Vitamins

Vitamin C

search

Vitamin C, Ascorbic Acid

  • Sources
  1. Citrus fruits
    1. Orange Juice (8 ounces contains 100 mg)
    2. Lemons
    3. Grapefruit
  2. Dark-green leafy vegetables
    1. Asparagus
    2. Broccoli
  3. Tomatoes
  • Doses (Ascorbic Acid per day)
  1. Recommended Daily Allowance: 200 mg/day
  2. Minimum (Scurvy prevention)
    1. Formula fed infants: 35 mg/day
    2. Lactating mothers: 100 mg/day
    3. Other children and adults: 45-60 mg/day
  • Mechanism
  1. Essential Cofactor for hydroxylation of procollagen amino acids: Proline, Lysine
    1. Collagen's triple helix structure in connective tissue is reliant on procollagen hydroxylation
    2. When procollagen pathway is dysfunctional, Scurvy results (pupura, Petechiae, Gingival Bleeding)
  2. Contributes to hair disulfide bond formation
  3. Cofactor in carnitine and Norepinephrine biosynthesis
  4. Oxidative promotion of iron absorption
  5. Has both antioxidant and pro-oxidant effects
  • Effects
  1. Potential benefits of high intake
    1. Reduced risk of Senile Cataract
    2. Reduced risk of Cancer
    3. Reduced risk of Coronary Artery Disease
    4. Higher HDL Cholesterol concentrations
  2. Disproved Myths: non-benefits
    1. Does NOT prevent Upper Respiratory Infections
      1. Studied with short term studies
  • Adverse Effects
  • High doses of Vitamin C (>1 gram)
  1. Poorly absorbed
  2. Diarrhea
  3. Increased urinary oxylate excretion
    1. Nephrolithiasis risk
  • References
  1. Behrman (2000) Nelson Pediatrics, p. 182-4
  2. Rendon et al. (2017) Crit Dec Emerg Med 31(6): 15-21