Vitamin C is an essential nutrient and antioxidant that has been rumored to play a beneficial role in certain diseases and conditions as well as increase energy level. Current research does not support the ability of vitamin C supplements in increasing energy, but there is some speculation on the energy benefits of foods containing high amounts of the vitamin.
Vitamin C is a antioxidant with the main functions in the body is to act as an electron donor. Vitamin C is also involved in the enzymatic reactions that lead to the synthesis of collagen, neurotransmitters and some amino acids. Vitamin C has two active forms called ascorbic acid and dehydroascorbic acid. High levels of ascorbic acid will provide protection from damage in the eye, and aid in the functions of neutrophils and lipoproteins. It is often questioned whether vitamin C supplements reduces oxidative damage increasing energy.
Vitamin C and Energy
Published in the International Journal of Sports Medicine in 1997 written by authors Nieman et al, a study that compared immune response in marathon runners taking a 1,000 mg of vitamin C per day for eight days versus those taking a placebo for the same amount of time. According to blood tests drawn six hours after a two and a half hour treadmill ride no difference was found in between the groups. This research concluded that vitamin C has not proven to increase energy levels or performance in these marathon participants.
Vitamin C and Oxidative Damage
A randomized controlled trial published by Huang et al in the journal called "Cancer, Epidemiology, Biomarkers & Prevention" in 2000 looked at the affects vitamin C had on oxidative DNA damage in 184 healthy participants. Oxidative damage to the cells decreases energy level. The study concluded that there was no different in oxidative damage between the participants taking vitamin C versus a placebo. The authors do however believe less oxidative damage is associated with at least three daily servings of fruit and vegetables.
Vitamin C is found most often in fruits and vegetables. A easy method for knowing if a fruit is high in vitamin C is by the rate in which it browns after being cut. An orange does not brown easily, while an apple does turn brown a few minutes after being cut. This is due to the antioxidant properties of vitamin C. Foods high in vitamin C include papaya, strawberries, oranges, broccoli, sweet pepper, and potatoes. Cooking or prolonged storage decreases vitamin C content.
While vitamin C does not increase energy or prevent oxidative damage, it is still an essential water-soluble vitamin. Since it is water-soluble vitamin there is a very low chance of toxicity. The tolerable upper intake level for vitamin C is 2000 milligrams per day. One serving of high vitamin C fruit contains about 100 milligrams. Vitamin supplements range from 60 milligrams per serving to 1000 milligrams per serving.