Hernando Flores

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.

Hipovitaminose A em recém-nascidos em duas maternidades públicas no Rio de Janeiro, Brasil

O estado nutricional de vitamina A foi avaliado, atraves dos niveis de retinol no sangue do cordao umbilical, em 253 recem-nascidos assistidos em duas maternidades publicas do Municipio do Rio de Janeiro. Independentemente da idade gestacional e do peso ao nascer, a prevalencia de valores baixos de retinol (< 1,05 µmol/l) foi elevada (55,7%). Em criancas com baixo peso, essa prevalencia chegou a 68,7%. Confirmando uma serie de observacoes de outros autores, nao se observou qualquer associacao entre estado nutricional, avaliado antropometricamente, e niveis de retinol. Os resultados mostram que, na amostra investigada, a prevalencia de hipovitaminose A nos recem-nascidos e comparavel as cifras que se encontram nas regioes mais pobres do mundo, e sugerem a necessidade de se prestar especial atencao a esse grupo populacional por ser, entre os grupos de risco, o mais vulneravel aos efeitos deleterios da carencia marginal de vitamina A, em razao do rapido crescimento nos primeiros meses de vida.Vitamin A status (umbilical cord retinol levels) of 253 newborns in two public hospitals of Rio de Janeiro showed a high prevalence (55. 7%) of deficiency (retinol levels below 1.05 micromol/L). This rate of vitamin A deficiency (VAD) was independent of other nutritional and anthropometric parameters, such as low birth weight or small for gestational age. These data suggest that newborns can be as vulnerable to VAD as other population groups considered at high risk. They also suggest that special attention should be paid to this group, actually the most vulnerable to the harmful effects of VAD. Hypovitaminosis A should be among the first diagnostic hypotheses when an infant presents with an abnormality

Valores séricos de vitamina A e teste terapêutico em pré-escolares atendidos em uma Unidade de Saúde do Rio de Janeiro, Brasil

The impact of a massive dose of vitamin A on preschool children attended in a health unit from Rio de Janeiro was evaluated. Initially, serum retinol levels and anthropometric measurements were determined in 175 preschool children attended in the Childrens Service of the Universidade Federal do Rio de Janeiro, after which a massive (200.000 IU) dose of vitamin A was provided. The children were requested to return to the unit after 30 days. Serum retinol levels were measured in the children who returned (n=99). The prevalence of low (below 1.05 µmol/L) levels of circulating retinol was of 34.3% in all children evaluated in the first attendance. After 30 days the prevalence was reduced from 42.4 to 3.0%. The lower the initial retinol levels the better the benefit from the massive dose. The proportion of children with protein-energy malnutrition was of 4.6%, but no clear association was found between vitamin A deficiency and protein-energy malnutrition. Vitamin A deficiency was independent of the household income and educational level of the parents. The response of children with vitamin A deficiency to the massive dose indicates that a low vitamin A intake may play an important role in the etiology of the problem. The prevalence figures also demonstrate that this problem is not exclusive of the traditionally poor areas of the country.

Teratogenia da vitamina A

The vitamin A is essential to the preservation and the normal functioning of tissues, as well as, to the growth and development. In the human being it has indirect evidence that the vitamin A in excess, during the first weeks of gestation is teratogenic. Of the opposite, it does not have doubts on the deleterious effect, of a devoid feeding in this micronutrient and on the availability of the knowledge technician to prevent them. The concern with the fact of that the vitamin A would lead it the teratogenicity in human beings, has delayed the implementation of combat programs the vitamin A lack, mainly reaching the programs of food enrichment. Literature is controverted and makes use of few information on the doses for supplementation of pregnant. As retinol circulating maternal is controlled homeostatic after the food consumption vitamin source, it expects after same metabolic reply the strengthened food consumption, indicating that it does not have teratogenicity risk. Consequently, highly seems improbable that the consumption of enriched foods or vitamin supplements the daily pay-formed one, in habitual the single doses, has teratogenic effect in the man.

Flocos desidratados de abóbora na prevenção da carência de vitamina A em pré-escolares de uma creche

OBJECTIVE: This study assessed the effectiveness of dehydrated pumpkin flakes for elevating serum retinol and the relative dose response in preschoolers. METHODS: Vitamin A intake was determined by dietary survey. The flakes were analyzed microbiologically and for carotenoid content. The children were then given 6 grams of flakes per day during lunch for 90 days. The relative dose response essay was done at baseline and end of intervention. Fasting blood samples were collected at baseline, 30 and 90 days to determine serum retinol levels by spectrophotometry. RESULTS: Microbiological analyses showed that the flakes were suitable for consumption. The mean serum retinol level of the children increased from M=1.438 (SD=0.45µmol/L) at baseline to M=1.659 (SD=0.51µmol/L) at 30 days and M=1.928 (SD=0.70µmol/L) at 90 days. At the beginning of the study, 18.5% of the children had serum retinol levels below 1.05µmol/L. This percentage dropped to 7.6% after 30 days and 0% after 90 days. At the end of the study period (90 days), no child had a positive relative dose response. CONCLUSION: Pumpkin flakes efficiently increase serum retinol levels and hepatic vitamin A reserves in preschoolers.

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.

Hepatic retinol levels in individuals deceased from several causes

Purpose – The aim of the present work is to evaluate the hepatic retinol levels in individuals deceased from several causes in the municipal district of Rio de Janeiro.Design/methodology/approach – This study was conducted at Instituto Medico Legal (IML/RJ) by researching 236 necropsied individuals from several causes, at the age between 1 and 89, whose samples of the liver were obtained through necropsies up to 48 hours post morten. The determination of the hepatic levels of retinol was performed through the spectrofotometrical dosage. As a cut‐off point for vitamin A deficiency (VAD) was considered 20 μg g−1 of the hepatic tissue.Findings – The mean retinol hepatic reserve evaluated according to the causa mortis was 281.55 μg per gram in subjects died from violent death, significantly higher than in other causa mortis (165.67 μg per gram in coronary heart disease, 226.89 μg per gram in infectious disease, 121.27 μg per gram in other chronic diseases and 214.87 μg per gram in other diseases, p<0.05). A p...