No description available.

Malaria remains a major cause of morbidity and death, especially in developing countries. The effectiveness of conventional antimalarial drugs is waning and there is an urgent need for novel therapeutic approaches. An understanding of malaria parasite biology should facilitate the development of effective therapies that prevent and/or treat malaria. The present studies explore the potential of vitamin A (retinol) as an antimalarial agent. Retinol may act by changing the oxidant milieu within the malaria parasite. Therefore, the nature and consequences of oxidant injury during malaria infection, and its treatment with retinol, have also been explored. The antimalarial potential of retinol was characterised using an established in vitro culture system allowing assessment of efficacy through [3H]-hypoxanthine uptake at different erythrocytic stages of development of Plasmodium falciparum. Retinol losses during culture were significant (>50%). After adjusting for these losses, all parasite stages (early rings to mature trophozoites) showed similar retinol sensitivity, with values of the mean assayed concentration resulting in 50% growth inhibition (IC50) ranging from 10.1 to 21.4 μM. This range was above that in normal human serum (<3 μM) but below that associated with haemolysis in culture (>43 μM). Retinol pre-treatment of uninfected erythrocytes did not inhibit merozoite invasion. Retinol-treated parasites exhibited vacuolisation of the food vacuole and membrane rupture. A P. berghei murine model was used to determine the in vivo preventive and therapeutic efficacy of retinol. Multiple-dose retinol given to healthy Swiss mice before parasite inoculation reduced parasitaemia by 30%, a result comparable to the previously reported reduction in morbidity after vitamin A supplementation in children. A lesser reduction in parasitaemia of 10% was observed when retinol was given after the parasitaemia reached 10-15%. Retinol was ineffective in reducing parasitaemia when given either as single-dose supplementation post-inoculation or at regular intervals before and after infection. Retinol supplementation did not change plasma retinol concentrations during malaria infection whether or not retinol was given, but malaria attenuated the increase in liver retinol content. These data suggest that retinol has most value as prophylaxis. In contrast to published data from humans, previously healthy mice did not develop low plasma retinol concentrations during acute infection

Thesis (doctoral)--University of Uppsala, 1984. / Includes bibliographical references (p. 29-37).

In this report we describe the development of a method for the concurrent reversed-phase high-performance liquid chromatographic separation and photodiode array detection of human plasma retinol, tocopherols and carotenes. For a single sample injection, retinol, retinyl acetate, α- tocopherol, γ-tocopherol, α-tocopheryl acetate, all-trans-α-carotene and all-trans-β-carotene, as well as the mono-cis geometrical isomers of β- carotene were separated and detected. Analytical separations were performed at a subambient temperature (0°C) over a Suplex pKb-100 reversed-phase analytical column with an isocratic mobile phase of methanol-methyl tert.- butyl ether-water (80:20:5, v/v/v) at a flow-rate of 0.8 ml/min for 60 min. Standards and samples were reconstituted in ethanol, and typically, 50 μl was injected for analysis. By HPLC, compounds of interest were clearly resolved and detectable at the picomole level.

The fat-soluble vitamin A, which is chemically referred to retinol (ROH), is known to be essential for the process of vision, the immune system but also for cell differentiation and proliferation. Recently, ROH itself has been reported to be involved in adipogenesis and a ROH transport protein, the retinol-binding protein 4 (RBP4), in insulin resistance and type 2 diabetes. However, there is still considerable scientific debate about this relation. With the increasing amount of studies investigating the relation of ROH in obesity and type 2 diabetes, basic research is an essential prerequisite for interpreting these results. This thesis enhances the knowledge on this relation by reviewing ROH metabolism on