Santé et Services sociaux Québec.

Previous page Text size

Vitamin C

Have you ever heard of scurvy, the disease that caused the deaths of 25 of Christopher Columbus’s men? Well, the deaths were caused by vitamin-C deficiency. Vitamin C plays an essential role in maintaining tissue integrity, helps immune functions, and acts as an antioxidant preventing several diseases.

Dietary Sources

People wrongly believe that vitamin C occurs only in oranges and other citrus fruit. Many other foods are excellent sources of vitamin C, such as red bell peppers, which contain more than oranges! A varied diet easily supplies all the vitamin C your body needs.

The following table presents the vitamin-C content of various foods.

Vitamin-C Content of Some Foods
Food Serving Vitamin C (mg)
Red bell pepper 125 mL (½ cup) 95
Strawberries 250 mL (1 cup) 85
Orange 1 medium 70
Orange juice 125 mL (½ cup) 60
Broccoli 125 mL (½ cup) 52
Brussels sprouts, cooked 125 mL (½ cup) 48
Grapefruit, pink ½ fruit 47
Cauliflower 125 mL (½ cup) 36
Cantaloupe 1/4 fruit 32
Tomato 1 medium 22
Asparagus 125 mL (½ cup) 19
Potato (baked) 1 small 15

Iron and Vitamin C: a Winning Combination

The absorption of nonheme iron is affected by a certain number of nutritional components. Some foods enhance absorption of nonheme iron when consumed at the same time. Examples of this are foods containing vitamin C, meat, fish, and poultry. When consumed at the same time as nonheme iron (that is, during the same meal), meat, poultry, fish, and foods high in vitamin C can increase iron absorption by up to four times.

Vitamin C and Flu/Colds

You often hear that there is a relationship between vitamin C and the flu. Indeed, vitamin C can reduce the severity of symptoms, but there is no evidence that a supplement can eliminate the risk of getting the flu. So, it’s not necessary to take supplements with an eye to prevention.

Despite the very strong popular belief that vitamin-C supplements can cure the common cold, the scientific evidence isn’t conclusive, so that we can’t confirm if vitamin-C supplements prevent colds. The good news, however, is that vitamin C is effective in reducing the length and severity of cold symptoms and the related complications. This vitamin can also shorten the illness’s duration by about half a day.

Dietary Reference Intakes

The recommended daily allowance (RDA) is 75 mg for women and 90 mg for men. Smokers require about 35 mg more vitamin C than nonsmokers: women smokers should get 110 mg a day and men smokers 125 mg a day.

Age Groups Vitamin-C Requirements (mg/day)
0–6 months 40
7–12 months 50
1–3 years 15
4–8 years 25
9–13 years 45
14–18 years 75
19 years or older 90
9–13 years 45
14–18 years 65
19 years or older 75
18 years or younger 80
19–50 years 85
18 years or younger 115
19–50 years 120

Overconsumption of vitamin C can cause various side effects, the most common of which are gastrointestinal problems and diarrhea. No tolerable upper intake level (UL) has been established for infants ages 0 to 12 months: their intake of vitamin C must therefore be exclusively dietary. The UL for adults is about 2000 mg a day.

This vitamin is very sensitive to heat, so that cooking reduces the amount present in food. Get the best of vitamin C by eating good, fresh fruit and vegetables.