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Traber MG, Head B. Vitamin E: How much is enough, too much and why! Free Radic Biol Med 2021; 177:212-225. [PMID: 34699937 DOI: 10.1016/j.freeradbiomed.2021.10.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/08/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022]
Abstract
α-Tocopherol (α-T) is a required dietary nutrient for humans and thus is a vitamin. This narrative review focuses on vitamin E structures, functions, biological determinants and its deficiency symptoms in humans. The mechanisms for the preferential α-T tissue enrichment in the human body include the α-T transfer protein (TTPA) and the preferential metabolism of non-α-T forms. Potential new α-T biomarkers, pharmacokinetic data, and whether there are better approaches to evaluate and set the α-T dietary requirement are discussed. Finally, the possible role of α-T supplements in delay of chronic diseases and the evaluation of vitamin E safety are considered.
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Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, USA; School of Biological and Population Health Sciences, College of Public Health and Human Sciences, USA.
| | - Brian Head
- Linus Pauling Institute, USA; Molecular and Cell Biology Program, Oregon State University, Corvallis, OR, USA
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Shichiri M, Ishida N, Hagihara Y, Yoshida Y, Kume A, Suzuki H. Probucol induces the generation of lipid peroxidation products in erythrocytes and plasma of male cynomolgus macaques. J Clin Biochem Nutr 2018; 64:129-142. [PMID: 30936625 PMCID: PMC6436040 DOI: 10.3164/jcbn.18-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 08/18/2018] [Indexed: 12/27/2022] Open
Abstract
We previously reported that probucol, a lipid lowering agent, protected mice from malaria infection via depletion in plasma α-tocopherol. The antioxidant α-tocopherol in host circulation is necessary for the malaria parasites to protect themselves from oxidative stress in erythrocytes where high amounts of reactive oxygen species are generated. To assess the potential for the clinical application of probucol as an anti-malarial therapy, it was necessary to determine the effects of probucol by using primate experiments. Here we verified that probucol induces an α-tocopherol decrement in cynomolgus macaque erythrocytes and plasma. After 2 weeks of probucol administration at doses of 200 or 400 mg/kg/day, the α-tocopherol contents in erythrocytes tended to decrease. The contents of hydroxyoctadecadienoic acids and 7β-hydroxycholesterol, peroxidation products derived from linoleic acid and cholesterol, respectively, increased in erythrocytes. On the other hand, plasma α-tocopherol concentration showed a marginal decrement. Plasma lipid peroxidation products were transiently increased in the early stages of probucol administration. No adverse effects were observed throughout the experiment, although the dosage of probucol was higher than the clinical maximum dosage. Considering that malaria proliferates in erythrocytes, probucol-induced disruption of redox homeostasis in erythrocytes could be effective in the inhibition of parasite proliferation.
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Affiliation(s)
- Mototada Shichiri
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.,DBT-AIST International Laboratory for Advanced Biomedicine (DAILAB), 1-1-1 Higashi, Tsukuba-shi, Ibaraki 305-8562, Japan
| | - Noriko Ishida
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Yoshihisa Hagihara
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Yasukazu Yoshida
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
| | - Aiko Kume
- Research Unit for Functional Genomics, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro, Hokkaido 080-5555, Japan
| | - Hiroshi Suzuki
- Research Unit for Functional Genomics, National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro, Hokkaido 080-5555, Japan
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Reboul E. Vitamin E intestinal absorption: Regulation of membrane transport across the enterocyte. IUBMB Life 2018; 71:416-423. [PMID: 30308094 DOI: 10.1002/iub.1955] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 12/29/2022]
Abstract
Vitamin E is an essential molecule for our development and health. It has long been thought that it was absorbed and transported through cellular membranes by a passive diffusion process. However, data obtained during the past 15 years showed that its absorption is actually mediated, at least in part, by cholesterol membrane transporters including the scavenger receptor class B type I (SR-BI), CD36 molecule (CD36), NPC1-like transporter 1 (NPC1L1), and ATP-binding cassettes A1 and G1 (ABCA1 and ABCG1). This review focuses on the absorption process of vitamin E across the enterocyte. A special attention is given to the regulation of this process, including the possible competition with other fat-soluble micronutrients, and the modulation of transporter expressions. Overall, recent results noticeably increased the comprehension of vitamin E intestinal transport, but additional investigations are still required to fully appreciate the mechanisms governing vitamin E bioavailability. © 2018 IUBMB Life, 71(4):416-423, 2019.