extra- and intracellular level. Aim 1: In the blood stream ROH is transported in a complex with RBP4 and a second protein, transthyretin (TTR), to the target cells. The levels of RBP4 and TTR are influenced by several factors but mainly by liver and kidney function. The reason for that is that liver and the kidneys are the sites of RBP4 synthesis and catabolism, respectively. Interestingly, obesity and type 2 diabetes involve disorders of the liver and the kidneys. Therefore the aim was to investigate factors that influence RBP4 and TTR levels in relation to obesity and type 2 diabetes (Part 1). Aim 2: Once arrived in the target cell ROH is bound to cellular retinol-binding protein type I (CRBP-I) and metabolised: ROH can either be stored as retinylesters or it can be oxidised to retinoic acid (RA). By acting as a transcription factor in the nucleus RA may influence processes such as adipogenesis. Therefore vitamin A has been postulated to be involved in obesity and type 2 diabetes. CRBP-I is known to mediate the storage of ROH in the liver, but the extra-hepatic metabolism and the functions of CRBP-I are not well known. This has been investigated in Part 2 of this work. Material & Methods: RBP4 and TTR levels were investigated by ELISA in serum samples of human subjects with overweight, type 2 diabetes, kidney or liver dysfunction. Molecular alterations of the RBP4 and TTR protein structure were analysed by MALDI-TOF mass spectrometry. The functions of intracellular CRBP-I were investigated in CRBP-I knock-out mice in liver and extra-hepatic tissues by measuring ROH levels as well as the levels of its storage form, the retinylesters, using reverse phase HPLC. The postprandial uptake of ROH into tissues was analysed using labelled ROH. The mRNA levels of enzymes that metabolize ROH were examined by real-time polymerase chain reaction (RCR). Results: The previous published results showing increased RBP4 levels in type 2 diabetic patients could not be confirmed in this work. However, it could be shown that during kidney dysfunction RBP4 levels are increased and that RBP4 and TTR levels are decreased during liver dysfunction. The important new finding of this work is that increased RBP4 levels in type 2 diabetic mice were increased when kidney function was decreased. Thus an increase in RBP4 levels in type 2 diabetes may be the effect of a reduced kidney function which is common in type 2 diabetes. Interestingly, during severe kidney dysfunction the molecular structure of RBP4 and TTR was altered in a specific manner which was not the case during liver diseases and type 2 diabetes. This underlines the important function of the kidneys in RBP4 metabolism. CRBP-I has been confirmed to be responsible for the ROH storage in the liver since CRBP-I knock-out mice had decreased ROH and retinylesters (the storage form of ROH) levels in the liver. Interestingly, in the adipose tissue (the second largest ROH storage tissue in the body) ROH and retinylesters levels were higher in the CRBP-I knock-out compared to the wild-type mice. It could be shown in this work that a different ROH binding protein, cellular retinol-binding protein type III, is upregulated in CRBP-I knock-out mice. Moreover enzymes were identified which mediate very efficiently ROH esterification in the adipose tissue of the knock-out mice. In the pancreas there was a higher postprandial ROH uptake in the CRBP-I knock-out compard to wild-type mice. Even under a vitamin A deficient diet the knock-out animals had ROH and retinylesters levels which were comparable to wild-type animals. These results underline the important role of ROH for insulin secretion in the pancreas. Summing up, there is evidence that RBP4 levels are more determined by kidney function than by type 2 diabetes and that specific molecular modifications occur during kidney dysfunction. The results in adipose tissue and pancreas of CRBP-I knock-out mice support the hypothesis that ROH plays an important role in glucose and lipid metabolism. / Vitamin A gehört zur Gruppe der fettlöslichen Vitamine und wird chemisch als Retinol bezeichnet. Es ist essentiell für den Prozess des Sehvorgangs und der Zelldifferenzierung und kann daher bestimmte Entwicklungsprozesse wie die