Vitamin C, also known as ascorbic acid, is perhaps the most well known vitamin, commonly supplemented for its immune-boosting and antioxidant properties. It is water soluble and therefore generally easy to digest and absorb, although it can contribute to acid reflux in sensitive people.
In addition to vitamin C’s ability to reduce the duration of the common cold, it is also important for collagen formation, energy metabolism (via its role in L-Carnitine biosynthesis) and neurotransmitter production and also appears to play a role in cardiovascular health, reducing stress and depression as well as protecting our neurones from damage. Many people also use vitamin C for its anti-cancer benefits but these are still poorly established. Vitamin C is also involved in increasing iron absorption from foods and may thus be useful for preventing anaemia.
Vitamin C deficiency is relatively uncommon due to its natural presence in regularly consumed foods such as fruits and fruit juice and potato skin. The recommended daily intake for vitamin C is 80mg but studies show intakes of 2000mg to be more than safe when taken short term. Vitamin C easily oxidises and degrades, so it is important to eat fruit and vegetables fresh, as soon as possible after picking to ensure a good vitamin C level is still present.
Vitamin C comes in many forms and any of the following compounds could be labelled as vitamin C on a supplement or food product: L-Ascorbic Acid (actual vitamin C), Sodium-L-Ascorbate, Potassium-L-Ascorbate, Calcium-L-Ascorbate and L-Ascorbyl-6-Palmitate. All forms are equally able to elicit biological effects with the exception of DNA oxidation where L-Ascorbyl-6-Palmitate is the only form that appears to protect DNA from oxidative damage.
In general, ascorbic acid is the best option for those wishing to take a supplement as it has proven effectivity and is very economical. Choosing natural forms of vitamin C, such as from dietary sources and derived from foods, will help enhance the bioavailability and absorption because of the presence of other substances including bioflavonoids and vitamin C metabolites that enhance the uptake of the vitamin.