Use of Stable Isotopes to Evaluate Bioefficacy of Provitamin A Carotenoids, Vitamin A Status, and Bioavailability of Iron and Zinc

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.

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

British Journal Of Nutrition ◽

10.1017/s0007114509993588 ◽

2010 ◽

Vol 103 (11) ◽

pp. 1594-1601 ◽

Cited By ~ 9

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.

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

Current Developments in Nutrition ◽

10.1093/cdn/nzaa096 ◽

2020 ◽

Vol 4 (10) ◽

Cited By ~ 1

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.

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The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet

Journal of Nutritional Science and Vitaminology ◽

10.3177/jnsv.61.205 ◽

2015 ◽

Vol 61 (3) ◽

pp. 205-214 ◽

Cited By ~ 9

Author(s):

Marie Modestine KANA-SOP ◽

Inocent GOUADO ◽

Mercy Bih ACHU ◽

John VAN CAMP ◽

Paul Henri AMVAM ZOLLO ◽

...

Keyword(s):

Vitamin A ◽

Zinc Supplementation ◽

Provitamin A ◽

Deficient Diet ◽

Provitamin A Carotenoids ◽

Iron And Zinc

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

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000183 ◽

2014 ◽

Vol 84 (Supplement 1) ◽

pp. 25-29 ◽

Cited By ~ 7

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.

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Vitamin A and the provitamin A carotenoids

Bioavailability and Analysis of Vitamins in Foods ◽

10.1007/978-1-4899-3414-7_3 ◽

1998 ◽

pp. 115-161

Author(s):

G. F. M. Ball

Keyword(s):

Vitamin A ◽

Provitamin A ◽

Provitamin A Carotenoids

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

Sustainable Agriculture Research ◽

10.5539/sar.v2n2p60 ◽

2012 ◽

Vol 2 (2) ◽

pp. 60 ◽

Cited By ~ 7

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

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 Musa cultivars of Eastern Democratic Republic of Congo were established through HPLC analysis. The predominant pVACs were all trans ?- and ?-carotene, together constituting about 90% of total pVACs content in raw and processed Musa 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 >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 >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 Musa cultivars to be incorporated within existing farming systems in the fight against vitamin A deficiency (VAD).

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

British Journal Of Nutrition ◽

10.1017/s0007114508184720 ◽

2009 ◽

Vol 102 (3) ◽

pp. 342-349 ◽

Cited By ~ 25

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.

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Caregiver Perceptions and Acceptability of a Provitamin A Carotenoid, Iron and Zinc Rich Complementary Food Blend Prepared from Common Bean and Pumpkin in Rural Uganda

Nutrients ◽

10.3390/nu12040906 ◽

2020 ◽

Vol 12 (4) ◽

pp. 906 ◽

Cited By ~ 1

Author(s):

Edward Buzigi ◽

Kirthee Pillay ◽

Muthulisi Siwela

Keyword(s):

Vitamin A ◽

Common Bean ◽

Vitamin A Deficiency ◽

Sensory Attributes ◽

Provitamin A ◽

Complementary Food ◽

Chi Square ◽

Significant Difference ◽

Iron And Zinc ◽

Chi Square Test

Ugandan children are vulnerable to vitamin A deficiency (VAD), iron deficiency (ID) and zinc deficiency (ZnD) because they are fed on complementary foods (CFs) low in vitamin A, iron and zinc. This study developed a novel provitamin A carotenoid (PVAC), iron and zinc rich common bean pumpkin blend (BPB) complementary food (CF) from locally available pumpkin and common bean in Uganda and aimed to determine its acceptance, compared to a control pumpkin blend (PB). Seventy caregivers participated in the study. The sensory attributes (taste, colour, aroma, texture and general acceptability) of BPB and PB were rated using a five-point facial hedonic scale (1 = very bad, 2 = bad, 3 = neutral, 4 = good, 5 = very good). Focus group discussions (FGDs) were conducted to assess the perceptions of caregivers about the BPB. The chi square test was used to detect the proportion difference for each sensory attribute between BPB and PB, whilst FGD data were analysed by thematic analysis. A proportion of 64% to 96% of the caregivers rated both BPB and PB as acceptable (good to very good) for all the sensory attributes. There was no significant difference in caregiver acceptability for all attributes between BPB and PB (p > 0.05). Caregivers had positive perceptions about the taste, texture, aroma and colour of the BPB. Caregivers were keen to know the specific varieties of common bean and pumpkin used to formulate the PVAC, iron and zinc rich BPB. In conclusion, BPB was acceptable to caregivers, and they were interested to know how to prepare and use it as a CF.

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Fortification of Sugar with Vitamin A

Food and Nutrition Bulletin ◽

10.1177/156482659801900207 ◽

1998 ◽

Vol 19 (2) ◽

pp. 131-136 ◽

Cited By ~ 8

Author(s):

Oscar Pineda

Keyword(s):

Vitamin A ◽

Latin American ◽

Sugar Industry ◽

Central American ◽

Vitamin A Status ◽

Organoleptic Characteristics ◽

Iron And Zinc ◽

Dry Mixing ◽

Colour Changes ◽

Two Stages

The technology for fortifying sugar with vitamin A was developed in Guatemala in the mid-1970s, and the Guatemalan government enacted legislation to make fortification mandatory in June 1974. This action was copied by other Central American governments. The fortification programme in Guatemala developed in two stages. In the first (1975–77), the fortification programme was evaluated four times at six-month intervals and was shown to be effective. The sugar industry was responsible for carrying out the programme, but the programme was suspended, mainly because of economic arguments. After 10 years of effort, the programme was restarted in 1989. At this time the programme was combined with an initial mass distribution of vitamin A capsules to pre-school children, which began the first successful social mobilization effort in the area. The programme was evaluated for six months and was shown to be effective in improving the vitamin A status of the Guatemalan population. This sec- ond stage has been active continuously since 1989. With improvements in the technology of fortification, new approaches have been tested, and now it is possible to obtain an excellent sugar doubly fortified with vitamin A and iron, using new iron products of high bioavailability that do not alter the organoleptic characteristics of the sugar and do not produce unwanted colour changes during processing. To avoid the rancidity of premixes, new processes of dry mixing have been developed in which no oil is used, This opens a real possibility for the fortification of sugar with other nutrients. Sugar fortified with vitamin A, iron, and zinc, either alone or in any combination, is commercially available in Brazil, where, under the guidance of the Latin American Centre of Nutrition and Metabolic Studies (CELANEM), the procedures have been developed using iron amino acid chelated minerals.

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