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Rijpma A, Meulenbroek O, van Hees AMJ, Sijben JWC, Vellas B, Shah RC, Bennett DA, Scheltens P, Olde Rikkert MGM. Effects of Souvenaid on plasma micronutrient levels and fatty acid profiles in mild and mild-to-moderate Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2015. [PMID: 26213579 PMCID: PMC4513634 DOI: 10.1186/s13195-015-0134-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Circulating levels of uridine, selenium, vitamins B12, E and C, folate, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have been shown to be lower in patients with Alzheimer's disease (AD) than in healthy individuals. These low levels may affect disease pathways involved in synapse formation and neural functioning. Here, we investigated whether, and to what extent, circulating levels of micronutrients and fatty acids can be affected by oral supplementation with Souvenaid (containing a specific nutrient combination), using data derived from three randomized clinical trials (RCT) and an open-label extension (OLE) study with follow-up data from 12 to 48 weeks. METHODS Subjects with mild (RCT1, RCT2) or mild-to-moderate AD (RCT3) received active or control product once daily for 12-24 weeks or active product during the 24-week OLE following RCT2 (n = 212-527). Measurements included plasma levels of B vitamins, choline, vitamin E, selenium, uridine and homocysteine and proportions of DHA, EPA and total n-3 long-chain polyunsaturated fatty acids in plasma and erythrocytes. Between-group comparisons were made using t tests or non-parametric alternatives. RESULTS We found that 12-24-week active product intake increased plasma and/or erythrocyte micronutrients: uridine; choline; selenium; folate; vitamins B6, B12 and E; and fatty acid levels of DHA and EPA (all p < 0.001). In the OLE study, similar levels were reached in former control product/initial active product users, whereas 24-week continued active product intake showed no suggestion of a further increase in nutrient levels. CONCLUSIONS These data show that circulating levels of nutrients known to be decreased in the AD population can be increased in patients with mild and mild-tomoderate AD by 24-48-week oral supplementation with Souvenaid. In addition, to our knowledge, this is the first report of the effects of sustained dietary intake of uridine monophosphate on plasma uridine levels in humans. Uptake of nutrients is observed within 6 weeks, and a plateau phase is reached for most nutrients during prolonged intake, thus increasing the availability of precursors and cofactors in the circulation that may be used for the formation and function of neuronal membranes and synapses in the brain.
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Affiliation(s)
- Anne Rijpma
- Radboud Alzheimer Center, Department of Geriatric Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Olga Meulenbroek
- Radboud Alzheimer Center, Department of Geriatric Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Anneke M J van Hees
- Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, The Netherlands
| | - John W C Sijben
- Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, The Netherlands
| | | | - Raj C Shah
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL USA
| | - Philip Scheltens
- Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands
| | - Marcel G M Olde Rikkert
- Radboud Alzheimer Center, Department of Geriatric Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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Tegenge MA, Mitkus RJ. A first-generation physiologically based pharmacokinetic (PBPK) model of alpha-tocopherol in human influenza vaccine adjuvant. Regul Toxicol Pharmacol 2015; 71:353-64. [DOI: 10.1016/j.yrtph.2015.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 02/02/2015] [Accepted: 02/04/2015] [Indexed: 12/30/2022]
