Folic Acid

1. See Also
   1. Folate Deficiency (causes Macrocytic Anemia)
   2. Serum Folate
2. Indications for supplementation
   1. Pregnancy
   2. Coronary Artery Disease prevention
   3. Elevated Homocysteine levels
3. Physiology
   1. Folate needed to convert Homocysteine to methionine
   2. May reduce CAD risk by lowering Homocysteine levels
4. Sources
   1. Meat
   2. Dark green leafy vegetables
      1. Spinach
      2. Romaine lettuce
   3. Dry beans
   4. Peanuts
   5. Wheat germ
   6. Yeast
   7. Enriched whole cereal grains (140 ug/100 grams grain)
5. Dosing
   1. General
      1. Typical U.S. intake: 50-500 ug/day
      2. Recommended Daily Allowance (RDA): 400 ug/day
   2. Coronary Artery Disease prevention
      1. Folate 400 ug to 5 mg (depending on Homocysteine)
   3. Pregnancy
      1. General population
         1. Folate 400 ug qd (as found in Prenatal Vitamins)
         2. Start at least 1 month before conception
         3. Continue for at least first 3 months of pregnancy
      2. High risk populations
         1. Indications
            1. Diabetes Mellitus
            2. Seizure disorder or anticonvulsant use
         2. Dose
            1. Folate 1 mg qd from >1 month before conception
      3. Prior Neural Tube Defect
         1. Folate 4 mg qd from >1 month before conception
6. Signs of Deficiency
   1. See Folic Acid Deficiency
7. Pharmacokinetics
   1. Folate in supplements twice as bioavailable as food
8. Efficacy: Pregnancy
   1. At conception, reduces Neural Tube Defects by 50%
      1. Spina bifida
      2. Anencephaly
      3. Czeizel (1992) N Engl J Med 327:1832
   2. Reduced fetal risk of Cleft Lip and Palate by 25-50%
      1. Lancet (1995) 346:393
   3. Reduces Conotruncal heart defects by 43%
      1. Transposition of the Great Vessels
      2. Tetralogy of Fallot
      3. Botto (1996) Pediatrics 98:911-7
9. Efficacy: Coronary Artery Disease
   1. Possible Protective against cardiovascular disease
      1. Low intake associated with higher Homocysteine levels
      2. Higher Homocysteine levels associated with CAD, CVA
   2. References
      1. Boushey (1995) JAMA 274:1049
      2. Malinow (1998) N Engl J Med 338:1009