Vitamin E toxicity Domina Petric MD Vitamin E

Vitamin E toxicity Domina Petric, MD

Vitamin E toxicity Vitamin E is one of the least toxic of the vitamins. Daily doses as high as 400 IU can be considered harmless. Large oral doses as great as 3200 IU have not been found to have consistent ill effects. January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 2

Vitamin E toxicity • At very high doses, however, vitamin E can antagonize the functions of other fat-soluble vitamins. • This can be antagonised with increased dietary supplements of the appropriate vitamins: vitamins D, A and K. • Isolated reports of negative effects in patients consuming up to 1000 IU of vitamin E per day included headache, fatigue, nausea, double vision, muscular weakness, mild creatinuria and gastrointestinal distress. January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 3

Fat soluble vitamins Vitamin K Vitamin E Fat soluble vitamins Vitamin A Vitamin D January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 4

Vitamin E toxicity The least toxic of vitamins HEADACHE FATIGUE NAUSEA Individual cases Vitamin E intoxication Dose >1000 IU/day January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. DOUBLE VISION MUSCULAR WEAKNESS CREATINURIA GASTROINTESTINAL DISTRESS 5

Vitamin E toxicity • Potentially deleterious metabolic effects of high level vitamin E status include inhibitions of retinyl ester hydrolase and vitamin Kdependent carboxylations. • Patients of normal coagulation status given high doses of vitamin E (at least 1000 IU/day) showed decreased γ-carboxylation and decreased functionality of prothrombin. January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 6

Vitamin E toxicity Tocopherylquinone has structural similarities to vitamin K and may act as an inhibitor of vitamin K metabolism. January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 7

Conclusion Vitamin E is safe over a wide range of intakes that would extend to approximately 1600 IU/day for most healthy adults. January 5, 2022 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 8

Literature • Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. January 5, 2022 9