Vitamins

Vitamin E

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Vitamin E, Alpha Tocopherol

  • Background
  1. Vitamin E is a complex of 8 different fat soluble molecules (4 tocopherols and 4 tocotrienols)
    1. Of the 8 compounds in Vitamin E, only Alpha Tocopherol is functional in humans
    2. Antioxidant properties include donating electrons to lipids in their free radical form, reducing their oxidative effects
  • Mechanism
  1. Vegetable and Seed Oils: gamma-tocopherol
    1. Antioxidant
    2. Usual daily intake 15 IU/day
  2. Supplements: alpha-tocopherol
    1. May block antioxidant effect of natural foods
    2. May have pro-Oxidant effect
      1. S Christen (1997) Proc Natl Acad Sci 64:3217 [PubMed]
  • Preparations
  • Sources
  1. Wheat germ
  2. Fish liver oil
  3. Nuts
  4. Vegetable Oil
    1. Corn oil
    2. Cottonseed oil
    3. Sunflower oil
    4. Soybean oil
  5. Green vegetables
    1. Beet greens
    2. Collard greens
    3. Spinach
    4. Asparagus
  • Efficacy
  • Potential Benefits
  1. May delay progression of Alzheimer's Disease
    1. May slow functional decline in mild to moderate Dementia (in those on Cholinesterase Inhibitor)
      1. Dysken (2014) JAMA 311(1):33-44 [PubMed]
    2. Initial studies showed slower functional decline
      1. Sano (1997) N Engl J Med 336:1216-22 [PubMed]
    3. Insufficient evidence to recommend by Cochrane
      1. Tabet (2003) Cochrane Database Syst Rev, CD002854 [PubMed]
  2. May boost immune response in elderly
    1. Study (DBPCT) of those over age 65 years (n=88)
      1. Measured Antigen produced induration to PPD
      2. Marked increase induration with 200 mg/day
      3. Suggested that US RDA (30 mg) may be too low
    2. References
      1. Meydani (1997) JAMA 277:1380-6 [PubMed]
  • Adverse Effects
  • Potential Risks or No Benefit
  1. Increased overall motality risk
    1. Associated with consistent dosing >400 IU/day for >1 year
  2. Does not reduce cancer risk
    1. Prostate Cancer risk is increased (1 new case in 625 men taking 400 units/day)
    2. Klein (2011) JAMA 306:1549-56. [PubMed]
  3. Congestive Heart Failure increased risk
  4. Coronary Artery Disease risk
    1. Initial studies suggested possible benefit
    2. PPP Study suggests no benefit
    3. May increase Heart Failure risk
    4. PPP study shows possibly higher CVA risk
    5. Studies show slightly higher all cause mortality
  5. Increased risk of bleeding and Hemorrhagic Stroke
    1. Interference with Vitamin K metabolism, Antagonizing Vitamin K dependent Clotting Factors
    2. Interference with Platelet aggregation
    3. Do not use >800 IU/day in patients on Warfarin or antiplatelet agents
    4. Schurks (2010) BMJ 341: c5702 [PubMed]
  • References
  1. (2011) Presc Lett 18(12): 68
  2. (2014) Presc Lett 21(2):12
  3. Stephans (1996) Lancet 347:781 [PubMed]
  4. (2001) Lancet 357:89-95 [PubMed]
  5. Lonn (2005) JAMA 293:1338-47 [PubMed]