scholarly journals Can Increased Vegetable Consumption Improve Iron Status?

1996 ◽  
Vol 17 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Saskia de Pee ◽  
Clive E. West ◽  
Muhilal ◽  
Darwin Karyadi ◽  
Joseph G. A. J. Hautvast
Keyword(s):  
Vitamin A ◽  
Intervention Studies ◽  
Vegetable Consumption ◽  
Iron Status ◽  
Provitamin A ◽  
Review Of The Literature ◽  
Fortified Foods ◽  
Plant Foods ◽  
Provitamin A Carotenoids ◽  
Vitamin A Status

Theoretically, vegetable consumption could improve iron status. First, vegetables contain iron. Second, when the provitamin A carotenoids in vegetables improve vitamin A status, the result could be increased iron levels. Most studies on vegetable consumption have focused on improvements in vitamin A status, and only very few have addressed iron status. From a review of the literature and a recent study in Indonesia, we conclude that the data on the effectiveness of vegetables to improve the levels of both nutrients are inconclusive. The bioavailability of both iron and provitamin A carotenoids might be lower than expected. It is necessary to conduct other intervention studies using plant foods, animal foods, and fortified foods. In the meantime, other strategies that have been proved to reduce iron and vitamin A deficiencies should continue.

Vitamin A Value of Plant Food Provitamin A - Evaluated by the Stable Isotope Technologies

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang
Keyword(s):  
Stable Isotope ◽  
Vitamin A ◽  
Provitamin A ◽  
Animal Origin ◽  
Plant Food ◽  
Plant Foods ◽  
A Value ◽  
Provitamin A Carotenoids ◽  
Β Carotene

Humans need vitamin A and obtain essential vitamin A by conversion of plant foods rich in provitamin A and/or absorption of preformed vitamin A from foods of animal origin. The determination of the vitamin A value of plant foods rich in provitamin A is important but has challenges. The aim of this paper is to review the progress over last 80 years following the discovery on the conversion of β-carotene to vitamin A and the various techniques including stable isotope technologies that have been developed to determine vitamin A values of plant provitamin A (mainly β-carotene). These include applications from using radioactive β-carotene and vitamin A, depletion-repletion with vitamin A and β-carotene, and measuring postprandial chylomicron fractions after feeding a β-carotene rich diet, to using stable isotopes as tracers to follow the absorption and conversion of plant food provitamin A carotenoids (mainly β-carotene) in humans. These approaches have greatly promoted our understanding of the absorption and conversion of β-carotene to vitamin A. Stable isotope labeled plant foods are useful for determining the overall bioavailability of provitamin A carotenoids from specific foods. Locally obtained plant foods can provide vitamin A and prevent deficiency of vitamin A, a remaining worldwide concern.

Identification of Enzymatic Cleavage Products of β-Carotene-Rich Extracts of Kale and Biofortified Maize

2017 ◽  
Vol 87 (5-6) ◽  
pp. 279-286
Author(s):  
Tawanda Muzhingi ◽  
Kyung-Jin Yeum ◽  
Andrew H. Siwela ◽  
Odilia Bermudez ◽  
Guangwen Tang
Keyword(s):  
Vitamin A ◽  
Intestinal Mucosa ◽  
Provitamin A ◽  
Enzymatic Cleavage ◽  
Plant Food ◽  
Plant Foods ◽  
Provitamin A Carotenoids ◽  
Mitochondrial Fractions ◽  
Β Carotene