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Traber MG, Leonard SW, Bobe G, Fu X, Saltzman E, Grusak MA, Booth SL. α-Tocopherol disappearance rates from plasma depend on lipid concentrations: studies using deuterium-labeled collard greens in younger and older adults. Am J Clin Nutr 2015; 101:752-9. [PMID: 25739929 PMCID: PMC4381779 DOI: 10.3945/ajcn.114.100966] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/23/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Little is known about α-tocopherol's bioavailability as a constituent of food or its dependence on a subject's age. OBJECTIVE To evaluate the α-tocopherol bioavailability from food, we used collard greens grown in deuterated water ((2)H collard greens) as a source of deuterium-labeled ((2)H) α-tocopherol consumed by younger and older adults in a post hoc analysis of a vitamin K study. DESIGN Younger (mean ± SD age: 32 ± 7 y; n = 12 women and 9 men) and older (aged 67 ± 8 y; n = 8 women and 12 men) adults consumed a test breakfast that included 120 g (2)H collard greens (1.2 ± 0.1 mg (2)H-α-tocopherol). Plasma unlabeled α-tocopherol and (2)H-α-tocopherol were measured by using liquid chromatography-mass spectrometry from fasting (>12 h) blood samples drawn before breakfast (0 h) and at 24, 48, and 72 h and from postprandial samples collected at 4, 5, 6, 7, 9, 12, and 16 h. RESULTS Times (12.6 ± 2.5 h) of maximum plasma (2)H-α-tocopherol concentrations (0.82% ± 0.59% total α-tocopherol), fractional disappearance rates (0.63 ± 0.26 pools/d), half-lives (30 ± 11 h), and the minimum estimated (2)H-α-tocopherol absorbed (24% ± 16%) did not vary between age groups or sexes (n = 41). Unlabeled α-tocopherol concentrations were higher in older adults (26.4 ± 8.6 μmol/L) than in younger adults (19.3 ± 4.2 μmol/L; P = 0.0019) and correlated with serum lipids (r = 0.4938, P = 0.0012). In addition, (2)H-α-tocopherol half-lives were correlated with lipids (r = 0.4361, P = 0.0044). CONCLUSIONS Paradoxically, α-tocopherol remained in circulation longer in participants with higher serum lipids, but the (2)H-α-tocopherol absorbed was not dependent on the plasma lipid status. Neither variable was dependent on age. These data suggest that plasma α-tocopherol concentrations are more dependent on mechanisms that control circulating lipids rather than those related to its absorption and initial incorporation into plasma. This trial was registered at clinicaltrials.gov as NCT0036232.
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Affiliation(s)
- Maret G Traber
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Scott W Leonard
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Gerd Bobe
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Xueyan Fu
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Edward Saltzman
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Michael A Grusak
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
| | - Sarah L Booth
- From the Linus Pauling Institute, Oregon State University, Corvallis, OR (MGT, SWL, and GB); the USDA Human Nutrition Center on Aging, Tufts University, Boston, MA (XF, ES, and SLB); and the USDA/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX (MAG)
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Borel P, Desmarchelier C, Nowicki M, Bott R, Tourniaire F. Can genetic variability in α-tocopherol bioavailability explain the heterogeneous response to α-tocopherol supplements? Antioxid Redox Signal 2015; 22:669-78. [PMID: 25289663 DOI: 10.1089/ars.2014.6144] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Both vitamin E (VE) consumption and blood VE status have been negatively associated with the incidence of degenerative diseases and some cancers. However, the response to VE supplementation is very variable among individuals. This could be due to interindividual variability in VE bioavailability, due, at least partly, to genetic variations in genes involved in VE metabolism. Thus, the main objective was to identify single nucleotide polymorphisms (SNPs) that may be involved in the interindividual variability in α-tocopherol (TOL) bioavailability. The postprandial chylomicron (CM) TOL response (area under the curve of the postprandial CM TOL concentration) to a TOL-rich meal was highly variable (coefficient of variation=81%; n=38). This response was positively correlated with the fasting plasma TOL concentration (r=0.5, p=0.004). A significant (p=1.8×10(-8)) partial least-squares regression model, which included 28 SNPs in 11 genes, explained 82% of this response. First evidence that the interindividual variability in TOL bioavailability is, at least partly, modulated by a combination of SNPs. TOL bioavailability is, at least partly, modulated by genetic variations that can affect long-term TOL status. This allows us to propose a new hypothesis that links the biological response to VE supplementation with one's individual genetic characteristics.
