 692) saudáveis de 1 a 5 anos, residentes em áreas de abrangência de Unidades Básicas de Saúde. Foram avaliados dados sociodemográficos, econômicos, dietéticos (ingestão de energia, proteína, ferro e vitamina A), antropométricos (índice de massa corporal-por-idade e estatura-por-idade) e bioquímicos (níveis séricos de ferritina, hemoglobina e retinol). RESULTADOS: Detectou-se anemia, deficiência de ferro e deficiência de retinol em 15,7%, 28,1% e 24,7% das crianças, respectivamente. A análise univariada evidenciou maior ocorrência de anemia (RP: 4,62; IC 95%: 3,36; 6,34, p < 0.001) e de deficiência de ferro (RP: 4,51; IC 95%: 3,30; 6,17, p < 0.001) entre crianças que apresentavam deficiência de retinol. As mesmas relações se mantiveram após o ajuste pelas variáveis socioeconômicas, demográficas, dietéticas e antropométricas. Houve relação positiva entre os valores de ferritina sérica vs. retinol (r = 0,597; p < 0,001) e hemoglobina vs. retinol (r = 0,770; p < 0,001). CONCLUSÕES: A anemia e a deficiência de ferro mostraram-se associadas com baixos níveis de retinol em crianças de 1 a 5 anos, e houve correlação positiva dos níveis de retinol com os de ferritina sérica e hemoglobina. Isto torna importante iniciativas que estimulem o desenvolvimento de novos tratamentos e a ampliação de pesquisas em relação à deficiência ...

Prevalence and factors associated with vitamin A deficiency in children and adolescents / Prevalência e fatores associados à deficiência de vitamina A em crianças e adolescentes

Objective: To identify the prevalence and factors associated with vitamin A deficiency (VAD) in children and adolescents. Methods: This was a cross-sectional study involving 546 schoolchildren, aged between 7 and 14 years, of both genders, enrolled in public elementary schools. Blood was collected for measurement of serum retinol. The retinol concentration in the samples was determined by high performance liquid chromatography (HPLC). Data were collected on anthropometrics, dietary, demographic, and socioeconomic factors. Polytomous logistic regression was used to evaluate the associations of interest. Results: Approximately 27.5% of the students had retinol values < 30 μg/dL. The multivariate analysis showed, after the appropriate adjustments, a positive and statistically significant association of moderate/severe VAD (OR = 2.19; 95% CI 1.17 to 4.10) and marginal VAD (OR = 2.34; 95% CI 1.47 to 3.73) with age < 10 years. There was also association of VAD moderate/severe (OR = 2.01; 95% CI 1.01 to 5.05) and borderline VAD (OR = 2.14; 95% CI: 1.08 to 4.21) with the anthropometric status of underweight. Lower intake of retinol was detected among those with severe VAD. Conclusion: VAD is a health concern among children and adolescents. Lower weight and younger schoolchildren had greater vulnerability to VAD. .

Objetivo: Identificar prevalência e fatores associados à deficiência de vitamina A (DVA) entre crianças e adolescentes. Métodos: Estudo transversal envolvendo 546 escolares, com idade entre 7 e 14 anos, de ambos os sexos, matriculadas na rede pública do ensino fundamental. O sangue foi coletado para dosagem dos níveis séricos de retinol. A concentração de retinol das amostras foi determinada pelo método da cromatografia líquida de alta eficiência (CLAE). Coletaram-se dados antropométricos, alimentares, demográficos e socioeconômicos. Utilizou-se da regressão logística politômica para avaliar as associações de interesse. Resultados: Aproximadamente 27,5% dos estudantes apresentaram valores de retinol < 30 μg/dL. Em análise multivariada, verificou-se, após devidos ajustes, associação positiva e estatisticamente significante da DVA moderada/grave (OR = 2,19; IC 95%: 1,17-4, 10) e da DVA marginal (OR = 2,34; IC 95%: 1,47-3,73) com a idade < 10 anos. Verificou-se, igualmente, associação da DVA moderada/grave (OR = 2,01; IC 95%: 1,01-5,05) e DVA marginal (OR = 2,14; IC 95%: 1,08-4,21) com o estado antropométrico magreza. Menor consumo de retinol foi detectado entre aqueles com DVA grave. Conclusão: A deficiência de vitamina A configura-se como um problema de saúde preocupante entre os escolares e adolescentes. Constatou-se maior vulnerabilidade dos escolares de baixo peso e mais jovens à DVA. .