Abstract. Provitamin A carotenoids in plant foods provide more than 80% of vitamin A intake for people in developing countries. Therefore, the conversion efficiency of β-carotene to vitamin A is important, as it determines the effectiveness of plant foods as sources of vitamin A in humans. The objective of this study was to determine the effect of plant food antioxidants such as α-tocopherol, γ-tocopherol, α-tocotrienol, γ-tocotrienol and total γ-oryzanol on the cleavage of β-carotene in vitro. Rat intestinal mucosa post mitochondrial fractions were incubated with β-carotene-rich extracts of kale and biofortified maize for an hour at 37°C. Rat intestinal mucosa post mitochondrial fractions were also incubated with β-carotene in the presence of either α-tocopherol, γ-tocopherol, α-tocotrienol, γ-tocotrienol or γ-oryzanol for 60 min at 37°C. The β-carotene cleavage products were extracted and analyzed by an HPLC equipped with a C18 column at 340nm and 450nm. When β-carotene alone was incubated without intestinal mucosa homogenate (control), no cleavage products were detected. When β-carotene alone was incubated with intestinal mucosa homogenate, β-apo-13-carotenone, β-apo-14-carotenal, retinal, retinol and retinoic acid were formed. However, incubation of β-carotene with either α-tocopherol, γ-tocopherol or α-tocotrienol resulted in a 10 fold inhibition of β-apo-14-carotenal and β-apo-13-carotenone formation. Antioxidant rich biofortified maize extract incubated with postmitochondrial fraction produced less β-apo-13-carotenone compared to the kale extract. These results suggest that antioxidants inhibit the cleavage of β-carotene and the formation of excentric cleavage products (β-apo-13-carotenone, β-apo-14-carotenal).

scholarly journals Small quantities of carotenoid-rich tropical green leafy vegetables indigenous to Africa maintain vitamin A status in Mongolian gerbils (Meriones unguiculatus)

2010 ◽  
Vol 103 (11) ◽  
pp. 1594-1601 ◽  
Author(s):  
Richard A. Ejoh ◽  
Joseph T. Dever ◽  
Jordan P. Mills ◽  
Sherry A. Tanumihardjo
Keyword(s):  
Vitamin A ◽  
Hibiscus Cannabinus ◽  
Leafy Vegetables ◽  
Provitamin A ◽  
Control Group ◽  
Mongolian Gerbils ◽  
Retinyl Acetate ◽  
Provitamin A Carotenoids ◽  
Vitamin A Status ◽  
Β Carotene

Leafy vegetables are important sources of provitamin A carotenoids. Information on their ability to provide vitamin A is often misleading because of the methodology used to assess bioefficacy. Mongolian gerbils were used to evaluate the bioefficacy of provitamin A carotenoids in tropical leafy vegetables (i.e. Solanum nigrum, Moringa oleifera, Vernonia calvoana and Hibiscus cannabinus) that are indigenous to Africa. Gerbils (n 67) were vitamin A-depleted for 5 weeks. After a baseline kill (n 7), the gerbils were weight-matched and assigned to six treatment groups (n 10; four vegetable groups; negative and positive controls). For 4 weeks, the treatments included 35 nmol vitamin A (theoretical concentrations based on 100 % bioefficacy) in the form of vegetables or retinyl acetate. In addition to their diets, the control and vegetable groups received daily doses of oil, while the vitamin A group received retinyl acetate in oil matched to prior day intake. Serum and livers were analysed for vitamin A using HPLC. Serum retinol concentrations did not differ among groups, but total liver vitamin A of the vitamin A and vegetable groups were higher than that of the negative control group (P < 0·0001). Liver β-carotene 15,15′-monooxygenase-1 expression levels were determined for two vegetable groups and were similar to the positive and negative controls. Conversion factors for the different leafy vegetables were between 1·9 and 2·3 μg β-carotene equivalents to 1 μg retinol. Small quantities of these vegetables maintained vitamin A status in gerbils through efficient bioconversion of β-carotene to retinol.

scholarly journals Our Current Dietary Reference Intakes for Vitamin A—Now 20 Years Old

2020 ◽  
Vol 4 (10) ◽  
Author(s):  
A Catharine Ross ◽  
Nancy E Moran
Keyword(s):  
Vitamin A ◽  
Dark Adaptation ◽  
Interindividual Variability ◽  
Provitamin A ◽  
Future Research ◽  
Vitamin A Metabolism ◽  
Provitamin A Carotenoids ◽  
Dietary Reference Intakes ◽  
Vitamin A Status ◽  
Women And Children