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Roager HM, Sulek K, Skov K, Frandsen HL, Smedsgaard J, Wilcks A, Skov TH, Villas-Boas SG, Licht TR. Lactobacillus acidophilus NCFM affects vitamin E acetate metabolism and intestinal bile acid signature in monocolonized mice. Gut Microbes 2014; 5:296-303. [PMID: 24717228 PMCID: PMC4153766 DOI: 10.4161/gmic.28806] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Monocolonization of germ-free (GF) mice enables the study of specific bacterial species in vivo. Lactobacillus acidophilus NCFM(TM) (NCFM) is a probiotic strain; however, many of the mechanisms behind its health-promoting effect remain unknown. Here, we studied the effects of NCFM on the metabolome of jejunum, cecum, and colon of NCFM monocolonized (MC) and GF mice using liquid chromatography coupled to mass-spectrometry (LC-MS). The study adds to existing evidence that NCFM in vivo affects the bile acid signature of mice, in particular by deconjugation. Furthermore, we confirmed that carbohydrate metabolism is affected by NCFM in the mouse intestine as especially the digestion of oligosaccharides (penta- and tetrasaccharides) was increased in MC mice. Additionally, levels of α-tocopherol acetate (vitamin E acetate) were higher in the intestine of GF mice than in MC mice, suggesting that NCFM affects the vitamin E acetate metabolism. NCFM did not digest vitamin E acetate in vitro, suggesting that direct bacterial metabolism was not the cause of the altered metabolome in vivo. Taken together, our results suggest that NCFM affects intestinal carbohydrate metabolism, bile acid metabolism and vitamin E metabolism, although it remains to be investigated whether this effect is unique to NCFM.
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Affiliation(s)
- Henrik M Roager
- National Food Institute; Technical University of Denmark; Søborg, Denmark
| | - Karolina Sulek
- Liggins Institute; University of Auckland; Auckland, New Zealand,School of Biological Sciences; University of Auckland; Auckland, New Zealand
| | - Kasper Skov
- National Food Institute; Technical University of Denmark; Søborg, Denmark
| | - Henrik L Frandsen
- National Food Institute; Technical University of Denmark; Søborg, Denmark
| | - Jørn Smedsgaard
- National Food Institute; Technical University of Denmark; Søborg, Denmark
| | - Andrea Wilcks
- Faculty of Health and Medical Sciences; University of Copenhagen; København, Denmark
| | - Thomas H Skov
- Department of Food Science; Faculty of Science; University of Copenhagen; København, Denmark
| | - Silas G Villas-Boas
- School of Biological Sciences; University of Auckland; Auckland, New Zealand
| | - Tine R Licht
- National Food Institute; Technical University of Denmark; Søborg, Denmark,Correspondence to: Tine R Licht,
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Reboul E. Absorption of vitamin A and carotenoids by the enterocyte: focus on transport proteins. Nutrients 2013; 5:3563-81. [PMID: 24036530 PMCID: PMC3798921 DOI: 10.3390/nu5093563] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/19/2013] [Accepted: 08/26/2013] [Indexed: 12/15/2022] Open
Abstract
Vitamin A deficiency is a public health problem in most developing countries, especially in children and pregnant women. It is thus a priority in health policy to improve preformed vitamin A and/or provitamin A carotenoid status in these individuals. A more accurate understanding of the molecular mechanisms of intestinal vitamin A absorption is a key step in this direction. It was long thought that β-carotene (the main provitamin A carotenoid in human diet), and thus all carotenoids, were absorbed by a passive diffusion process, and that preformed vitamin A (retinol) absorption occurred via an unidentified energy-dependent transporter. The discovery of proteins able to facilitate carotenoid uptake and secretion by the enterocyte during the past decade has challenged established assumptions, and the elucidation of the mechanisms of retinol intestinal absorption is in progress. After an overview of vitamin A and carotenoid fate during gastro-duodenal digestion, our focus will be directed to the putative or identified proteins participating in the intestinal membrane and cellular transport of vitamin A and carotenoids across the enterocyte (i.e., Scavenger Receptors or Cellular Retinol Binding Proteins, among others). Further progress in the identification of the proteins involved in intestinal transport of vitamin A and carotenoids across the enterocyte is of major importance for optimizing their bioavailability.
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Affiliation(s)
- Emmanuelle Reboul
- INRA, UMR1260, Nutrition, Obesity and Risk of Thrombosis, Marseille F-13385, France.
