Vitamins

Vitamin E

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Vitamin E, Alpha Tocopherol

  • Sources
  1. Vegetable Oil
    1. Corn oil
    2. Cottonseed oil
    3. Sunflower oil
    4. Soybean oil
  2. Wheat germ
  3. Fish liver oil
  4. Nuts
  • Mechanism
  1. Vegetable and Seed Oils: gamma-tocopherol
    1. Antioxidant
    2. Usual daily intake 15 IU/day
  2. Supplements: alpha-tocopherol
    1. Blocks antioxidant effect of natural foods
    2. May have pro-oxidant effect
      1. S Christen (1997) Proc Natl Acad Sci 64:3217 [PubMed]
  • 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]