ABSTRACT The DRI values for vitamin A were last reviewed and defined in 2001. At the time, there was very sparse data that could be used to set the DRI values for pregnancy, lactation, and infancy. In the subsequent 20 y since the last formal review, a number of findings relevant to the adequacy indicator of visual dark adaptation in pregnancy, the usual vitamin A content of breast milk across lactation stages, and vitamin A metabolism in women and children have been published. Furthermore, identification of genetic variables affecting the bioconversion of provitamin A carotenoids to vitamin A have provided an improved explanation for interindividual variability in responses to provitamin A carotenoids. The purpose of this collection of articles, introduced herein, is to review and apply recent findings about vitamin A status, address current gaps in knowledge, and suggest avenues for future research needed to refine the DRI values for pregnancy, lactation, and early life.

scholarly journals Content and Retention of Provitamin A Carotenoids Following Ripening and Local Processing of Four Popular Musa Cultivars from Eastern Democratic Republic of Congo

2012 ◽  
Vol 2 (2) ◽  
pp. 60 ◽  
Author(s):  
Beatrice Nakhauka Ekesa ◽  
Judith Kimiywe ◽  
Inge Van den Bergh ◽  
Guy Blomme ◽  
Claudie Dhuique-Mayer ◽  
...  
Keyword(s):  
Vitamin A ◽  
Palm Oil ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Vitamin A Deficiency ◽  
Provitamin A ◽  
Local Processing ◽  
Dietary Intakes ◽  
Republic Of Congo ◽  
Provitamin A Carotenoids

<p>Changes in the concentrations and retention levels of total and individual provitamin A carotenoids (pVACs) during ripening and local processing of the four most popular <em>Musa</em> cultivars of Eastern Democratic Republic of Congo were established through HPLC analysis. The predominant pVACs were all <em>trans</em> ?- and ?-carotene, together constituting about 90% of total pVACs content in raw and processed <em>Musa</em> fruit pulp. The proportion of ?- and ?-carotene was not significantly different in the tested East African Highland Bananas (AAA-EAHB) (‘Nshikazi’ and ‘Vulambya’); in the plantains (‘Musilongo’ and ‘Musheba’), proportion of ?-carotene was almost twice that of ?-carotene. An increase in total pVACs was observed during ripening, with highest levels at ripening stage 3 in all four cultivars. Total pVACs values were as high as 1081µg/100gfw in ‘Vulambya’ and 1819µg/100gfw in ‘Musilongo’. Boiling of the AAA-EAHB and AAB-Plantains resulted to retention of between 40-90% and &gt;95% respectively. Plantains deep-fried in fully-refined palm oil and crude red palm oil for 2 minutes did not seem to lose any pVACs, the levels of total pVACs observed after frying were 100% of what was observed when the fruit was raw. Retinol Activity Equivalents (RAE), in boiled products varied between 22.3 and 173 RAEµg/100gfw, whereas deep fried products had &gt;190 RAEµg/100g edible portion. These results show that the tested AAA-EAHBs and the plantains could meet at least 14% and 30 % of Vitamin A recommended dietary intakes respectively. The findings can therefore guide consumer consumption patterns to maximize vitamin A intake for improved health in these regions and also direct researchers in the selection of <em>Musa</em> cultivars to be incorporated within existing farming systems in the fight against vitamin A deficiency (VAD).</p>

scholarly journals Cassava with enhanced β-carotene maintains adequate vitamin A status in Mongolian gerbils (Meriones unguiculatus) despite substantial cis-isomer content

2009 ◽  
Vol 102 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Julie A. Howe ◽  
Bussie Maziya-Dixon ◽  
Sherry A. Tanumihardjo
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Meriones Unguiculatus ◽  
Provitamin A ◽  
Carotenoid Content ◽  
Mongolian Gerbils ◽  
Serum Retinol ◽  
Vitamin A Status ◽  
Isomer Content ◽  
Β Carotene