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Borel P, Preveraud D, Desmarchelier C. Bioavailability of vitamin E in humans: an update. Nutr Rev 2013; 71:319-31. [PMID: 23731443 DOI: 10.1111/nure.12026] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Vitamin E is essential for human health and may play a role in the prevention of some degenerative diseases. Its bioavailability, however, is wide ranging and is affected by numerous factors. Recent findings showing that the intestinal absorption of vitamin E involves proteins have raised new relevant questions about factors that can affect bioavailability. It is, therefore, opportune to present a current overview of this topic. This review begins by exploring what is known, as well as what is unknown, about the metabolization of vitamin E in the human upper gastrointestinal tract and then presents a methodical evaluation of factors assumed to affect vitamin E bioavailability. Three main conclusions can be drawn. First, the proteins ABCA1, NPC1L1, and SR-BI are implicated in the absorption of vitamin E. Second, the efficiency of vitamin E absorption is widely variable, though not accurately known (i.e., between 10% and 79%), and is affected by several dietary factors (e.g., food matrix, fat, and fat-soluble micronutrients). Finally, numerous unanswered questions remain about the metabolization of vitamin E in the intestinal lumen and about the factors affecting the efficiency of vitamin E absorption.
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Affiliation(s)
- Patrick Borel
- Institut National de la Santé et de la Recherche Médicale INSERM, Unité Mixte de Recherche UMR 1062, Nutrition, Obesity and Risk of Thrombosis, Marseilles, France.
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Novotny JA, Fadel JG, Holstege DM, Furr HC, Clifford AJ. This kinetic, bioavailability, and metabolism study of RRR-α-tocopherol in healthy adults suggests lower intake requirements than previous estimates. J Nutr 2012; 142:2105-11. [PMID: 23077194 PMCID: PMC3497961 DOI: 10.3945/jn.112.166462] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Kinetic models enable nutrient needs and kinetic behaviors to be quantified and provide mechanistic insights into metabolism. Therefore, we modeled and quantified the kinetics, bioavailability, and metabolism of RRR-α-tocopherol in 12 healthy adults. Six men and 6 women, aged 27 ± 6 y, each ingested 1.81 nmol of [5(-14)CH(3)]-(2R, 4'R, 8'R)-α-tocopherol; each dose had 3.70 kBq of (14)C. Complete collections of urine and feces were made over the first 21 d from dosing. Serial blood samples were drawn over the first 70 d from dosing. All specimens were analyzed for RRR-α-tocopherol. Specimens were also analyzed for (14)C using accelerator MS. From these data, we modeled and quantified the kinetics of RRR-α-tocopherol in vivo in humans. The model had 11 compartments, 3 delay compartments, and reservoirs for urine and feces. Bioavailability of RRR-α-tocopherol was 81 ± 1%. The model estimated residence time and half-life of the slowest turning-over compartment of α-tocopherol (adipose tissue) at 499 ± 702 d and 184 ± 48 d, respectively. The total body store of RRR-α-tocopherol was 25,900 ± 6=220 μmol (11 ± 3 g) and we calculated the adipose tissue level to be 1.53 μmol/g (657 μg/g). We found that a daily intake of 9.2 μmol (4 mg) of RRR-α-tocopherol maintained plasma RRR-α-tocopherol concentrations at 23 μmol/L. These findings suggest that the dietary requirement for vitamin E may be less than that currently recommended and these results will be important for future updates of intake recommendations.
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Affiliation(s)
| | | | | | - Harold C. Furr
- Department of Nutrition, University of Wisconsin, Madison, WI
| | - Andrew J. Clifford
- Department of Nutrition, University of California, Davis, CA; and,To whom correspondence should be addressed. E-mail:
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Proteins involved in uptake, intracellular transport and basolateral secretion of fat-soluble vitamins and carotenoids by mammalian enterocytes. Prog Lipid Res 2011; 50:388-402. [DOI: 10.1016/j.plipres.2011.07.001] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/24/2011] [Accepted: 06/30/2011] [Indexed: 12/31/2022]
