II. Preparations: Dietary Sources
- Citrus fruits
- Orange Juice (8 ounces contains 100 mg)
- Lemons
- Grapefruit
- Dark-green leafy vegetables
- Asparagus
- Broccoli
- Tomatoes
III. Dosing (Ascorbic Acid per day)
- Recommended Daily Allowance: 200 mg/day
- Minimum (Scurvy prevention)
- Formula fed infants: 35 mg/day
- Lactating mothers: 100 mg/day
- Other children and adults: 45-60 mg/day
IV. Mechanism
- Key role of Vitamin C is in keeping iron reduced in hydroxylase enzymes
- Essential Cofactor for hydroxylation of procollagen Amino Acids: Proline, Lysine
- Tyrosine, as well as Phenylalanine, are converted to homogenistic acid via enzyme with Vitamin C
- Contributes to hair disulfide bond formation
-
Cofactor in Norepinephrine biosynthesis (from Dopamine)
- Adrenal Gland has among the highest Vitamin C concentrations in the body
- Cofactor in carnitine biosythesis
- Oxidative promotion of iron absorption
- Has both antioxidant and pro-Oxidant effects
V. Effects
- Potential benefits of high intake
- Reduced risk of Senile Cataract
- Reduced risk of Cancer
- Reduced risk of Coronary Artery Disease
- Higher HDL Cholesterol concentrations
- Disproved Myths: non-benefits
- Does NOT prevent Upper Respiratory Infections
- Studied with short term studies
- Does NOT prevent Upper Respiratory Infections
VI. Adverse Effects: High doses of Vitamin C (>1 gram)
- Poorly absorbed
- Diarrhea
- Increased urinary oxylate excretion
- Nephrolithiasis risk
VII. References
- Behrman (2000) Nelson Pediatrics, p. 182-4
- Rendon et al. (2017) Crit Dec Emerg Med 31(6): 15-21