Vitamin C Intake Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/5/2026
The percentage of recommended vitamin C intake is calculated with (vitamin C consumed ÷ RDA) × 100. The French ANSES RDA is 110 mg/day for a non-smoking adult, and at least 120 mg/day for a smoker; with 80 mg consumed, a non-smoker reaches about 73% of their RDA.
Explanation
Vitamin C (ascorbic acid) plays a role in many bodily functions: collagen synthesis, absorption of non-heme iron from plant sources (see our iron intake calculator), and antioxidant defense against oxidative stress. The recommended daily intake set by France's food safety agency (ANSES) is 110 mg per day for a healthy non-smoking adult. Smokers have increased needs, generally estimated at at least 120 mg per day and potentially more depending on smoking intensity: burning tobacco generates significant oxidative stress in the body, which speeds up the breakdown of vitamin C and therefore increases the amount needed to maintain a nutritional status equivalent to a non-smoker's. Contrary to a persistent misconception, oranges and citrus fruits aren't the richest source of vitamin C: red bell pepper, fresh parsley, kiwi, broccoli, and blackcurrant often contain more per serving. Vitamin C is also particularly sensitive to heat and oxidation: prolonged cooking or long storage of fruits and vegetables noticeably reduces their actual content compared to eating them raw and fresh. This calculator gives an estimate based on reported dietary intake, without accounting for any supplementation.
Example: non-smoker, 80 mg of vitamin C consumed
Inputs
Vitamin C consumed: 80 mg. Status: non-smoker (RDA 110 mg/day).
Calculation
Percentage of RDA = (80 ÷ 110) × 100 ≈ 72.73%.
Result
This intake covers about 73% of the recommended vitamin C intake for this profile.
Frequently asked questions
Why do smokers need more vitamin C?
Because burning tobacco generates significant oxidative stress in the body, which uses up and breaks down available vitamin C faster. To maintain a nutritional status equivalent to a non-smoker's, a higher intake is therefore recommended — one more reason, among many others, to consider quitting smoking as beneficial for overall nutritional balance.
What foods are richest in vitamin C, beyond citrus fruits?
Raw red bell pepper, fresh parsley, kiwi, broccoli, blackcurrant, and Brussels sprouts are among the richest sources, often surpassing oranges per equivalent serving. Since vitamin C is heat-sensitive, eating produce raw or lightly cooked better preserves its actual content.
Is too much vitamin C dangerous?
Through diet alone, an excess remains very unlikely, since vitamin C is water-soluble (the body eliminates the surplus in urine rather than storing it). Very high-dose supplementation, however, can cause digestive issues (notably diarrhea) beyond certain thresholds; the European Food Safety Authority (EFSA) hasn't set a strict safety limit for adults, but prolonged high-dose supplementation is worth discussing with a healthcare professional.