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

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.

Download Full-text

Can Increased Vegetable Consumption Improve Iron Status?

Food and Nutrition Bulletin ◽

10.1177/156482659601700107 ◽

1996 ◽

Vol 17 (1) ◽

pp. 1-3 ◽

Cited By ~ 7

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.

Download Full-text

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.

Download Full-text

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

Advances in Nutrition ◽

10.1093/advances/nmy036 ◽

2018 ◽

Vol 9 (5) ◽

pp. 625-636 ◽

Cited By ~ 4

Author(s):

Jesse Sheftel ◽

Cornelia Loechl ◽

Najat Mokhtar ◽

Sherry A Tanumihardjo

Keyword(s):

Stable Isotopes ◽

Vitamin A ◽

Provitamin A ◽

Provitamin A Carotenoids ◽

Vitamin A Status ◽

Iron And Zinc

Download Full-text

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.

Download Full-text

Potential of pumpkin to combat vitamin A deficiency during complementary feeding in low and middle income countries: variety, provitamin A carotenoid content and retention, and dietary reference intakes

Critical Reviews in Food Science and Nutrition ◽

10.1080/10408398.2021.1896472 ◽

2021 ◽

pp. 1-10

Author(s):

Edward Buzigi ◽

Kirthee Pillay ◽

Muthulisi Siwela

Keyword(s):

Vitamin A ◽

Complementary Feeding ◽

Vitamin A Deficiency ◽

Provitamin A ◽

Carotenoid Content ◽

Middle Income ◽

Middle Income Countries ◽

Dietary Reference Intakes ◽

Low And Middle Income

Download Full-text

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

Download Full-text

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).

Download Full-text

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.

Download Full-text