Importance Of Vitamin C In Citrus Fruits

You cannot make the vitamin C that you need for good health, so you need to consume it every day. Citrus fruits are an excellent source of vitamin C, according to the U.S. Office of Dietary Supplements. In fact, all you really need is an orange a day. Such fruits are also a good source of vitamin B1, thiamine, potassium and folic acid.

Identification

A top source of vitamin C is fruits and vegetables, and citrus fruits are one of the major contributors of this nutrient to the American diet, according to the Office of Dietary Supplements. When you drink ¾ cup orange juice, for example, you get 155 percent of the vitamin C needed in a day. A medium orange gives you 117 percent, while half a medium grapefruit gives you 65 percent.

Types

Oranges are a top source of vitamin C among citrus fruits. They provide 40 to 70 mg vitamin C per 100 ml of juice. Grapefruits, tangerines and lemons give you 20 to 50 mg per 100 ml of juice, according to Milind S. Ladaniya, author of "Citrus Fruit: Biology, Technology and Evaluation." Vitamin C also exists in the fruit's peel. In an orange, for example 25 percent of the fruit's vitamin C content exists in the juice. In a grapefruit, 17 percent of the content is in the juice.

Significance

Vitamin C is an important antioxidant. It helps protect your body against damage by free radicals. Free radicals are generated in your body during normal metabolism and also via exposure to pollutants and toxins like cigarette smoke, according to Oregon State University. Damage from free radicals may lead to cancer, according to the National Cancer Institute. The flavonoids in citrus fruit also may protect against cancer, according to Laura A. de la Rosa, lead author for the book "Fruit and Vegetable Phytochemicals."

Function

Your body needs vitamin C to create collagen--the important structural component of tendons, ligaments and blood vessels and required for healthy brain function, for fat metabolism and for cholesterol metabolism, according to Oregon State University. If you lack vitamin C you can contract the potentially fatal disease called scurvy, which is characterized by hair and tooth loss, bleeding and bruising easily and joint pain. These symptoms are due to weakening of blood vessels and connective tissue, which contain collagen. Vitamin C also affects your immune system.

Expert Insight

Citrus juice gives you higher amounts of vitamins, including C, than other foods on a per-calorie basis, notes Ladaniya. This is true for other vitamins as well, including vitamin A, niacin and thiamin. However, if you don't like citrus fruits, don't worry. There is no difference in your body's ability to absorb and use vitamin C from citrus fruits versus vitamin C supplements, according to J.F. Gregory, author of a study published in the journal "Nutrition Reviews." Synthetic and natural vitamin C are chemically identical, notes Oregon State University.