Deficiencia de vitamina A e fatores associados em criancas de areas urbanas / Vitamin A deficiency and associated factors in children in urban areas

OBJETIVO: Analisar a prevalência da deficiência de vitamina A em crianças e os fatores associados. MÉTODOS: Estudo de corte transversal de base populacional realizado com 1.211 crianças de seis a 59 meses de idade, de ambos os sexos, procedentes da área urbana de nove cidades do estado da Paraíba, Brasil. O estado nutricional de vitamina A foi avaliado pelas concentrações séricas de retinol e presença de infecção subclínica avaliada pelas concentrações de proteína C-reativa. Foram investigadas as condições socioeconômicas, demográficas, de saneamento, além da suplementação prévia com vitamina A. Foram consideradas com deficiência de vitamina A as crianças com concentrações de retinol sérico < 0,70 µmol/L. Níveis séricos de vitamina A < 0,70 µmol/L com prevalência ≥ 20% foram considerados como grave problema de saúde pública. Análises uni e multivaridas foram conduzidas para testar associações estatísticas (p < 0,05). RESULTADOS: A prevalência de deficiência de vitamina A foi de 21,8% (IC95% 19,6;24,2), mostrando associação com a presença de infecção subclínica e ausência de água no domicílio. A prevalência de deficiência de vitamina A foi de 21,8% (IC95% 19,6;24,2). Após ajuste para confundimento, a deficiência de vitamina A mostrou-se associada com a presença de infecção subclínica e com a ausência de água no domicílio. A ocorrência da deficiência de vitamina A foi quatro vezes maior (IC95% 1,49;10,16) em crianças com infecção subclínica e sem água no domicilio, comparativamente às crianças ...

OBJECTIVE To estimate the prevalence of vitamin A deficiency and its associated factors in children. METHODS A cross-sectional population-based study, involving 1,211 children of both sexes, aged between six and 59 months old, was carried out in the urban zone of 9 cities in the state of Paraiba, Northeastern Brazil. Vitamin A status was assessed by serum retinol levels (high performance liquid chromatography – HPLC) and subclinical infection was assessed by C-reactive protein concentrations. Socioeconomic, demographic and sanitation conditions, as well as vitamin A supplement intake, were also evaluated. Children with serum retinol concentrations RESULTS The prevalence of vitamin A deficiency was 21.8% (95%CI 19.6;24.2), showing an association with subclinical infection and lack of indoor plumbing. The prevalence of vitamin A deficiency was 21.8% (95%CI 19.6;24.2). After adjustment, vitamin A deficiency was found to be linked with subclinical infection and lack of indoor plumbing. Vitamin A deficiency was four times higher (CI95% 1.49;10.16) in children with subclinical infection whose homes were without indoor plumbing, compared to children who were not infected and with indoor plumbing in their homes. CONCLUSIONS Despite activities aimed at the prevention and control of vitamin A deficiency, hypovitaminosis A, remains a public health concern among children under five. .

Deficiencia de vitamina A en adolescentes no gestantes y gestantes de Maracaibo, Venezuela / Vitamin A deficiency in non pregnant and pregnant adolescents from Maracaibo, Venezuela

Antecedentes: La deficiencia de vitamina A (DVA) es un problema nutricional de salud pública en el mundo. Durante el embarazo se ha asociado con incremento en la morbilidad y mortalidad materno-infantil. Objetivo: Determinar en adolescentes no gestantes y gestantes venezolanas, el estado nutricional de la vitamina A (ENVA). Método: Se realizó un estudio transversal, descriptivo y controlado, en 235 adolescentes mujeres (edad: 16,76 +/- 1,48 años); 75 no gestantes y 160 gestantes. El ENVA fue evaluado según valores de retinol sérico (RS) por cromatografía líquida de alta eficacia (HPLC) y citología de impresión conjuntival (CIC). Resultados: En gestantes y no gestantes la prevalencia de CIC anormal (37,5 por ciento vs 48 por ciento; p>0,05) y afectación del ENVA (41,24 por ciento vs 13,34 por ciento; p=0,0001) fue alta; significativamente mayor durante el segundo y tercer trimestre de gestación (p<0,0002). Las gestantes mostraron una disminución significativa de los valores promedio RS (p<0,0001), una correlación inversa no significativa con la edad gestacional y 4,56 veces mayor probabilidad de presentar afectación del ENVA (OR=4,56; IC95 por ciento: 2,0-10,23) que las no gestantes. Conclusión: La alta prevalencia de DVA observada en este trabajo, representa un problema de salud pública en adolescentes venezolanas, por lo que este grupo vulnerable requiere intervención inmediata.