Bildung des Fettgewebes beeinflussen. Aufgrund seiner Fettlöslichkeit muss Retinol im Blut (= extrazellulär) sowie in der Zelle (= intrazellulär) an sogenannte Transport-Moleküle, die Retinol-bindenden Proteine (RBPs) gebunden werden. Die zwei bekanntesten Vertreter der RBPs sind das Retinol-bindende Protein 4 (RBP4) und das intrazelluläre Retinol-bindende Protein Typ I (CRBP-I). RBP4 transportiert Vitamin A im Blut von der Leber zur Zielzelle und zum Abbauorgan für Vitamin A, der Niere. CRBP-I ist in der Leber für die Speicherung von Vitamin A zuständig. In den letzten Jahren wurden neben der Beteiligung des Retinols an der Bildung des Fettgewebes auch Studien veröffentlicht, in denen ein Zusammenhang zwischen erhöhten RBP4-Werte im Blut und Typ-2-Diabetes gezeigt wurde. Bis heute ist der mögliche Zusammenhang zwischen RBP4, CRBP-I und Übergewicht nicht ausreichend erforscht. Im ersten Teil der Arbeit war daher das Ziel, Einflussfaktoren, die zu Veränderungen der RBP4-Werte im Blut führen können, zu untersuchen. Dazu wurden Blutproben von Personen mit Übergewicht und/oder Typ-2-Diabetes und Patienten mit Nierenfunktionsstörungen oder mit Leberfunktionsstörungen analysiert. Es konnte gezeigt werden, dass bereits geringe Nierenfunktionsstörungen zu erhöhten RBP4-Konzentrationen im Blut führten. Bei Typ-2-Diabetikern, die sehr oft an Nierenfunktionsstörungen leiden, war eine Erhöhung der RBP4-Konzentration mit einer Abnahme der Nierenfunktion verbunden. Somit lässt sich zusammenfassen, dass nicht Typ-2-Diabetes sondern vielmehr die dabei auftretenden Nierenfunktionsstörungen zu einer Erhöhung der RBP4-Werte führen. Bei Lebererkrankten konnte ein Absinken der RBP4-Werte nachgewiesen werden, was der verminderten Bildung von RBP4 in der Leber bei diesen Patienten zuzuschreiben ist. Im zweiten Teil sollte der Frage nachgegangen werden, wie Retinol intrazellulär verstoffwechselt wird. Dabei lag der Fokus auf der Erforschung der bisher nicht bekannten Funktionen von CRBP-I im Fettgewebe und der Bauchspeicheldrüse. Zur Untersuchung der Funktionen von CRBP-I wurden Mäuse gezüchtet, bei denen das Gen für CRBP-I gelöscht wurde. Da CRBP-I für die Speicherung von Vitamin A in der Leber verantwortlich ist, zeigen diese Mäuse sehr geringe Vitamin-A-Speicher in der Leber. Das gleiche zeigte sich für die Bauchspeicheldrüse, die für die Sekretion von Insulin Vitamin A benötigt: In den Mäusen ohne CRBP-I waren die Retinol-Werte drastisch gesunken. Interessanterweise zeigte sich im Fettgewebe ein gegenteiliges Bild: Die Konzentrationen an Retinol und dessen Speicher waren in den Mäusen ohne CRBP-I höher im Vergleich zu den normalen Mäusen. Mit bestimmten Nachweismethoden konnte herausgefunden werden, dass Retinol im Fettgewebe an ein anderes RBP, das CRBP-III, gebunden wird und dadurch effektiver gespeichert werden kann als durch CRBP-I.

Made available in DSpace on 2014-06-12T23:03:23Z (GMT). No. of bitstreams: 2 arquivo8761_1.pdf: 714218 bytes, checksum: d20a16bb335ecdf9b608fa2fd54b1c1f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / O leite humano muda a sua composição ao longo da lactação, enquanto aumenta o teor de lipídeos decresce o de vitaminas lipossolúveis, se diferenciando basicamente em três fases distintas: colostro, transição e maduro. O desenvolvimento fisiológico da mãe e sua alimentação comprometem a composição e a qualidade do leite, desta forma, estratificou-se as mães em primíparas e multíparas. Este trabalho teve como objetivo de mensurar as variações de vitaminas A e E no leite de diferentes fases, bem como avaliar a influência da dieta nos níveis destas vitaminas e sua adequação nutricional à dieta do lactente. Tomou-se amostras de leite humano de mães primíparas (n=9) e multíparas (n=9), doadoras dos Bancos de leite humano do Recife. Foi levantado inquérito alimentar das mães previamente selecionadas. A extração das vitaminas A (retinoltrans) e E ( -tocoferol) foram obtidas por extração líquido-líquido, após saponificação metanólica, conforme método proposto por Paixão & Stamford (2002); Paixão & Campos, (2003). A quantificação das vitaminas foi obtida por HPLC (High Performance Liquid Chromatography) em uma corrida cromatográfica de 8.5 minutos, eluidas em metanol, numa