Vitamin APub Date : 2019-05-15DOI: 10.5772/INTECHOPEN.84829
V. Uarrota, Angela de Fatima Moreira de Bairros, D. Gindri, L. Leolato, G. C. Andrade, Daniele Nerling, D. Stefen, Mhanuel Arijama, Emílio Henriques Razão, Miguel Rocha
{"title":"From Neglected and Underutilized Crops to Powerful Sources of Vitamin A: Three Case Studies of Mozambican Cultivated Tacca leontopetaloides, Cowpea, and Cassava","authors":"V. Uarrota, Angela de Fatima Moreira de Bairros, D. Gindri, L. Leolato, G. C. Andrade, Daniele Nerling, D. Stefen, Mhanuel Arijama, Emílio Henriques Razão, Miguel Rocha","doi":"10.5772/INTECHOPEN.84829","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.84829","url":null,"abstract":"","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72927744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vitamin APub Date : 2019-05-15DOI: 10.5772/INTECHOPEN.84586
Jody A. Summers
{"title":"Retinoic Acid in Ocular Growth Regulation","authors":"Jody A. Summers","doi":"10.5772/INTECHOPEN.84586","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.84586","url":null,"abstract":"All-trans-retinoic acid (atRA) is a metabolite of vitamin A (retinol) and is required for growth and development of a variety of organ systems in all higher animals from fish to humans. Evidence is accumulating to suggest that atRA may also be an important molecular signal in the postnatal control of eye size. Choroidal synthesis of atRA is modulated during periods of visually-induced changes in ocular growth and has pronounced effects on eye growth and refraction in several animal models of myopia. Choroidal atRA synthesis is exclusively regulated by expression of the enzyme, retinaldehyde dehydrogenase 2 (RALDH2). In chicks and humans, RALDH2 is synthesized by a unique population of uncharacterized extravascular stromal cells concentrated in the proximal choroid. The identification of choroidal atRA and RALDH2 as visually induced ocular growth regulators provides the potential for new therapeutic targets for the treatment of childhood myopia. The objective of this chapter is to discuss what is presently known about atRA biosynthesis and transport in the eye during visually guided eye growth and how this research can contribute to a better understanding of the mechanisms underlying the development of myopia.","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78447701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vitamin APub Date : 2019-04-17DOI: 10.5772/INTECHOPEN.84460
M. F. M. Noh, Rathi Devi-Nair Gunasegavan, Suraiami Mustar
{"title":"Vitamin A in Health and Disease","authors":"M. F. M. Noh, Rathi Devi-Nair Gunasegavan, Suraiami Mustar","doi":"10.5772/INTECHOPEN.84460","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.84460","url":null,"abstract":"Vitamin A refers to a group of related compounds with all-trans retinol biological activity and includes retinol, retinal, retinoic acid as well as the retinyl esters. Dietary source of vitamin A ranges from animal-based or plant-based foods, fortified food products and supplements. The vital biological roles of vitamin A compounds include normal cell growth, cell differentiation, vision and immunology. Vitamin A status is monitored to prevent occurrence of both subclinical deficiency and toxicity. Vitamin deficiency or excess is determined through the measure of vitamin A status. Prolonged vitamin A intake at high doses is shown to be toxic, which leads to various health symptoms. Xerophthalmia, a dry eye condition is the most severe clinical effects known to be caused by vitamin A deficiency. The resulting deleterious effects on human health led to efforts of supplementation, food fortification and dietary diversification in combating vitamin A deficiency. In brief, this chapter covers on vitamin A, with focus on its general information, dietary recommendations, biological roles, vitamin A status assessment, deficiency or excess effects to human health as well as the prevention measures.","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90580236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vitamin APub Date : 2019-03-11DOI: 10.5772/INTECHOPEN.84445
A. Dubock
{"title":"Golden Rice: To Combat Vitamin A Deficiency for Public Health","authors":"A. Dubock","doi":"10.5772/INTECHOPEN.84445","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.84445","url":null,"abstract":"Vitamin A deficiency (VAD) has been recognised as a significant public health problem continuously for more than 30 years, despite current interventions. The problem is particularly severe in populations where rice is the staple food and diversity of diet is limited, as white rice contains no micronutrients. Golden Rice is a public-sector product designed as an additional intervention for VAD. There will be no charge for the nutritional trait, which has been donated by its inventors for use in public-sector rice varieties to assist the resource poor, and no limitations on what small farmers can do with the crop—saving and replanting seed, selling seed and selling grain are all possible. Because Golden Rice had to be created by