Vitamin A is an essential micronutrient required to maintain vision, the immune response, barrier function, growth and differentiation, male and female reproduction, and fetal development. It is acquired from the diet either as preformed vitamin A from animal foods or as provitamin A carotenoids ...
H. 2012. Mechanisms involved in the intestinal absorption of dietary vitamin A and provitamin A carotenoids. Biochim. Biophys. Acta 1821: 70-77.Harrison E. H. (2012). Mechanisms involved in the intestinal absorption of dietary vitamin A and provitamin A carotenoids . Biochim. Biophys. Acta ...
However, epidemiologic studies of vitamin A, retinol (preformed vitamin A), and provitamin A carotenoids in relation to the risk of gastric cancer have documented inconsistent results. Objective:The objective of the study was to examine the associations between intakes of vitamin A, retinol, and ...
Learn more about VITAMIN A uses, effectiveness, possible side effects, interactions, dosage, user ratings and products that contain VITAMIN A.
Vitamin A is fat-soluble, which means it can accumulate in our body. Large amounts of beta-carotene and other provitamin A carotenoids are not associated with major adverse effects, but preformed vitamin A can have significant toxicity, so it is possible to have too much vitamin A. The symp...
Vitamin A sources and storage Two main dietary forms of vitamin A exist: pre-formed vitamin A, found in foods such as butter, egg yolks and cod-liver oil, and provitamin A carotenoids, found in foods such as spinach, carrots, mangoes and papayas. Approximately 90% of the vitamin A in ...
Your body absorbs preformed vitamin A much more efficiently than provitamin A carotenoids. For example, between 70-90% of preformed vitamin A from supplements are absorbed in the digestive tract compared to 8.7-65% of beta-carotene.1 Because of this significant difference, recommended intake levels...
Vitamin A is a class of versatile nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids, all of which are necessary for growth and development, immune system function, and good vision. Retinol is necessary for good vision, especially at ...
FROM DIETARY VITAMIN A TO CIRCULATING SERUM RETINOL The precursors of atRA have to be obtained from the diet, either as retinyl esters from animal sources or provitamin A carotenoids from plants, mainly as β-carotene (reviewed in Refs. 15 and 16, and in this thematic series by Harrison and...
Mechanisms involved in the intestinal absorption of dietary vitamin A and provitamin A carotenoids Biochim Biophys Acta, 1821 (2012), pp. 70-77 View PDFView articleView in ScopusGoogle Scholar 28 Farjo KM, Moiseyev G, Nikolaeva O, Sandell LL, Trainor PA, Ma JX RDH10 is the primary enzyme ...