The human body systems depend on iron to complete daily functions. Anemia is a condition when the body does not produce enough hemoglobin to meet its oxygen-carrying needs. Daily iron intake can help prevent and treat anemia. Eating certain foods alongside iron may alter its ability to be accessed and absorbed by the body. Vitamin C can combined with certain forms of iron to improve the chance of iron absorption.Interested in losing weight? Learn more about LIVESTRONG.COM's nutrition and fitness program!
Iron is available in heme and non-heme forms. Heme iron is found in animal products such as liver, oysters, clams and other meats. Non-heme iron is found in plant based foods such as green leafy vegetables, fruits and nuts. According to S.R. Lynch and J.D. Cook, heme iron is more easily absorbed since is derived from animal hemoglobin and muscle tissue. Absorption of heme iron is usually independent of other substances eaten and will not be affected by vitamins. Non-heme iron is much harder to absorb but can be directly influenced by vitamin C intake.
Eating food high in iron does not guarantee adequate iron absorption. Heme iron is more easily absorbed but may be avoided by those with religious beliefs or special dietary needs. The International Journal for Vitamin and Nutrition Research has published multiple studies supporting the supplementation of vitamin C with dietary iron to increase the bioavailability of non-heme iron. The amount of absorption is direction proportionate to the amount of vitamin C taken.
Mixing vitamins and minerals together can often increase or decrease the body's ability to absorb nutrients. Vitamins and minerals that improve absorption when combined together are said to have synergistic effects. Vitamin C positively effects the absorption rate of non-heme iron. A 2004 study by Teucher et al. suggests that a minimum of 1 g of vitamin C should be combined with 3 mg of iron for increased absorption. Vitamin C enhances absorption by binding to non-heme iron and allowing for travel to the intestines.
Vitamin C helps with the transport and absorption of non-heme iron to the duodenum. Vitamin C is ascorbic acid. When ascorbic acid binds to the iron, it increases the stability of the compound. Non-heme iron becomes more stable and has increased solubility. Non-heme iron combined with ascorbic acid is more readily absorbed through the mucus membranes of the intestine.
According to Hallberg et al., eating and drinking tea and coffee can decrease the absorption of iron. Vitamin C can help reverse this process but cannot prevent it. Too much iron supplementation or iron and vitamin C supplementation can cause iron overdose. Side of effects of regular iron use can cause cramping, nausea and constipation. Consult a health care provider before increasing iron intake.