ARS | Publication request: Extrahepatic Tissue Concentrations of Vitamin K are Lower in Rats Fed a High Vitamin E Diet

Submitted to: Nutrition and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2006
Publication Date: July 1, 2006
Publisher's URL: http://www.nutritionandmetabolism.com/content/3/1/29
Citation: Trovar, A., Ameho, C.K., Blumberg, J., Peterson, J.W., Smith, D., Booth, S.L. 2006. Extrahepatic Tissue Concentrations of Vitamin K are Lower in Rats Fed a High Vitamin E Diet. Nutrition and Metabolism. 3:29.

Interpretive Summary: High levels of vitamin E supplementation have been reported to cause bleeding due to vitamin K deficiency, primarily in patients on oral anticoagulants. The effect of different levels of vitamin E on vitamin K concentrations, while maintaining a constant intake of phylloquinone, was examined in rats. Thirty-three (33) male rats were fed one of 3 diets for 12 weeks: 13 rats were fed the control diet that met the dietary requirements of vitamin E; 10 rats were fed a vitamin E- supplemented diet; and 10 rats were fed a vitamin E deficient diet. All 3 diets contained the same amount of vitamin K. At the end of the study, vitamin K concentrations were consistently lower in the kidney, spleen and brain in the vitamin E-supplemented group compared to the vitamin E-deficient group. However no differences in the vitamin K concentrations were found in plasma, liver or testis when the different amounts of vitamin E intake were compared. There appears to be certain tissues in which vitamin E supplementation can reduce concentrations of vitamin K.

Technical Abstract: An adverse hematological interaction between vitamins E and K has been reported, primarily in patients on anticoagulants. The effect of different levels of dietary a-tocopherol on phylloquinone and menaquinone-4 (MK-4) concentrations, while maintaining a constant intake of phylloquinone, was examined in rat tissues. Male 4-wk old Fischer 344 rats (n=33) were fed one of 3 diets for 12 wk: control (n=13) with 30 mg a-tocopherol acetate/kg diet; vitamin E supplemented (E+, n=10) with 100 mg a-tocopherol acetate/kg diet; and vitamin E deficient (E-, n=10) with <10 mg total tocopherols/kg diet. All 3 diets contained 470 +/-80 ug phylloquinone/ kg diet. Phylloquinone concentrations were consistently lower (P < 0.05) in the E+ compared to the E- group (spleen: 531 vs. 735; kidney: 20 vs. 94, brain: 136 vs. 53 pmol/g protein respectively); no statistically significant differences between groups were found in plasma, liver or testis. Similar results were noted with MK-4 concentrations in response to '-tocopherol supplementation. There appears to be a tissue-specific interaction between vitamins E and K when vitamin E is supplemented in rat diets.