Vitamins Contained In Onions

Red, white, yellow and sweet -- there are a variety of onions available on supermarket shelves. Most people either love onions or hate them, because their flavor is strong and their smell is stronger. Whatever type is your favorite, onions are nutritionally beneficial and contain fiber, protein and minerals. They also deliver numerous vitamins that benefit overall health.

Vitamin C

The U.S. Department of Agriculture National Nutrient Database reports that a 1-cup cup serving of chopped raw onion contains 11.8 mg of vitamin C, or 20 percent of the recommended daily intake, or RDI. Vitamin C is an antioxidant vitamin, which means it helps fight DNA damage caused by free radicals that can lead to chronic diseases such as cardiovascular disease or cancer. Other benefits of vitamin C include boosting the immune system, reducing blood pressure and reducing the risk of stroke and gout. According to the Linus Pauling Institute, even a small amount of vitamin C is beneficial in protecting the body from free radical damage. Vitamin C is a water-soluble vitamin, which means your body does not store it so you need to replace it daily.

Vitamin B6

Vitamin B6 is also known as pyridoxine. A member of the B complex family, B6 helps metabolize food, prevent inflammation and maintain healthy eyes, skin and hair. According to the University of Maryland Medical Center, B6 also affects the nervous system as it assists with the production of neurotransmitters that affect mood. A 1-cup serving of raw chopped onion contains 0.2 mg of B6, or 10 percent of the RDI. B6 is also a water-soluble vitamin.

Folate

Folate is another member of the water-soluble B complex family of vitamins. Folate is a B vitamin that is especially important during pregnancy because it aids in the production of new blood cells during times of rapid cell turnover. According to a report in the February 2011 issue of the "Journal of Inherited Metabolic Disease," people with low folate levels are at higher risk for the development and spread of various forms of cancer. However, some studies suggest that taking excessive levels of folic acid, the synthetic form of folate, can actually increase cancer risk, while dietary folate can reduce the risk of cancer. A 1-cup serving of chopped onion contains 30.4 micrograms of folate, or 8 percent of the RDI.

Other Vitamins

Onions offer several other vitamins in smaller amounts. Other members of the B family, including thiamin, riboflavin, pantothenic acid and niacin round out the B content of onions. Traces of vitamins A and K are also present. While the vitamin content of onions may seem small, adding them to your foods, salads and sandwiches help you reach 100 percent of your recommended daily vitamin intake.