coluna ODS-II, 150 mm x 3,2 mm, 5 m, lidas em seus máximos de absorção de 325nm, até 5 min, 292nm, de 5.01 a 8.5 min, respectivamente. As multíparas apresentaram níveis de retinol (334±142&#956;g/dL, 208±122&#956;g/dL, 116±38&#956;g/dL) superiores aos da primíparas (179±57&#956;g/dL, 109±64&#956;g/dL, 89±18&#956;g/dL) para colostro, transição e maduro, respectivamente, diferindo significativamente (p 0,001) entre fases. As multíparas diferiram menos, nos níveis de tocoferol, nas fases colostro (1335±906&#956;g/dL) e transição (367±98&#956;g/dL), enquanto no maduro (412±82&#956;g/dL) foi ligeiramente superior, inclusive de modo significante (p 0,001). Ao longo da lactação no período avaliado, o percentual de redução entre as fases, colostro e transição, e colostro e maduro foi mais acentuado para o tocoferol, superiores a 60% em ambos os grupos. A redução mais expressiva de retinol foi obtida entre o leite colostro e maduro (~50%). Na avaliação do inquérito alimentar, observouse o baixo consumo de alimentos ricos em vitamina A, principalmente nas primíparas, e elevado consumo de alimentos ricos em vitamina E em ambos grupos. Existem diferenças nos níveis de retinol e tocoferol entre leite materno de primíparas e multíparas, nas distintas fases. Do leite colostro a maduro, observou-se uma redução nos teores bem como em variabilidade, justificando diferenças no material biológico e tendendo a estabilização no leite maduro

Se ha abordado el estudio detallado de la localización de distintas formas de alcohol deshidrogenasa (ADH) en tejidos de rata y, en particular, en el sistema vascular, tracto gastrointestinal, sistema nervioso central y tejidos oculares. Se han estudiado esencialmente ADH1 y ADH4, que son los enzimas más relevantes en la oxidación de etanol a acetaldehído, y en la oxidación de retinol a retinal en la vía de síntesis del ácido retinoico.ADH4 se detectó como la forma principal en los vasos sanguíneos de la rata, mientras que en los vasos humanos ADH1B era el enzima predominante. Tanto ADH1 como ADH4, se han detectado a lo largo de todo el tracto gastrointestinal, principalmente en la mucosa, variando su cantidad relativa y su ubicación celular en función del área estudiada. ADH4 es más abundante en las partes más externas del tracto (boca, esófago, colon y recto), mientras que ADH1 es la forma mayoritaria en el intestino. En el cerebro, mediante hibridación in situ, ambas formas de ADH se han localizado en el cerebelo, formación hipocampal y áreas muy concretas de la corteza cerebral, mostrando colocalización en algunos tipos celulares y una expresión específica en otros. La inmunodetección de ADH4 en homogeneizados de diferentes regiones cerebrales ha confirmado la presencia de la proteína en áreas concretas del SNC donde también se ha localizado su mRNA. Ambas clases han sido también detectadas en el sistema ventricular y vascular asociado al SNC. En los tejidos oculares, la proteína ADH4 se ha localizado en la coroides, cuerpo ciliar, nervio óptico y en capas concretas de la córnea y retina.Finalmente, se ha comparado el patrón de expresión ADH en tejido hepático con el de una línea celular de hepatocarcinoma. La línea de hepatocarcinoma de rata H4IIEC3 mostró la expresión de ADH1 y ADH3, presentes en hígado normal, y, además, ADH4, ausente en hígado. Se investigó el efecto del ácido retinoico sobre la expresión de cada una de las tres formas de ADH. Se ha observado un aumento de los niveles de mRNA de ADH1 y un descenso de los de ADH4, mientras que los niveles de mRNA de ADH3 se mantuvieron constantes.La distribución de ADH1 y ADH4, junto con sus propiedades cinéticas y su regulación, permiten inferir algunas de sus funciones fisiológicas en el metabolismo del etanol y de los retinoides, la reducción de aldehídos citotóxicos derivados de la peroxidación lipídica, el catabolismo de las catecolaminas, etc. Asimismo, el metabolismo endógeno de etanol, proporciona una base molecular para comprender las alteraciones causadas por el abuso del alcohol en determinados órganos y tejidos. En este sentido, proponemos la hipótesis de que algunos de los efectos tóxicos del etanol podrían explicarse por la interferencia, a nivel de la ADH, con la vía de síntesis del ácido retinoico.