Background: Vitamin A deficiency (VAD) is a public health nutrition problem in the developing world. VAD had been associated with increased risk of maternal and childhood mortality and morbidity. Objective: To determine vitamin A status (VAS) between non pregnant and pregnant adolescents from Maracaibo-Vene-zuela. Methods: A cross-sectional and descriptive study was conducted in 235 female adolescents (16.76 +/- 1.48y old); non pregnant (n=75) and pregnant (n=160). Vitamin A status was assessed by using serum retinol concentrations (SRC) and conjuctival impression cytology (CIC). SRC were measured by high-performance liquid chromatography and CIC. Results: In pregnant and non pregnant adolescents the prevalence of CIC abnormal (37.50 percent vs 48 percent) and non normal VAS (41.24 percent vs 13.34 percent; p=0.0001) were high, predominantly in the second and third trimester of pregnancy (p<0.0002). Pregnant adolescents showed significative reduction of the mean SRC values (p<0.0001), while gestational age had a negative and no significant relationship with SRC. The odds ratio for pregnant adolescents with non normal VAS was 4.56 (95 percentIC: 2.0-10.23), resulting significantly more frecuent non normal VAS in pregnant adolescents than non pregnant adolescents. Conclusions: The high prevalence of VAD found in this work, is a public health problem in venezuelan female adolescents and this vulnerable group require immediate interventions.

Vitamina A e diabetes gestacional: [revisão] / Vitamin A and gestational diabetes: [review]

O diabetes mellitus (DM), patologia de caráter crônico e evolutivo, atualmente apresenta configuração de epidemia mundial. O diabetes gestacional, condição associada tanto à resistência à insulina quanto à diminuição da função das células-β, também caracteriza-se pela elevada incidência em diversas populações e grupos étnicos. Recentemente têm sido constatadas fortes evidências para o comprometimento dos níveis de retinol de gestantes com DM em resposta à evolução dessa patologia. Essa condição torna as gestantes diabéticas mais propensas a apresentar estado bioquímico marginal ou deficiente em vitamina A quando comparadas com as de gestação saudável. Dessa maneira, tendo conhecimento sobre o papel fisiológico da vitamina A e as consequências do DM na gestação, esta revisão visa esclarecer o impacto da instalação do DM sobre os níveis de retinol dessas gestantes, bem como, as consequências que o estado de deficiência em vitamina A poderá causar para essas mulheres e para seus lactantes.

Diabetes mellitus (DM) a pathology with chronic evolution, has now acquired a connotation of global epidemic. Gestational diabetes, a condition associated with insulin resistance and decreased β-cells function is also characterized by a high incidence in different populations and ethnic groups. Recently strong evidence has been found for involvement of retinol levels of pregnant women with DM due to the pathology’s evolution. This condition makes these diabetics prone to have a marginal biochemical profile or a vitamin A deficiency when compared to those of healthy pregnant women. Therefore, with an awareness of the physiological role of vitamin A and consequences of diabetes during pregnancy, this review intends to clarify the impact of DM on retinol levels of these pregnant women and the consequences that vitamin A deficiency may cause to these women and their infants.

Oxidative stress and antioxidant status in cardiovascular diseases in population of western Nepal.

