scholarly journals Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1703
Author(s):  
Alejandro Carazo ◽  
Kateřina Macáková ◽  
Kateřina Matoušová ◽  
Lenka Kujovská Krčmová ◽  
Michele Protti ◽  
...  

Vitamin A is a group of vital micronutrients widely present in the human diet. Animal-based products are a rich source of the retinyl ester form of the vitamin, while vegetables and fruits contain carotenoids, most of which are provitamin A. Vitamin A plays a key role in the correct functioning of multiple physiological functions. The human organism can metabolize natural forms of vitamin A and provitamin A into biologically active forms (retinol, retinal, retinoic acid), which interact with multiple molecular targets, including nuclear receptors, opsin in the retina and, according to the latest research, also some enzymes. In this review, we aim to provide a complex view on the present knowledge about vitamin A ranging from its sources through its physiological functions to consequences of its deficiency and metabolic fate up to possible pharmacological administration and potential toxicity. Current analytical methods used for its detection in real samples are included as well.

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang

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.


2012 ◽  
Vol 2 (2) ◽  
pp. 60 ◽  
Author(s):  
Beatrice Nakhauka Ekesa ◽  
Judith Kimiywe ◽  
Inge Van den Bergh ◽  
Guy Blomme ◽  
Claudie Dhuique-Mayer ◽  
...  

<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>


2018 ◽  
Vol 7 (2) ◽  
pp. 20-26
Author(s):  
Lyubov Georgievna Demenina ◽  
Anna Borisovna Petrova ◽  
Kristina Andreevna Savitskaya ◽  
Lyudmila Mikhailovna Kavelenova

The paper deals with the peculiarities of the biological characteristics of the most important fruit crops of temperate climates - apple and pear (Rosaceae family, subfamily Maloideae), taking into account the world, national and regional cultivation. Both cultures are characterized by significant food and commodity value, have some differences in the chemical composition of the fruit, including the leading components of the mass and biologically active substances, which determine the peculiarities of their use in the human diet. In both global and national fruit-growing, pears play a secondary role compared to apple, giving way to the number of varieties, the volume of production and the areas occupied. Based on the analysis of available statistical data of the FAO database, the dynamics of changes from 1990 to 2016 of the world production of apple and pear fruits with visualization on the continents, identifying world leaders and major trends are considered. For the USSR (from 1962 to 1990) and in Russian Federation (from 1992 to 2016) the paper presents a picture of changes in the volume of fruit production, discusses the status of fruit production in the country. The features of the historical development and current state of fruit growing in the Samara Region and prospects are discussed.


2017 ◽  
Vol 6 (2) ◽  
pp. 39-44
Author(s):  
Gilian Tetelepta ◽  
Priscillia Picauly

Tongka langit banana contain high nutrients including pro vitamin A and a total of carotene. However, it is also a perishable product, and would deteriorate if not processed or not completely consumed. Therefore, this banana should be processed into diverse products. It can be processed into intermediate product such as flour, which can be further applied in crackers making. This research was conducted in two stages. First stage was the making of tongka langit banana flour and the second was crackers making. The crackers were made from tongka langit banana flour and wheat flour having different ratios, i.e. 20 %: 80 %; 40 %: 60 %; 60 %: 40 %; 80 %: 20 %. Variables observed on crackers including moisture, ash, protein, fat, dietary fiber and carbohydrate contents, as well as organoleptic properties of taste, aroma, colour, texture and overall likeness. Results showed that ratio of banana flour to wheat flour of 40%:60% produced crackers with moisture, ash, protein, fat, fiber, and carbohydrate contents of 4.60%, 4.46%, 6.64%, 17.54%, 1.18% and 4.60%, respectively. In addition, organoleptic test revealed that crackers made from 40% banana flour and 60% wheat flour were mostly liked by panelists in terms of taste, colour, aroma, texture and overall likeness. Keywords: crackers, tongka langit banana   ABSTRAK Pisang tongka langit kaya akan kandungan gizi antara lain mengandung provitamin A dan total karotenoid yang sangat tinggi. Namun pisang tongka langit mudah mengalami kerusakan jika tertunda pengolahannya atau tidak habis dikonsumsi, oleh karena itu perlu dilakukan upaya diversifikasi terhadap pisang tongka langit. Pisang tongka langit dapat diolah menjadi bahan setengah jadi berupa tepung yang dapat diaplikasikan menjadi produk crackers. Penelitian ini dilakukan dalam dua tahap, tahap I adalah pembuatan tepung pisang tongka langit dan tahap II adalah pembuatan crackers dari tepung pisang tongka langit dan tepung terigu dengan empat taraf perlakuan perbandingan subtitusi tepung pisang tongka langit dan tepung terigu yaitu masing-masing 20 %: 80 %; 40 %: 60 %; 60 %: 40 %; 80 %: 20 %. Pengamatan yang dilakukan pada crackers yaitu analisa kadar air, abu, protein, lemak, serat pangan, karbohidrat dan uji organoleptik yang meliputi rasa, aroma, warna, tekstur dan tingkat kesukaan secara keseluruhan. Hasil penelitian menunjukkan bahwa formula crackers tepung pisang tongka langit 40% : 60% memiliki nilai kadar air berkisar antara 4,60%, kadar abu 4,46%, protein 6,64%, lemak 17,54%, serat 1,18% dan karbohidrat 4,60%. Sedangkan uji organoleptik menunjukkan bahwa crackers tepung pisang tongka langit 40% : tepung terigu 60% memiliki rasa, warna, aroma, tekstur dan tingkat penerimaan secara keseluruhan yang disukai panelis. Kata Kunci: crackers, pisang tongka langit


