Study Suggests High Dose Vitamin E ia an antagonist of Vitamin K

[JimChicago]

New study indicates Vitamin E at high doses (greater than 1,000 IU per day) may be an antagonist for Vitamin K

From:
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http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=169070
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Title: Effect of Vitamin E Supplementation on Vitamin K Status in Adults with Normal Coagulation Status

Authors
Booth, Sarah - TUFTS/HNRCA
Golly, Ines - UNIVERSITY OF MUNICH
Sacheck, Jennifer - TUFTS/HNRCA
Roubenoff, Ronenn - TUFTS/HNRCA
Dallal, Gerard - TUFTS/HNRCA
Hamada, Koichiro - TUFTS/HNRCA
Blumberg, Jeffrey - TUFTS/HNRCA


Submitted to: American Journal Of Clinical Nutrition
Publication Acceptance Date: December 19, 2003
Publication Date: July 1, 2004


Interpretive Summary: Cases of enhanced anticoagulant effect have been reported among patients taking oral anticoagulants in response to high dose vitamin E supplementation. Although a vitamin E-vitamin K interaction has been proposed to underlie this effect, it has not been systematically investigated in adults with normal coagulation. The objective of this study was to examine the effect of 12-week supplementation with high doses of vitamin E on measures of vitamin K status in men and women not taking oral anticoagulants. Vitamin K status was determined in 38 men and women with rheumatoid arthritis (Study A) and 32 healthy men (Study B) participating in two independent 12-week long studies employing vitamin E supplementation at doses of 1000 international units per day. One measure of vitamin K status, PIVKA-II, significantly increased in response to 12-week of vitamin E supplementation. An increase in PIVKA-II is indicative of poor vitamin K status. In contrast, other measures of vitamin K status did not change in response to the supplementation. In conclusion, high dose vitamin E supplementation reduced the function of the vitamin K-dependent proteins involved in normal coagulation. The clinical significance of these changes warrants further investigation, but it is possible that high doses of vitamin E antagonize vitamin K. Whether such an interaction is potentially beneficial or harmful remains to be determined.

Citation: Booth, S.L., Golly, I., Sacheck, J.M., Roubenoff, R., Dallal, G.E., Hamada, K., Blumberg, J.B. 2004. Effect Of Vitamin E Supplementation On Vitamin K Status In Adults With Normal Coagulation Status. American Journal Of Clinical Nutrition. 80:143-148.
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another article:

From:
http://www.emedicine.com/med/byname/vitamin-e-toxicity.htm
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Hematologic: Vitamin E can prolong the prothrombin time (PT) by inhibition of vitamin K?dependent carboxylase in animal models. Administration of vitamin K corrects this. High doses increase the vitamin K requirement and, therefore, cause coagulopathy only in patients who are deficient in vitamin K.
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[Guest]

In proving whether or not any medication has any effect, a prospective, randomized, double-blind, placebo-controlled study is the gold standard (why Vioxx was withdrawn). I have never seen the results of any of this proof-type study that showed any benefit to a human for high dose vitamin E. Therefore, I think that there is no reason that someone taking warfarin should be taking high-dose vitamin E (greater than 1000 units daily.)

 

[tobagotwo]

Agree on E

Agree on E

I second that, Al. The vitamin and supplement world is rife with unchecked marketing, product aggrandizement, and outright lies. However, I have read in several sources that amounts of vitamin E exceeding 400 IU/day not only do not achieve greater benefits, but may actually reduce its effectiveness. Generally, when you read about a supplement, they're encouraging you to take more, so when they suggest a limit, my ears usually perk up, as I suspect there's truth to it.

Vitamin E is generally referred to as one of the blood thinning supplements, along with Vitamin C, garlic and some others. The effect is not large from them, but you might want to see how they affect your personal INR if you up or change their dosages - check Al Lodwick's site for the scoop on that, as I'm way over my head when it comes to warfarin.

My wife's gynecologist had recommended higher doses of vitamin E (800 IU) for women who have une certaine age, but it was just based on one article she had read that it might help, not on any deep study. So wife is back to taking 400 IU.

If you want to maximize the value of the vitamin E you do take, ensure that the capsule you're taking has mixed tocopherols, not just d-alpha tocopherol.

If you don't mind going more expensive than that, there are E formulations that have both mixed tocopherals and tocotrienols. Tocotrienols are ballyhooed by supplement marketers to be beneficial in regard to arteriosclerosis. They may be helpful: it's up in the air as far as I'm concerned, but I haven't paid the extra dollars to try them.

I am wary of supplement claims, and I hope others are, too. Marketers of supplements seem to have very few scruples these days. That doesn't mean the supplements are bad, or that they do not help to a point. I believe many of them do. But common sense dictates that they can't be as effective as is frequently claimed, or we'd all be taking them and radiant with health. There are no "secret natural cures" that are being kept from the public by unscrupulous drug companies, bent on obtaining profits by thwarting the public good.

Best wishes,