Vitamins

Folic Acid

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Folic Acid, Vitamin B9, Folate, Folacin, Folic Acid Supplementation in Pregnancy

  • Indications
  • Supplementation
  1. Pregnancy
  2. Elevated Homocysteine levels
  3. Coronary Artery Disease prevention (disproven)
  • Physiology
  1. Folate needed to convert Homocysteine to methionine
  2. Lowers Homocysteine levels (but does not appear to lower CAD risk)
  • Preparations
  • 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)
  • 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 (not recommended)
    1. Folate 400 ug to 5 mg (depending on Homocysteine)
    2. Not recommended due to low efficacy (lowers Homocysteine but not CAD risk)
  • Dosing
  • Pregnancy
  1. General population
    1. Folate 400 mcg daily (as found in Prenatal Vitamins)
    2. Start at least 1 month before conception
    3. Continue for at least first 3 months of pregnancy (12 weeks postconceptions)
      1. Typically continued throughout pregnancy and Lactation
  2. Moderate risk
    1. Folic Acid 1000 mcg daily
      1. Start at least 3 months before conception and continue at least until 12 weeks post-conception
      2. Some guidelines recommend the 4000 to 5000 mcg dose as given to high risk patients (see below)
    2. Indications
      1. Insulin Dependent Diabetes Mellitus
      2. Seizure disorder or anticonvulsant use
      3. Obesity (BMI>35 kg/m2)
      4. Neural Tube DefectFamily History
  3. High risk
    1. Folic Acid 4000-5000 mcg daily
      1. Start at least 3 months before conception and continue at least until 12 weeks post-conception
    2. Indications
      1. Prior Neural Tube Defect
      2. Folic Acid antagonist use (e.g. Methotrexate)
      3. Prior delivery complicated by Folic Acid Deficiency associated birth defect
        1. Cleft Palate
        2. Congenital Heart Disease
        3. Limb defect
        4. Urinary tract anomaly
        5. Hydrocephalus
  • Signs
  • Deficiency
  • Pharmacokinetics
  1. Folate in supplements twice as bioavailable as food
  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 [PubMed]
    2. Malinow (1998) N Engl J Med 338:1009 [PubMed]