Vitamin C, isolated and named more than 100 years ago, is crucial for good health. Even before it was discovered, vitamin C entered history. A lack of fresh fruits and vegetables on long sea voyages meant sailors were susceptible to scurvy. This sapped their energy and caused pain and shortness of breath. Bleeding gums made it difficult for them to eat the hardtack biscuits that were frequent fare. By the mid-18th century, James Lind of the Royal British Navy had figured out that a ration of citrus juice would prevent scurvy. Although it took decades before the navy implemented his findings, ultimately British sailors were issued lemon or lime juice, earning them the nickname “limeys.” But how much vitamin C do humans need?
How Much Vitamin C Should You Get?
Q. My dad can’t drink any citrus juice because it does not agree with him. He eats green vegetables, but not every day. Could he be low in vitamin C? If so, how much vitamin C should he take in a supplement?
A. The recommended dietary allowance (RDA) for vitamin C (ascorbic acid) is 90 mg for adult men and 75 mg for adult women. Smokers need more. So do women who are pregnant or breast feeding. (Here is the detailed breakdown.)
How Much Vitamin C Is in Your Diet?
According to the CDC, nearly 16 million Americans get too little vitamin C, less than 30 mg a day. Some experts suggest supplementing with 200 to 300 mg a day to be safe. Citrus foods are a wonderful source, but not everyone can tolerate them. Other foods high in vitamin C include bell peppers, kiwifruit, broccoli, strawberries and Brussels sprouts. Cantaloupe, cabbage and cauliflower also provide significant ascorbic acid.
Why You Need Vitamin C:
Vitamin C is critical for the immune system, skin and connective tissue and has anti-cancer activity. Vitamin C also promotes the absorption of nonheme iron from plant foods, and thus helps prevent iron deficiency anemia. The RDA may protect people from deficiency (scurvy) but may not be optimal for good health.
You can read more about unusual uses for vitamin C, such as to calm a cough due to asthma or to protect the stomach from damage caused by aspirin or other NSAIDs. Tell us about your experience using vitamin C supplements.