L'àcid retinoic, en les seves formes tot-trans- i 9-cis-, actua com a lligand de receptors nuclears específics, i és essencial en processos de creixement, desenvolupament i manteniment epitelial. La via de formació de l'àcid retinoic inclou dos pasos d'oxidació, de retinol a retinal i de retinal a àcid retinoic. S'han descrit diversos enzims que poden participar en el primer pas, com les ADH i les RDH, però es desconeix la contribució de cada enzim en el procés.S'han clonat, expressat i purificat ADH1B1, ADH2B2 i ADH4 humanes, i també ADH1 i ADH4 de ratolí que, per primera vegada, s'han caracteritzat en la seva forma recombinant. S'han determinat les constants cinètiques de totes aquestes ADHs amb tot-trans- i 7-cis-, 9-cis-, 11-cis- i 13-cis-retinol i els corresponents retinals. En general, les ADH4 humana i de ratolí mostren constants cinètiques similars, i són més eficients que les ADH1. Totes les ADHs utilitzen com a substrats tant 11-cis-retinol com 11-cis-retinal, compostos rellevants en el cicle visual. S'ha observat que l'ADH4 mostra especificitat per a l'oxidació d'11-cis-retinol sobre la reducció d'11-cis-retinal, una propietat única entre totes les ADHs per a qualsevol parella de substrats alcohol/aldehid. Mitjançant mètodes de simulació molecular, i clonatge, expressió i caracterització del mutant de l'ADH4 humana M141L, hem demostrat que el residu 141, situat a la regió mitjana del túnel hidrofòbic del seti actiu de l'ADH, és essencial per definir aquesta especificitat de l'ADH4 sobre les ADH1. La immunolocalització de l'ADH4 a l'epiteli pigmentat i en moltes capes de la retina, dóna suport a la participació de l'ADH4 en diferents reaccions amb retinoides. L'activitat citosòlica de l'ADH4 en l'epiteli pigmentat pot ser complementària a l'activitat 11-cis-retinol deshidrogenasa de la RDH5, necessària per completar el cicle visual, i pot estar també implicada en la generació d'àcid retinoic a les capes neuronals de la retina.Una altra família de retinoides està constituïda per derivats oxidats en l'anell ciclohexè, com per exemple els 4-oxo-, 4-hidroxi- i 3,4-dideshidroretinol i els corresponents retinals. Tot i que són compostos poc estudiats, es coneix que alguns derivats, com els àcids 4-oxo- i el 3,4-dideshidroretinoic poden interaccionar amb receptors nuclears. Les cinètiques dels enzims ADH1B1, ADH2B2 i ADH4 humanes, i també ADH1 i ADH4 de ratolí, indiquen que el 4-oxo-retinal i el 4-hidroxi-retinol són els substrats amb una eficiència catalítica més alta d'entre tots els retinoides, especialment pel que fa a les ADH4, mentre que els 3,4-dideshidroretinoides presenten una activitat similar a la dels tot-trans-retinoides. Les dades obtingudes in vitro recolzen l'existència d'una via metabòlica per a la formació dels àcids retinoics oxidats en l'anell a partir dels corresponents retinols, amb la participació de l'ADH. Finalment, hem comprovat que la presència de Tween 80 provoca una disminució de l'activitat que resulta en una aparent inhibició competitiva en les cinètiques de l'ADH per al tot-trans-retinol, amb un augment de la Km i disminució de l'eficiència catalítica en augmentar la concentració del detergent. Això implica que els valors reals de Km són molt inferiors als publicats fins ara, tradicionalment obtinguts en presència de 0,02 % de Tween 80. Així, les ADHs presenten valors de Km pròxims als de les RDHs i, per tant, la contribució al metabolisme dels retinoides podria ser similar per a ambdós sistemes enzimàtics. Hem comprovat, espectrofotomètricament i per HPLC, que el Tween 80 manté l'estabilitat de la solució aquosa de retinoides, i que permet obtenir resultats reproduïbles i comparables entre diferents ADHs. / Studies in knockout mice support the involvement of alcohol dehydrogenases ADH1 and ADH4 in retinoid metabolism, although kinetics with retinoids are not known for the mouse enzymes. Moreover, a role of ADH in the eye retinoid interconversions cannot be ascertained due to the lack of information on the kinetics with 11-cis-retinoids. We report here the kinetics of human ADH1B1, ADH1B2, ADH4, and mouse ADH1 and ADH4 with all-trans-, 7-cis-, 9-cis-, 11-cis-, and 13-cis-isomers of retinol and retinal. These retinoids are substrates for all enzymes tested, except the 13-cis isomers which are not used by ADH1. In general human and mouse ADH4 exhibit similar activity, higher than that of ADH1, while mouse ADH1 is more efficient than the homologous human enzymes. All tested ADHs use 11-cis-retinoids efficiently. ADH4 shows much higher kcat/Km values for 11-cis-retinol oxidation than for 11-cis-retinal reduction, a