What it does in the body
- Collagen synthesis (essential cofactor for prolyl and lysyl hydroxylases)
- Antioxidant defense (primary aqueous-phase free radical scavenger)
- Non-heme iron absorption enhancement (reduces Fe3+ to Fe2+ in the gut)
- Carnitine synthesis (required for fatty acid transport into mitochondria)
- Neurotransmitter synthesis (dopamine beta-hydroxylase cofactor for norepinephrine)
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | 90 mg | NIH/IOM |
| Adult female | 75 mg | NIH/IOM |
| Pregnancy | 85 mg | WHO/IOM |
| Children | 15-45 mg (ages 1-13) | WHO |
| Older adults | 90 mg (male), 75 mg (female); smokers add 35 mg/day | NIH |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Kakadu plum (Terminalia ferdinandiana) | 2300-3150 mg per 100g | Australia (Aboriginal) |
| Camu camu | 2400 mg per 100g | South America (Amazon) |
| Guava | 228 mg per 100g | Tropics/Central America |
| Red bell pepper | 128 mg per 100g | global |
| Kiwifruit | 93 mg per 100g | New Zealand/global |
| Orange | 53 mg per 100g | global |
| Broccoli (cooked) | 65 mg per 100g | global |
| Indian gooseberry (Amla) | 600 mg per 100g | South Asia |
In our food database, per 100 g
Highest among our free foods — open the Food Explorer to compare.
If you don't get enough
Mild: Fatigue, irritability, poor wound healing, easy bruising
Moderate: Perifollicular hemorrhage, corkscrew hairs, gingival inflammation and bleeding, arthralgia
Severe: Scurvy: spontaneous hemorrhage, tooth loss, anemia, bone pain, impaired wound healing, death if untreated
Time to onset: Plasma levels decline within 1-3 weeks without intake; clinical scurvy in 1-3 months of total vitamin C deprivation
Too much
Upper limit: 2000 mg/day for adults
GI distress (nausea, diarrhea, cramping) at >2g/day. Increased oxalate production with risk of kidney stones in susceptible individuals. False negative fecal occult blood test. In G6PD deficiency, high IV doses can cause hemolysis.
How well you absorb it
~70-90% at moderate intakes (30-180 mg); decreases to ~50% at 1000 mg; <16% at 12,000 mg due to saturated SVCT1 transport
Helped by: Consuming with food, Organic acids in fruits, Divided doses throughout the day
Hindered by: Smoking (increases turnover by 40%), Aspirin (competes for absorption), Heat and oxidation during cooking, Alkaline cooking conditions
Cooking & storage
Vitamin C is the most heat-sensitive and water-soluble vitamin. Boiling destroys 50-75% of vitamin C. Steaming retains 80-90%. Cutting and exposing to air oxidizes vitamin C. Cooking in copper pots accelerates destruction. Best consumed raw when possible.
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