OBJECTIVES: To observe if there is any connectivity between oxidative stress and cardiovascular diseases (CVDs). MATERIALS AND METHODS: Patients suffering from different cardiovascular diseases (hypertension, ischemic heart disease, rheumatic heart disease) attending Manipal Teaching Hospital, Pokhara and strictly matched controls were selected for this study. Oxidative stress (OS) was measured by plasma thiobarbituric acid reacting substances (TBARS) where as antioxidant status was measured by estimating vitamin E, vitamin C and total antioxidant activity (TAA) in plasma. RESULTS: The mean level of TBARS, TAA, vitamin C and E were 2.20+0.43 nmol/ml, 547+98 mol/l, 0.88+0.15 mg/dl and 0.75+0.20 mg/dl respectively in patients. The respective values in controls were 1.86+0.43 nmol/ml, 859+139 mol/l, 0.94+0.15 mg/dl and 1.10+0.30 mg/dl. Although the OS seems to be raised in patients, is practically insufficient to oxidize biomolecules and induce CVDs. Despite vitamin C and E levels being well within normal limits, the TAA was significantly and considerably lower in patients. This is a highly interesting observation suggesting that dietary antioxidants other than these vitamins were preferentially consumed to control OS because procedure for TAA used in this study practically measures only total dietary antioxidants. CONCLUSION: OS does not appear to be an etiological factor for the cardiovascular diseases; rather slightly raised OS in patients seems to be a consequence. Further the raised OS was not due to lower nutrient antioxidant (vit. C and vit. E) in the local population studied herein.

Hipovitaminose A em pré - escolares de creches públicas do Recife: indicadores bioquímico e dietético / Vitamin A deficiency among preschool children attending public day care centres of Recife: biochemical and dietetic indicators

OBJETIVO: Estimar a prevalência de hipovitaminose A em pré-escolares de creches públicas da cidade do Recife, Estado de Pernambuco, Brasil. MÉTODOS: Estudo de corte transversal, envolvendo 311 crianças menores de cinco anos, de ambos os sexos, aleatoriamente selecionadas, e avaliadas pelos indicadores bioquímico (retinol sérico), dietético (inquérito de consumo alimentar) e antropométrico (peso/idade, altura/idade e peso/altura). RESULTADOS: A prevalência de níveis de retinol sérico baixos (<0,70æmol/L) foi de 7,0 por cento, caracterizando a deficiência de vitamina A como problema de saúde pública do tipo leve, segundo critérios da Organização Mundial de Saúde. Cerca de 78,0 por cento das crianças apresentaram adequação do consumo de vitamina A, considerando-se as cifras recomendadas pela Dietary Reference Intakes, 2001. A distribuição dos níveis séricos de retinol e do consumo alimentar de vitamina A foi homogênea, segundo o sexo. No entanto, crianças na faixa etária de 12 a 48 meses mostraram menor consumo de alimentos fonte de vitamina A em relação às crianças das demais faixas etárias (p<0,05). A prevalência de baixo peso foi de 7,5 por cento, de retardo do crescimento linear de 8,1 por cento e de desnutrição aguda de 1,8 por cento. A hipovitaminose A não mostrou correlação com a desnutrição energético-protéica (p>0,05). O consumo dietético de vitamina A mostrou sensibilidade reduzida (43,0 por cento) e baixíssimo valor preditivo positivo (6,8 por cento) no diagnóstico da hiporretinolemia. CONCLUSÃO: A identificação de grupos populacionais vulneráveis, bem como a seleção de indicadores fidedignos do estado nutricional de vitamina A, são elementos essenciais para o diagnóstico e o planejamento de ações visando à prevenção e ao controle dessa carência nutricional específica.

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.

Deficiencias de hierro y de vitamina A y prevalencia de anemia en niños y niñas de 6 a 24 meses de edad en Chaco, Argentina / Iron and vitamin A deficiencies and prevalence of anemia in boys and girls between 6 to 24 months of age in Chaco, Argentina

To determine the prevalence of anemia, and iron (ID) and vitamin A deficiencies aiming at their prevention, 414 children between 6 and 24 months of age, were randomly selected from the whole province of Chaco. A sociodemographic survey was implemented, and hemoglobin (Hb), plasma ferritin and retinol were measured. Anemia prevalence (Hb < 110 g/L) was 66.4 per cent, without differences between age groups, and included 18 per cent with Hb < 90 g/L. These cases were significantly less in children 6-8 month of age (5.1 per cent) than in the others (approximately equal to 20 per cent) (P: 0.007). Mean Hb was also higher in 6-8 months old children and was associated with lower prevalence of ID (ferritin < 12 micrograms/L) (p < 0.000) but not with age (p = 0.8865). ID already present, however, in 36.6 per cent of children in this age group, reached a prevalence of 72.9 per cent in children older than 18 months. Anemia prevalence was significantly higher in males, in children whose birth weight was < 3000 g, in those who had never taken iron supplements and among the poor, both structural and by income. Retinol values < 20 micrograms/dl occurred only in 5.1 per cent of children. Iron nutrition prior to, during pregnancy and in children during the first 2 years of life must be improved by joining strategies based on community empowerment aimed at improving dietary iron, assuring effective preventive supplementation and promoting the opportune umbilical cord ligation.

