Vitamin C

Vitamin C is a potent reducing agent in mammals and plants. Humans rely on vitamin C for the activity of numerous enzymes, and vitamin C status impacts physiological health, including risk for infections, cardiovascular disease, and cancer. The recommended intake for vitamin C in adults varies by gender and by country (from 45 to 110mg/d). The Tolerable Upper Intake Level is 2000mg/d. Supplemental vitamin C should not replace high intakes of fruits and vegetables, but it may offer health benefits under certain circumstances. Low intake of fruits and vegetables increases risk for scurvy, a concern for isolated populations, refugees, the critically ill, and the elderly. Smokers and patient populations are also at risk for suboptimal vitamin C status. Current vitamin C deficiency rates in developed countries range from 8% to 19%. Individuals with a history of renal stone formation or conditions associated with iron overload should use caution when supplementing with vitamin C.