Vitamin C

Vitamin C is a water-soluble vitamin and it is involved in more than 300 processes in the body.

Vitamin C RDA (Recommended Dietary Allowance):

• Adults (19+ years): 90 mg/day (men), 75 mg/day (women)
• Pregnant women: 85 mg/day
• Breastfeeding women: 120 mg/day
• Smokers: Additional 35 mg/day

ODA (Optimal Daily Allowance):

• 200-1,000 mg/day (varies depending on individual needs and health goals)

Found in:

• Citrus fruits (oranges, lemons, grapefruits)
• Berries (strawberries, raspberries)
• Kiwi
• Papaya
• Pineapple
• Bell peppers (especially red)
• Broccoli
• Brussels sprouts
• Spinach and kale

Helps with:

• Collagen synthesis (important for skin, cartilage, and blood vessels)
• Antioxidant properties (neutralizing free radicals)
• Immune system support
• Wound healing
• Enhancing iron absorption from plant-based foods
• Reducing risk of chronic diseases (e.g., heart disease)

Insufficient doses:

• Symptoms of deficiency:
  • Fatigue and weakness
  • Irritability
  • Joint and muscle pain
  • Dry skin and hair
  • Slow wound healing
  • Bleeding gums and tooth loss
• Severe deficiency can lead to scurvy, characterized by swollen gums, easy bruising, anemia, and skin issues.

Excessive doses:

• Vitamin C is generally considered safe up to 2,000 mg/day (tolerable upper intake level)
• Possible side effects of high doses:
  • Stomach upset and diarrhea
  • Nausea
  • Increased risk of kidney stones (especially in individuals prone to oxalate stones)

Interactions:

• Synergy:
  • Vitamin C works well with vitamin A and vitamin E (enhances antioxidant activity by regenerating oxidized vitamin E).
  • Improves absorption of non-heme iron from plant-based sources.
  • Synergistic effects with zinc for immune health.
• Antagonistic interactions:
  • High doses may interfere with certain laboratory tests (e.g., blood glucose measurements).
  • Large doses may reduce the effectiveness of chemotherapy or radiation in cancer treatments (consult a healthcare provider).
  • May decrease vitamin B12 absorption if taken in extremely high doses over long periods.