Plasma vitamin A and C status of in-school adolescents and associated factors in Enugu State, Nigeria.

The study was undertaken to determine the intake of vitamin A and C and plasma concentrations of these vitamins among in-school adolescents. The factors affecting the vitamin status of these adolescents were also determined. Data for this report were obtained from a cross-sectional survey of 600 in-school adolescents in Nsukka local government area (LGA) of Enugu State, Nigeria. Ninety and 45 of the adolescents were randomly selected for determining plasma concentrations of vitamin A and C and intake of these vitamins respectively. Dietary assessment was done using a three-day weighed food intake method. Venous blood samples were collected and used for determining plasma vitamin A using the trifluoroacetic acid (TFA) method, while plasma vitamin C was determined by the thiourea method. Values obtained were matched against standards. The intake of vitamin A by all the adolescents was adequate (126-137% of recommended intake), while the intake of vitamin C was inadequate (51-91% of recommended intake). The mean intake of vitamin C was higher among males (23.7 +/- 0.71-27.3 +/- 8.0) than among females (15.3 +/- 2.8-19.5 +/- 5.1). Despite the adequate intake of vitamin A, 40% of the male and 32% of the female adolescents had low plasma concentrations of the vitamin (< 20 microg/dL). On the other hand, concentrations of plasma vitamin C were low among about 47% of these adolescents. Using multiple regression analysis, the two most important variables influencing vitamin A status were household size (b = -0.629; p < 0.0 1) and nutrition knowledge (b = -1.372; p < 0.01), while for vitamin C status, these were household size (b = -0.110; p = 0.05) and age (b = 0.226; p < 0.05). The daytime students had a significantly (p < 0.05) better vitamin A and C status than the boarders. The prevalence of vitamin A and C deficiencies among the adolescents may be more than estimated due to inadequate intake and/or poor bioavailability. This may pose a serious health risk for adolescents. There is, therefore, a need for adequate nutrition education and awareness about healthy lifestyles among Nigerian adolescents.

Vitamin A status in premature infants.

BACKGROUND: Premature infants are at risk of vitamin A deficiency due to inadequate transplacental transport, inadequate storage and increased tissue utilization. Previous studies reported a significant decrease in serum vitamin A levels in premature infants at birth compared to those of full term infants. OBJECTIVE: To determine serial changes of plasma vitamin A status during the first month of life in 19 healthy, very low birth weight premature infants. METHOD: Subjects were fed with premature infant formula and received multivitamin supplementation. Plasma vitamin A concentrations were measured at 7, 14, and 30 days of age. RESULTS: Plasma vitamin A levels at 7,14 and 30 days of age were 24.63 +/- 6.08, 30.97 +/- 5.26 and 30.68 +/- 7.14 microg/dl, respectively. Plasma vitamin A levels at age 7 days were significantly lower than those at 14 and 30 days of life (p < 0.001). Three infants out of 19 (16%) had low plasma vitamin A (<20 microg/dl) at 7 days. At 14 and 30 days of age, all infants had normal plasma vitamin A levels. CONCLUSION: The results suggested that healthy premature infants were prone to subclinical vitamin A deficiency during the first week of life which could be treated by adequate enteral feeding and routine multivitamin supplementation. A high dose of vitamin A supplementation was not necessary in healthy premature infants.

role of vitamin A in enhancing humoral immunity produced by antirabies vaccine

We tested the effects of vitamin A supplementation on the antibody titre of 40 healthy volunteers [age range: 10-35 years], who had received a complete course of antirabies vaccine [5 injections over 30 days]. After determining the baseline serum vitamin A status of 80 volunteers, 20 pairs were matched for serum vitamin A level, body mass index, age, sex and socioeconomic status. One person from each pair was randomly assigned to an experimental or control group. The experimental group received vitamin A and antirabies vaccine. Controls received only the vaccine. The experimental group had significantly greater [2.1 times] serum antirabies titre than controls. This finding is an important step towards improving the economy of dosage of antirabies vaccines

Evaluation of vitamin A status during pregnancy.