unique property among mammalian ADHs for any alcohol/aldehyde substrate pair. Docking simulations and the kinetic properties of the human ADH4 M141L mutant demonstrated that residue 141, in the middle region of the active site, is essential for such ADH4 specificity. The distinct kinetics of ADH4 with 11-cis-retinol, its wide specificity with retinol isomers and its immunolocalization in several retinal cell layers, including pigment epithelium, support a role of this enzyme in the various retinol oxidations that occur in retina. Cytosolic ADH4 activity may complement the isomer-specific microsomal enzymes involved in photopigment regeneration and retinoic acid synthesis.On the other hand, alcohol dehydrogenases (ADH1 and ADH4) actively use retinoids oxidized at the cyclohexenyl ring (4-oxo-, 4-hydroxy- and 3,4-didehydro-retinoids), which are functional compounds in several cells and tissues (i.e. in human skin). Remarkably, activities with 4-oxo-retinal and 4-hydroxy-retinol (kcat = 2050 min-1 for ADH4) are the highest among retinoids, similar to those of the best aliphatic alcohols. Thus, ADH1 and ADH4 provide a metabolic pathway for the synthesis of the corresponding retinoic acids.Finally, Tween 80, a widely used detergent in the retinoid activity assay, behaves as a competitive inhibitor. The Km values for all-trans-retinol (2-3 &#61549;M), estimated in the absence of detergent, are 10-fold lower than those obtained at the usual 0.02% Tween 80. This suggests a contribution of ADH in retinoid metabolism more relevant than previously expected. However, Tween 80 stabilizes retinoids in water solution and provides a reliable and reproducible assay, suitable for comparing different ADHs and different retinoid substrates.

Thesis (M.Sc. (Biochemistry)) -- Mahidol University, 1978. / Supported by the University Development Commission and National Research Council.

Made available in DSpace on 2014-06-12T22:57:38Z (GMT). No. of bitstreams: 2 arquivo3042_1.pdf: 1325924 bytes, checksum: bba8a3182abadb03ffcfe05f5ea44b8e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / O estudo teve como objetivos avaliar o impacto da suplementação oral com dupla megadose de vitamina A (400.000 UI) nas concentrações de retinol sérico de puérperas durante os seis primeiros meses pós-parto bem como descrever a freqüência de deficiência de retinol sérico nas mulheres antes da suplementação de vitamina A. Trata-se de um ensaio clínico randomizado, controlado, triplo-cego, de base hospitalar, com 312 mulheres atendidas no período pós-parto imediato e acompanhadas durante os seis primeiros meses, de dois serviços públicos de saúde na cidade do Recife, região nordeste do Brasil, no período de agosto de 2007 a março de 2009. Todas as mulheres receberam uma cápsula contendo 200.000 UI de vitamina A no pós-parto imediato e no 10º dia foram randomizadas em dois grupos de suplementação: um grupo recebeu uma segunda cápsula de vitamina A (200.000UI) e o outro grupo recebeu o placebo de vitamina A. Além dos dados socioeconômicos, demográficos, antropométricos, clínicos e obstétricos foram coletadas amostras de sangue para as análises das concentrações de retinol sérico, PCR e hemoglobina. A pesquisa foi registrada sob o número NCT00742937. 215 mulheres completaram o estudo (111 no grupo de 400.000 UI de vitamina A e 104 no grupo de 200.000 UI de vitamina A). Não foi observado nenhum evento adverso com a administração das cápsulas de vitamina A. Não houve diferença estatisticamente significante nas concentrações de retinol sérico entre os grupos de suplementação aos 2 meses (2,13 vs 2,03 mmol/L), 4 meses (2,20 vs 2,24 mmol/L) e 6 meses (2,29 vs 2,31 mmol/L). Observou-se um declínio da prevalência de concentrações inadequadas de retinol sérico de 21,1% para 2,35% ao longo dos seis meses após a suplementação. A associação das concentrações de retinol sérico com as variáveis independentes foi testada pela Razão de Prevalência e apenas o número de gestações apresentou associação estatisticamente significante com a deficiência de vitamina A (DVA). Os resultados revelam elevada prevalência concentrações inadequadas de retinol sérico na população estudada, apontando a necessidade de desenvolver ações voltadas para a promoção da educação nutricional além da realização de estudos populacionais para confirmar os fatores de risco que contribuem para o desenvolvimento da DVA. Considerando nenhum efeito adicional observado e que a população estudada tem um nível de deficiência de vitamina A considerada leve,nossos resultados reforçam a manutenção da estratégia de prevenção preconizada pela OMS