Effect of vitamin E supplementation on vitamin K status in adults with normal coagulation status
| Autor: | Gerard E. Dallal, Koichiro Hamada, Ines Golly, Ronenn Roubenoff, Jennifer M. Sacheck, Sarah L. Booth, Jeffrey B. Blumberg |
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| Rok vydání: | 2004 |
| Předmět: |
Vitamin
Adult Male medicine.medical_specialty Vitamin K medicine.medical_treatment alpha-Tocopherol Medicine (miscellaneous) Arthritis Nutritional Status Antioxidants law.invention Arthritis Rheumatoid chemistry.chemical_compound Randomized controlled trial law Internal medicine medicine Humans Vitamin E Clinical significance Blood Coagulation Aged Aged 80 and over Nutrition and Dietetics business.industry Middle Aged medicine.disease Clinical trial Endocrinology chemistry Rheumatoid arthritis Dietary Supplements Female business |
| Zdroj: | The American journal of clinical nutrition. 80(1) |
| ISSN: | 0002-9165 |
| Popis: | BACKGROUND Cases of enhanced anticoagulant effect in response to high-dose vitamin E supplementation have been reported among patients taking oral anticoagulants. Although a vitamin E-vitamin K interaction was proposed to underlie this effect, it has not been systematically investigated in adults with normal baseline coagulation status. OBJECTIVE The objective was to study the effect of 12 wk of supplementation with 1000 IU RRR-alpha-tocopherol/d on biochemical measures of vitamin K status in men and women not taking oral anticoagulants. DESIGN Vitamin K status, which was assessed with the use of plasma phylloquinone concentrations, the degree of under-gamma-carboxylation of prothrombin (proteins induced by vitamin K absence-factor II, PIVKA-II), and the percentage of undercarboxylated osteocalcin (ucOC), was determined in 38 men and women with rheumatoid arthritis (study A) and in 32 healthy men (study B) participating in 2 independent, 12-wk randomized clinical trials of vitamin E supplementation (1000 IU/d). RESULTS Mean (+/- SD) PIVKA-II increased from 1.7 +/- 1.7 to 11.9 +/- 16.1 ng/mL (P < 0.001) in study A and from 1.8 +/- 0.6 to 5.3 +/- 3.9 ng/mL (P < 0.001) in study B in response to 12 wk of vitamin E supplementation. An increase in PIVKA-II is indicative of poor vitamin K status. In contrast, the other measures of vitamin K status (ie, plasma phylloquinone concentration and percentage of ucOC) did not change significantly in response to the supplementation. CONCLUSIONS High-dose vitamin E supplementation increased PIVKA-II in adults not receiving oral anticoagulant therapy. The clinical significance of these changes warrants further investigation, but high doses of vitamin E may antagonize vitamin K. Whether such an interaction is potentially beneficial or harmful remains to be determined. |
| Databáze: | OpenAIRE |
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