2018 ◽  
Vol 26 (2) ◽  
pp. 296-304
Author(s):  
Elena A. Laksaeva

An interest in plants of Amelanchier genus is stimulated by the necessity of search for plant sources rich in biologically active substances and possessing the ability to influence different physiological processes in a human organism. The article gives information about places of growth of different species of Amelanchier (Amelanchier Medic) and about the fact that its fruits contain high concentration of free sugars, relatively low level of organic acids, sufficient amounts of various vitamins and provitamins and a complex of mineral substances. Nutritive and biological value of Amelanchier fruits in complex may produce a beneficial effect on different biochemical and physiological processes of normal vital activity of a human organism. The data are given about a positive influence of enteral introduction of polysaccharides isolated from Amelanchier fruits, on different physiological processes that enhance adaptational reserves of an organism of experimental animals. In particular, it was shown that watersoluble polysaccharide complex (WSPC) of Amelanchier fruits activates erythropoiesis increasing the amount of erythrocytes and hemoglobin in blood of experimental animals and raises concentration of iron. WSPC improves physical working capacity and increases the body mass of experimental animals. Addition of watersoluble polysaccharide complex of Amelanchier fruits to blood of a healthy donor increases thermal, osmotic and peroxide resistance of erythrocyte membranes thus protecting cells against damage under action of adverse factors in the experiment. Fruits of plants of Amelanchier genus may be recommended to be used as a food additive or a product in dietary and prophylactic therapy.


2009 ◽  
Vol 102 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Julie A. Howe ◽  
Bussie Maziya-Dixon ◽  
Sherry A. Tanumihardjo

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.


2019 ◽  
Vol 93 (8) ◽  
Author(s):  
Bo-Ram Bang ◽  
Meng Li ◽  
Kuen-Nan Tsai ◽  
Haruyo Aoyagi ◽  
Shin-Ae Lee ◽  
...  

ABSTRACTRetinoid (vitamin A) is an essential diet constituent that governs a broad range of biological processes. Its biologically active metabolite, all-transretinoic acid (ATRA), exhibits a potent antiviral property by enhancing both innate and adaptive antiviral immunity against a variety of viral pathogens, such as, but not limited to, HIV, respiratory syncytial virus (RSV), herpes simplex virus (HSV), and measles. Even though the hepatocyte is highly enriched with retinoid and its metabolite ATRA, it supports the establishment of efficient hepatitis C virus (HCV) replication. Here, we demonstrate the hepatocyte-specific cell-intrinsic mechanism by which ATRA exerts either a proviral or antiviral effect, depending on how it engages cellular retinoic acid binding proteins (CRABPs). We found that the engagement of CRABP1 by ATRA potently supported viral infection by promoting the accumulation of lipid droplets (LDs), which robustly enhanced the formation of a replication complex on the LD-associated endoplasmic reticulum (ER) membrane. In contrast, ATRA binding to CRABP2 potently inhibited HCV via suppression of LD accumulation. However, this antiviral effect of CRABP2 was abrogated due to the functional and quantitative predominance of CRABP1 in the hepatocytes. In summary, our study demonstrates that CRABPs serve as an on-off switch that modulates the efficiency of the HCV life cycle and elucidates how HCV evades the antiviral properties of ATRA via the exploitation of CRABP1 functionality.IMPORTANCEATRA, a biologically active metabolite of vitamin A, exerts pleiotropic biological effects, including the activation of both innate and adaptive immunity, thereby serving as a potent antimicrobial compound against numerous viral pathogens. Despite the enrichment of hepatocytes with vitamin A, HCV still establishes an efficient viral life cycle. Here, we discovered that the hepatocellular response to ATRA creates either a proviral or an antiviral environment depending on its engagement with CRABP1 or -2, respectively. CRABP1 supports the robust replication of HCV, while CRABP2 potently inhibits the efficiency of viral replication. Our biochemical, genetic, and microscopic analyses reveal that the pro- and antiviral effects of CRABPs are mediated by modulation of LD abundance, where HCV establishes the platform for viral replication and assembly on the LD-associated ER membrane. This study uncovered a cell-intrinsic mechanism by which HCV exploits the proviral function of CRABP1 to establish an efficient viral life cycle.


Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 906 ◽  
Author(s):  
Edward Buzigi ◽  
Kirthee Pillay ◽  
Muthulisi Siwela

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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