2006 Mar;22(2):140-6.Author information1University of California-School of Medicine, Irvine, California, USA. hmsaid@uci.eduAbstractPURPOSE OF REVIEW: The molecular biology revolution has led to a significant improvement in our understanding of biological and physiological processes. Such expansion of knowledge has also covered the field of intestinal absorption of water-soluble vitamins and is the subject of this review.RECENT FINDINGS: Impressive progress has been made in the understanding of the mechanisms and regulation of transport of water-soluble vitamins at the cellular and molecular levels. In addition, the 5' regulatory regions of the genes that encode a number of the involved transporters have been cloned and characterized in vitro and in vivo in transgenic mice, thus providing important information about transcriptional regulation of these events. Furthermore, confocal imaging of live intestinal epithelial cells has led to significant progress in understanding the mechanisms involved in intracellular trafficking and membrane targeting of the carrier proteins and how clinical mutations lead to interference with transport.
Finally, the identification in the large intestine of efficient and specialized carrier-mediated systems that are capable of absorbing a number of the bacterially synthesized vitamins (thiamin, folate, biotin, riboflavin, pantothenic acid) has raised the possibility that this source of vitamins may play a role in regulating (fine tuning) the normal body homeostasis of these vitamins, and especially the vitamin level in the local colonocytes.SUMMARY: Water-soluble vitamin absorption involves regulated and specific mechanisms. Interference with the function of these mechanisms may lead to deficiency. The large intestine is capable of absorbing water-soluble vitamins that are synthesized by the normal microflora.PMID: 16462170 DOI: 10.1097/01.mog.0000203870.22706.52 [Indexed for MEDLINE] Publication typesResearch Support, N.I.H., ExtramuralResearch Support, U.S. Gov't, Non-P.H.S.ReviewMeSH termsAnimalsBiological TransportHumansIntestinal Absorption/physiology*SolubilityVitamins/pharmacokinetics*SubstanceVitaminsGrant supportDK 56061/DK/NIDDK NIH HHS/United StatesDK 58057/DK/NIDDK NIH HHS/United StatesFull Text SourcesLippincott Williams & WilkinsOvid Technologies, Inc.Other Literature SourcesCOS Scholar UniverseCited by Patents in - The Lens
How are water-soluble vitamins absorbed by the body? What is the role of water-soluble vitamins in the body?The IP address used for your Internet connection is part of a subnet that has been blocked from access to PubMed Central. Addresses across the entire subnet were used to download content in bulk, in violation of the terms of the PMC Copyright Notice. Use of PMC is free, but must comply with the terms of the Copyright Notice on the PMC site. For additional information, or to request that your IP address be unblocked, For requests to be unblocked, you must include all of the information in the box above in your message.We're sorry, the page you're looking for can't be found. It is possible that you used an outdated or expired MedicineNet link or you may have typed the address incorrectly. Please try searching using the search field above. If you're not sure of the spelling, type the first few letters, followed by an asterisk(*). To help you find what you are looking for, these links may help.
Browse our A-Z Lists: MedTerms Online Medical DictionaryBiochem J. 2011 Aug 1;437(3):357-72. Author information1School of Medicine, University of California-Irvine, Irvine, CA 92697, USA. hmsaid@uci.eduAbstractOur knowledge of the mechanisms and regulation of intestinal absorption of water-soluble vitamins under normal physiological conditions, and of the factors/conditions that affect and interfere with theses processes has been significantly expanded in recent years as a result of the availability of a host of valuable molecular/cellular tools. Although structurally and functionally unrelated, the water-soluble vitamins share the feature of being essential for normal cellular functions, growth and development, and that their deficiency leads to a variety of clinical abnormalities that range from anaemia to growth retardation and neurological disorders. Humans cannot synthesize water-soluble vitamins (with the exception of some endogenous synthesis of niacin) and must obtain these micronutrients from exogenous sources.
Thus body homoeostasis of these micronutrients depends on their normal absorption in the intestine. Interference with absorption, which occurs in a variety of conditions (e.g. congenital defects in the digestive or absorptive system, intestinal disease/resection, drug interaction and chronic alcohol use), leads to the development of deficiency (and sub-optimal status) and results in clinical abnormalities. It is well established now that intestinal absorption of the water-soluble vitamins ascorbate, biotin, folate, niacin, pantothenic acid, pyridoxine, riboflavin and thiamin is via specific carrier-mediated processes. These processes are regulated by a variety of factors and conditions, and the regulation involves transcriptional and/or post-transcriptional mechanisms. Also well recognized now is the fact that the large intestine possesses specific and efficient uptake systems to absorb a number of water-soluble vitamins that are synthesized by the normal microflora. This source may contribute to total body vitamin nutrition, and especially towards the cellular nutrition and health of the local colonocytes.