Efforts to increase β-carotene in cassava have been successful, but the ability of high-β-carotene cassava to prevent vitamin A deficiency has not been determined. Two studies investigated the bioefficacy of provitamin A in cassava and compared the effects of carotenoid content and variety on vitamin A status in vitamin A-depleted Mongolian gerbils (Meriones unguiculatus). Gerbils were fed a vitamin A-free diet 4 weeks prior to treatment. In Expt 1, treatments (ten gerbils per group) included 45 % high-β-carotene cassava, β-carotene and vitamin A supplements (intake matched to high-β-carotene cassava group), and oil control. In Expt 2, gerbils were fed cassava feeds with 1·8 or 4·3 nmol provitamin A/g prepared with two varieties. Gerbils were killed after 4 weeks. For Expt 1, liver vitamin A was higher (P < 0·05) in the vitamin A (1·45 (sd 0·23) μmol/liver), lower in the control (0·43 (sd 0·10) μmol/liver), but did not differ from the β-carotene group (0·77 (sd 0·12) μmol/liver) when compared with the high-β-carotene cassava group (0·69 (sd 0·20) μmol/liver). The bioconversion factor was 3·7 μg β-carotene to 1 μg retinol (2 mol:1 mol), despite 48 % cis-β-carotene [(Z)-β-carotene] composition in cassava. In Expt 2, cassava feed with 4·3 nmol provitamin A/g maintained vitamin A status. No effect of cassava variety was observed. Serum retinol concentrations did not differ. β-Carotene was detected in livers of gerbils receiving cassava and supplements, but the cis-to-trans ratio in liver differed from intake. Biofortified cassava adequately maintained vitamin A status and was as efficacious as β-carotene supplementation in the gerbil model.

scholarly journals Maize meal fortification is associated with improved vitamin A and iron status in adolescents and reduced childhood anaemia in a food aid-dependent refugee population

2008 ◽  
Vol 11 (7) ◽  
pp. 720-728 ◽  
Author(s):  
Andrew Seal ◽  
Emmanuel Kafwembe ◽  
Ismail AR Kassim ◽  
Mei Hong ◽  
Annie Wesley ◽  
...  
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Iron Status ◽  
Household Survey ◽  
Refugee Camp ◽  
Food Aid ◽  
Serum Retinol ◽  
Post Intervention ◽  
Vitamin A Status ◽  
Maize Meal

AbstractObjectiveTo assess changes in the Fe and vitamin A status of the population of Nangweshi refugee camp associated with the introduction of maize meal fortification.DesignPre- and post-intervention study using a longitudinal cohort.SettingNangweshi refugee camp, Zambia.SubjectsTwo hundred and twelve adolescents (10–19 years), 157 children (6–59 months) and 118 women (20–49 years) were selected at random by household survey in July 2003 and followed up after 12 months.ResultsMaize grain was milled and fortified in two custom-designed mills installed at a central location in the camp and a daily ration of 400 g per person was distributed twice monthly to households as part of the routine food aid ration. During the intervention period mean Hb increased in children (0·87 g/dl;P< 0·001) and adolescents (0·24 g/dl;P= 0·043) but did not increase in women. Anaemia decreased in children by 23·4 % (P< 0·001) but there was no significant change in adolescents or women. Serum transferrin receptor (log10-transformed) decreased by −0·082 μg/ml (P= 0·036) indicating an improvement in the Fe status of adolescents but there was no significant decrease in the prevalence of deficiency (−8·5 %;P= 0·079). In adolescents, serum retinol increased by 0·16 μmol/l (P< 0·001) and vitamin A deficiency decreased by 26·1 % (P< 0·001).ConclusionsThe introduction of fortified maize meal led to a decrease in anaemia in children and a decrease in vitamin A deficiency in adolescents. Centralised, camp-level milling and fortification of maize meal is a feasible and pertinent intervention in food aid operations.

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