Adequate maternal vitamin A nutrition is essential for successful pregnancy outcome and estimation of serum retinol among pregnant women enables a precise and objective assessment of vitamin A status, during pregnancy, even in subclinical state. In order to evaluate vitamin A status during pregnancy, and its relationship with personal and pregnancy related variables of the mother, 300 antenatal clinic attenders were interviewed at RG Kar Medical College and Hospital, Calcutta and tested for serum retinol, using Carr-Price test. Serum retinol values less than 30 microg/dl and 20 microg/dl, in this study, were considered as poor and severe vitamin A deficiency respectively. According to this 14.7% and 4% pregnant women were found to be suffering from poor and severe vitamin A deficiency respectively. Clinical signs of vitamin A deficiency (eg, nightblindness) were reported only among 60% cases of the deficient population. The problems of vitamin A deficiency were associated with low literacy and poor nutritional status of the mother, advanced gestational age of current pregnancy,increased number of pregnancies, shorter interval between births and poor dietary intake of vitamin A rich foods during pregnancy. The study thus raises the question of supplementation of vitamin A, during pregnancy, in Indian context where habitual diets are either inadequate or deficient in vitamin A.

Retinol sérico en mujeres mexicanas urbanas durante el periodo perinatal / Serum retinol in urban Mexican women during the perinatal period

Objetivo. Establecer la prevalencia de deficiencia de vitamina A durante el embarazo y la lactancia en un grupo de mujeres mexicanas urbanas. Material y métodos. Se invitó a participar a un grupo de gestantes que acudián a control prenatal, que carecían de patología agregada y contaban con menos de 20 semanas de embarazo. Fueron evaluadas tres veces durante el embarazo y hasta la semana 24 del posparto. La determinación de vitamina A en suero se realizó por cromatografía de líquidos de alta presión. Se consideró como punto de corte para riesgo de deficiencia una concentración de retinol > 1.05 µmol/L. Resultados. En las tres evaluaciones durante la gestación las concentraciones de vitamina A fueron de 2.34 ñ 0.70, 2.41 ñ 1.03 y 1.86 ñ 0.66 µmol/L, respectivamente, lo cual muestra una disminución significativa. Sin embargo sólo 1/30 se ubicó por debajo del punto de corte aceptado para considerar riesgo de deficiencia y ninguno para deficiencia. Durante el posparto las concentraciones se conservaron relativamente constantes, alrededor de 2.10 µmol/L. La práctica de la lactancia no tuvo impacto sobre las concentraciones séricas de retinol, no así la pérdida de peso. Conclusiones. En la población estudiada no se documentaron casos de deficiencia de vitamina A durante el periodo perinatal. La pérdida de peso materna tiene influencia sobre las concentraciones de retinol en el posparto

Efecto de la suplementación con una dosis masiva de vitamina A en niños de 6 a 36 meses de edad / Effect of massive vitamin A supplement in children from 6 to 36 months of age

Objetivo. Evaluar el impacto de la suplementación con una dosis masiva de vitamina A en el estado nutricio de dicha vitamina y del hierro, en niños de zonas urbanas marginadas de Hermosillo, Sonora, México. Material y métodos. Se seleccionaron 60 niños (6-36 meses), a los que se les administró una dosis de 100 00 UI (6-12 meses) y 200 000 UI (12-36 meses) de vitamina A en el Día Nacional de Salud de la Secretaría de Salud (junio de 1994). Se midieron niveles séricos de retinol, carotenioide, hierro, transferrina y ferritina, en tres fases: basal, a las dos semanas y después de tres meses. Resultados. En la primera fase, la mediana de retinol fue 0.7 µmol/l; en la segunda aumentó a 0.97 µmol/l (p< 0.001), y en la tercera disminuyó a 0.83 µmol/l (p> 0.05). Un 6.3 por ciento de los niños presentó deficiencia severa de vitamina A al inicio, y no se encontró ningún caso en las fases posteriores a la suplementación. En la fase basal, 42 por ciento de los casos presentaron deficiencia moderada y la mayoría fue normal en las siguientes fases. No hubo diferencias en los niveles de hierro y transferrina (p> 0.05), pero sí en ferritina (p< 0.001), lo que indica un mejoramiento en las reservas de hierro a los tres meses. Conclusiones. Las campañas de distribución de dosis masivas pueden tener un impacto importante en el estado nutricio de vitamina A y hierro