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13
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Traber MG, Stevens JF. Vitamins C and E: beneficial effects from a mechanistic perspective. Free Radic Biol Med 2011; 51:1000-13. [PMID: 21664268 PMCID: PMC3156342 DOI: 10.1016/j.freeradbiomed.2011.05.017] [Citation(s) in RCA: 531] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/13/2011] [Accepted: 05/17/2011] [Indexed: 02/07/2023]
Abstract
The mechanistic properties of two dietary antioxidants that are required by humans, vitamins C and E, are discussed relative to their biological effects. Vitamin C (ascorbic acid) is an essential cofactor for α-ketoglutarate-dependent dioxygenases. Examples are prolyl hydroxylases, which play a role in the biosynthesis of collagen and in down-regulation of hypoxia-inducible factor (HIF)-1, a transcription factor that regulates many genes responsible for tumor growth, energy metabolism, and neutrophil function and apoptosis. Vitamin C-dependent inhibition of the HIF pathway may provide alternative or additional approaches for controlling tumor progression, infections, and inflammation. Vitamin E (α-tocopherol) functions as an essential lipid-soluble antioxidant, scavenging hydroperoxyl radicals in a lipid milieu. Human symptoms of vitamin E deficiency suggest that its antioxidant properties play a major role in protecting erythrocyte membranes and nervous tissues. As an antioxidant, vitamin C provides protection against oxidative stress-induced cellular damage by scavenging of reactive oxygen species, by vitamin E-dependent neutralization of lipid hydroperoxyl radicals, and by protecting proteins from alkylation by electrophilic lipid peroxidation products. These bioactivities bear relevance to inflammatory disorders. Vitamin C also plays a role in the function of endothelial nitric oxide synthase (eNOS) by recycling the eNOS cofactor, tetrahydrobiopterin, which is relevant to arterial elasticity and blood pressure regulation. Evidence from plants supports a role for vitamin C in the formation of covalent adducts with electrophilic secondary metabolites. Mechanism-based effects of vitamin C and E supplementation on biomarkers and on clinical outcomes from randomized, placebo-controlled trials are emphasized in this review.
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Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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Chuang JC, Matel HD, Nambiar KP, Kim SH, Fadel JG, Holstege DM, Clifford AJ. Quantitation of [5-14CH3]-(2R, 4'R, 8'R)-α-tocopherol in humans. J Nutr 2011; 141:1482-8. [PMID: 21715470 PMCID: PMC3138640 DOI: 10.3945/jn.111.138925] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Half-lives of α-tocopherol in plasma have been reported as 2-3 d, whereas the Elgin Study required >2 y to deplete α-tocopherol, so gaps exist in our quantitative understanding of human α-tocopherol metabolism. Therefore, 6 men and 6 women aged 27 ± 6 y (mean ± SD) ingested 1.81 nmol, 3.70 kBq of [5-(14)CH(3)]-(2R, 4'R, 8'R)-α-tocopherol. The levels of (14)C in blood plasma and washed RBC were monitored frequently from 0 to 460 d while the levels of (14)C in urine and feces were monitored from 0 to 21 d. Total fecal elimination (fecal + metabolic fecal) was 23.24 ± 5.81% of the (14)C dose, so feces over urine was the major route of elimination of the ingested [5-(14)CH(3)]-(2R, 4'R, 8'R)-α-tocopherol, consistent with prior estimates. The half-life of α-tocopherol varied in plasma and RBC according to the duration of study. The minute dose coupled with frequent monitoring over 460 d and 21 d for blood, urine, and feces ensured the [5-(14)CH(3)]-(2R, 4'R, 8'R)-α-tocopherol (the tracer) had the chance to fully mix with the endogenous [5-(14)CH(3)]-(2R, 4'R, 8'R)-α-tocopherol (the tracee). The (14)C levels in neither plasma nor RBC had returned to baseline by d 460, indicating that the t(1/2) of [5-CH(3)]-(2R, 4'R, 8'R)-α-tocopherol in human blood was longer than prior estimates.
