The Powerhouse Antioxidant Vitamin
Vitamin C (ascorbic acid) is a water-soluble antioxidant essential for collagen synthesis, immune function, and iron absorption. The FDA Daily Value is 90mg per day (slightly higher for smokers: 125mg).
Unlike most animals, humans cannot synthesize vitamin C — we must obtain it entirely through diet. The good news: a single serving of red bell pepper provides more than the entire daily requirement.
Top Vitamin C Foods (Per 100g, USDA Data)
| Food | Vitamin C (mg/100g) |
|---|---|
| Red bell pepper (raw) | 128 |
| Guava | 228 |
| Kiwifruit | 92.7 |
| Broccoli (raw) | 89.2 |
| Brussels sprouts (raw) | 85.0 |
| Strawberries | 58.8 |
| Orange | 53.2 |
| Lemon juice | 38.7 |
Guava is one of the highest natural sources — one fruit (~55g) provides more than the full DV.
🍊 View full vitamin C ranking →Heat Destroys Vitamin C — Eat Raw When Possible
🌡️ Cooking reduces vitamin C by 15–55%
Vitamin C is heat-labile. Boiling vegetables loses the most; steaming and microwaving preserve significantly more. Roasting bell peppers loses ~25%.
💧 Water-soluble — leaches into cooking water
When boiling vegetables, much of the vitamin C dissolves into the water. Use stir-frying or steaming instead, or use the cooking liquid in soups.
🍊 Vitamin C enhances iron absorption
Adding vitamin C to plant-based iron sources can increase non-heme iron absorption by 2–3×. Try lemon juice on spinach or bell peppers in lentil dishes.
Key Takeaways
- ✓Red bell peppers have more vitamin C than oranges — one cup provides 190% DV
- ✓Guava and kiwi are among the highest vitamin C fruits by weight
- ✓Raw vegetables retain more vitamin C than cooked ones
- ✓Steaming and microwaving preserve more vitamin C than boiling
- ✓Use vitamin C-rich foods to boost iron absorption from plant sources
Data Source
USDA FoodData Central — Foundation Foods & SR Legacy (Public Domain)