High levels of vitamin C can mostly be found in the cells and tissues of your body, such as white blood cells, the eyes, adrenal glands, pituitary gland and the brain.
However, the human body is not capable of producing vitamin C on its own, and therefore needs the vitamin to be supplemented as part of a healthy and balanced diet. The most common source of vitamin C are fruits and vegetables. It is worth noting that vitamin C is the most fragile of all vitamins, and can therefore be damaged through prolonged storage or overcooking. Heat, exposure to air and solubility to water are some of the conditions which can denature the vitamin C of a food source. For example, the vitamin C content of a citrus fruit can be halved in 24 hours if left exposed to air or stored in a place with high temperatures. Thus, in order for your body to absorb vitamin C effectively, it is recommended for you to eat fruits and vegetables raw instead of serving them as part of a cooked dish.