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Affiliation(s)
| | - Hosea D. Matel
- Department of Chemistry, University of California, Davis, CA 95616
| | | | - Seung-Hyun Kim
- Department of Nutrition, University of California, Davis, CA 95616
| | - James G. Fadel
- Department of Animal Science, University of California, Davis, CA 95616
| | - Dirk M. Holstege
- UC Davis Analytical Laboratory, University of California, Davis, CA 95616
| | - Andrew J. Clifford
- Department of Nutrition, University of California, Davis, CA 95616,To whom correspondence should be addressed. E-mail:
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Fiebrich HB, Van Den Berg G, Kema IP, Links TP, Kleibeuker JH, Van Beek AP, Walenkamp AME, Sluiter WJ, De Vries EGE. Deficiencies in fat-soluble vitamins in long-term users of somatostatin analogue. Aliment Pharmacol Ther 2010; 32:1398-404. [PMID: 21050243 DOI: 10.1111/j.1365-2036.2010.04479.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Somatostatin analogues are administered to control hormone hypersecretion in acromegaly and carcinoid patients. Somatostatin analogues can increase fat in the stools, which can lead to loss of fat-soluble vitamins. The effect of long-term somatostatin analogue use on vitamin levels remains unknown. AIM To investigate the prevalence of fat-soluble vitamin deficiencies in long-term somatostatin analogue users. METHODS All acromegaly and carcinoid patients using somatostatin analogues for ≥ 18 months visiting the University Medical Center Groningen between December 2008 and April 2009 were eligible. Vitamin levels of fat-soluble vitamins in blood, clinical and vitamin-dependent laboratory parameters were collected. RESULTS In all, 19 acromegaly and 35 carcinoid patients were included. Twelve patients experienced steatorrhoea; two carcinoid patients experienced night blindness. Forty-two (78%) were deficient for one or more vitamins, and 32% (n = 17) had multiple deficiencies. Deficiencies for vitamin A, D, E, K1 and E in erythrocytes occurred in 6%, 28%, 15%, 63% and 58% of the patients. Prevalence of vitamin D, E and K1 deficiencies was similar in both patient groups. Treatment duration did not influence vitamin levels. The length of intestinal resection and age correlated negatively with vitamin A levels. CONCLUSIONS Fat-soluble vitamin deficiencies are frequent during long-term somatostatin analogue treatment. Therefore, fat-soluble vitamins should be monitored in these patients.
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Affiliation(s)
- H-B Fiebrich
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
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Symposium 2: Modern approaches to nutritional research challenges: Targeted and non-targeted approaches for metabolite profiling in nutritional research. Proc Nutr Soc 2009; 69:95-102. [PMID: 19954566 DOI: 10.1017/s0029665109991704] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present report discusses targeted and non-targeted approaches to monitor single nutrients and global metabolite profiles in nutritional research. Non-targeted approaches such as metabolomics allow for the global description of metabolites in a biological sample and combine an analytical platform with multivariate data analysis to visualise patterns between sample groups. In nutritional research metabolomics has generated much interest as it has the potential to identify changes to metabolic pathways induced by diet or single nutrients, to explore relationships between diet and disease and to discover biomarkers of diet and disease. Although still in its infancy, a number of studies applying this technology have been performed; for example, the first study in 2003 investigated isoflavone metabolism in females, while the most recent study has demonstrated changes to various metabolic pathways during a glucose tolerance test. As a relatively new technology metabolomics is faced with a number of limitations and challenges including the standardisation of study design and methodology and the need for careful consideration of data analysis, interpretation and identification. Targeted approaches are used to monitor single or multiple nutrient and/or metabolite status to obtain information on concentration, absorption, distribution, metabolism and elimination. Such applications are currently widespread in nutritional research and one example, using stable isotopes to monitor nutrient status, is discussed in more detail. These applications represent innovative approaches in nutritional research to investigate the role of both single nutrients and diet in health and disease.
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Abstract
PURPOSE OF REVIEW Recent developments in mass spectrometric methodology, in particular the widespread adoption of liquid chromatography/mass spectrometry, have presented investigators with new opportunities to investigate micronutrient absorption and metabolism. This review focuses on recent reports of the use of stable isotope techniques to facilitate research into vitamin uptake and utilization in humans. RECENT FINDINGS Stable isotopes are used principally in two ways, as analytical standards in isotope dilution assays and as tracers in studies of physiology. There have been a number of advances in both fields recently for almost all of the vitamins. In particular, the effects of food preparation and meal composition on vitamin bioavailability are being probed more widely than before. SUMMARY A considerable amount of method development has been reported. We now have the opportunity to consolidate our understanding of vitamin metabolism to better inform the dietary recommendations for optimal health.
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Affiliation(s)
- Leslie J C Bluck
- MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK.
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Abstract
Vitamin E is an important nutrient with antioxidant and non-antioxidant functions, and certain evidence suggests that it has a cardiovascular protective role. It is therefore important to maintain an optimal vitamin E status. In the present paper, a number of MS applications to monitor vitamin E status and its interactions, including the use of stable-isotope-labelled vitamin E and metabonomics, are highlighted. Specifically, stable-isotope studies have been used to monitor vitamin E absorption, hepatic processing and lipoprotein transport. As oxidative stress may influence vitamin E status, a number of studies comparing vitamin E biokinetics and metabolism in cigarette smokers and non-smokers have been able to show differences in vitamin E processing in smokers. Metabonomics represents a method to identify changes to metabolite profiles, offering the potential to investigate interactions between vitamin E and metabolic pathways. These applications represent innovative approaches to investigate the role of vitamin E in health and disease.