introducing two new genes—one from maize and the other from a very commonly ingested soil bacterium—it has taken a long time to get from the laboratory to the field. Now it has been formally registered as safe as food, feed, or in processed form by four industrialised counties, and applications are pending in developing countries. The data are summarised here, and criticisms addressed, for a public health professional audience: is it needed, will it work, is it safe and is it economic? Adoption of Golden Rice, the next step after in-country registration, requires strategic and tactical cooperation across professions, non-governmental organisations (NGOs) and government departments often not used to working together. Public health professionals need to play a prominent role.","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74136905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vitamin APub Date : 2019-02-20DOI: 10.5772/INTECHOPEN.84615
T. C. Nascimento, E. Jacob‐Lopes, V. V. Rosso, L. Q. Zepka
{"title":"Introductory Chapter: A Global Perspective on Vitamin A","authors":"T. C. Nascimento, E. Jacob‐Lopes, V. V. Rosso, L. Q. Zepka","doi":"10.5772/INTECHOPEN.84615","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.84615","url":null,"abstract":"Vitamin A is a globally essential nutrient belonging to the group of fat-soluble vitamins that was first described in 1913 in a study of animals fed with ethereal egg or butter extract [1]. In the same year, Osborne and Mendel [2] made the first association of this vitamin with growth. Later, observations made by Steenbock [3] concluded their association with foods of yellow pigmentation (now known as β-carotene). The importance of vitamin A in vision health has been considered since ancient Egypt (1500 BC), where people suffering from night blindness were treated with a topical extract of hepatic liver extract (recognized today as a rich source of vitamin A) [3–6]. Its deficiency has typically been associated with continued malnutrition and childhood blindness; it is estimated that 254 million people suffer from vitamin A lack or related ocular disease [7]. It is now known that its benefits go beyond its role in vision yet include numerous essential metabolic and systemic functions [8]. To supply their metabolic functions and to avoid deficiency or overdosage, daily intake requirements were established according to their activity. This activity can be expressed as international units (IU) or retinol equivalents (RE): 1 IU is equivalent to 0.3 μg of total trans retinol or 0.6 μg of total all-trans-β-carotene, whereas 1 RE is equivalent to 1 μg of all-trans-retinol, 6 μg of all-trans-β-carotene, or 12 μg of another provitamin A carotenoids [9]. The recommended daily requirement for adult men and women is 900 and 700 μg RE/day, respectively, while 300 and 250 μg RE/day are the minimum intake limits. During pregnancy and lactation, recommendations are 700 and 950 μg RE/day, respectively [8, 9]. In the case of children in populations considered vitamin A deficient, doses of 60,000 μg RE/day are distributed twice a year [10]. According to Stephensen et al. [11], acute toxic reactions are uncommon at the dosages below 30,000 μg RE/day.","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85049048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vitamin APub Date : 2018-12-31DOI: 10.5772/INTECHOPEN.83523
I. Okayasu, M. Fujiwara, Tsutomu Yoshida
{"title":"The Role of Vitamin A-Storing Cells (Stellate Cells) in Inflammation and Tumorigenesis","authors":"I. Okayasu, M. Fujiwara, Tsutomu Yoshida","doi":"10.5772/INTECHOPEN.83523","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.83523","url":null,"abstract":"Characteristic localization and distribution of vitamin A-storing cells (stel-late cells) were demonstrated as hepatic stellate cells in the hepatic lobule and as subepithelial myofibroblasts in the colonic crypt. The stem cell-stem cell niche is maintained by stellate cells in the periportal area and crypt base. Periportal vitamin A-rich stellate cells decrease in patients with chronic hepatitis C who are habitual smokers. Mice fed a vitamin A-supplemented diet show reduced severity of dextran sulfate sodium (DSS)-induced colitis and development of subsequent colonic neoplasia in a model of the ulcerative colitis-dysplasia-carcinoma sequence, compared with mice fed a vitamin A-deficient diet. Decreased colonic subepithelial myofibroblasts and IgA/IgG-positive cells, and increased CD11c-positive dendritic cells in the colonic mucosa, in the vitamin A-deficient state suggest dysfunction of the stem cell niche at the colonic crypt base and colonic immunity. Accordingly, vitamin A deficiency may worsen inflammation and subsequent tumor development, indicating the possibility that vitamin A supplementation might be effective against chronic inflammation and cancer development.","PeriodicalId":23500,"journal":{"name":"Vitamin A","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73111370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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