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Oommen S, Vasu VT, Leonard SW, Traber MG, Cross CE, Gohil K. Genome wide responses of murine lungs to dietary alpha-tocopherol. Free Radic Res 2007; 41:98-109. [PMID: 17164183 PMCID: PMC2782686 DOI: 10.1080/10715760600935567] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Alpha-tocopherol (alpha-T) may affect biological processes by modulating mRNA concentrations. This study screened the responses of approximately 15,000 lung mRNAs to dietary alpha-T in mice. The lung was chosen as the target organ because it is subjected to cyclical variations in oxidant and inflammatory stressors and alpha-T has been implicated in their modulations. The analysis identified approximately 400 mRNAs sensitive to alpha-T status of lungs determined by dietary alpha-T. The female lung transcriptome appears to be more sensitive to the alpha-T status than that of the male lungs. Here, we focus on the induction of 13 cytoskeleton genes by dietary alpha-T because they were similarly induced in the male and the female lungs. Their inductions were confirmed by quantitative-real-time-polymerase chain reaction (qRT-PCR). Immunohistochemical analyses of three of the encoded proteins suggest that they are expressed in lung vasculature and alveolar regions. The data suggest that the lung alpha-T status may modulate cytoarchitecture of lungs.
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Affiliation(s)
- Saji Oommen
- Division of Pulmonary and Critical Care, Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California, Davis, CA 95616, USA
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Clifford AJ, de Moura FF, Ho CC, Chuang JC, Follett J, Fadel JG, Novotny JA. A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Am J Clin Nutr 2006; 84:1430-41. [PMID: 17158427 DOI: 10.1093/ajcn/84.6.1430] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Quantitation of human vitamin E metabolism is incomplete, so we quantified RRR- and all-rac-alpha-tocopherol metabolism in an adult. OBJECTIVE The objective of the study was to quantify and interpret in vivo human vitamin E metabolism. DESIGN A man was given an oral dose of 0.001821 micromol [5-14CH3]RRR-alpha-tocopheryl acetate (with 101.5 nCi 14C), and its fate in plasma, plasma lipoproteins, urine, and feces was measured over time. Data were analyzed and interpreted by using kinetic modeling. The protocol was repeated later with 0.001667 micromol [5-14CH3]all-rac-alpha-tocopheryl acetate (with 99.98 nCi 14C). RESULTS RRR-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate were absorbed equally well (fractional absorption: approximately 0.775). The main route of elimination was urine, and approximately 90% of the absorbed dose was alpha-2(2'-carboxyethyl)-6-hydroxychroman. Whereas 93.8% of RRR-alpha-tocopherol flow to liver kinetic pool B from plasma was returned to plasma, only 80% of the flow of all-rac-alpha-tocopherol returned to plasma; the difference (14%) was degraded and eliminated. Thus, for newly digested alpha-tocopherol, the all-rac form is preferentially degraded and eliminated over the RRR form. Respective residence times in liver kinetic pool A and plasma for RRR-alpha-tocopherol were 1.16 and 2.19 times as long as those for all-rac-alpha-tocopherol. Model-estimated distributions of plasma alpha-tocopherol, extrahepatic tissue alpha-tocopherol, and liver kinetic pool B for RRR-alpha-tocopherol were, respectively, 6.77, 2.71, and 3.91 times as great as those for all-rac-alpha-tocopherol. Of the lipoproteins, HDL had the lowest 14C enrichment. Liver had 2 kinetically distinct alpha-tocopherol pools. CONCLUSIONS Both isomers were well absorbed; all-rac-alpha-tocopherol was preferentially degraded and eliminated in urine, the major route. RRR-alpha-tocopherol had a longer residence time and larger distribution than did all-rac-alpha-tocopherol. Liver had 2 distinct alpha-tocopherol pools. The model is a hypothesis, its estimates are model-dependent, and it encourages further testing.
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Affiliation(s)
- Andrew J Clifford
- Department of Nutrition, University of California, Davis, Davis, CA 5616-8669, USA.
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