Vitamin C contributing to the more severe symptoms of scurvy. More generally, the biochemical role of vitamin C is to act as an antioxidant (a reducing agent) by donating electrons to various enzymatic and non-enzymatic reactions. Doing so converts vitamin C to an oxidized state - either as semidehydroascorbic acid or dehydroascorbic acid. These compounds can be restored to a reduced state by glutathione and NADPH-dependent enzymatic mechanisms. In plants, vitamin C is a substrate for ascorbate peroxidase. This enzyme utilizes ascorbate to neutralize toxic hydrogen peroxide (HO) by converting it to water (HO). Scurvy is a disease resulting from a deficiency
Vitamin B12 deficiency Vitamin B12 deficiency Vitamin B deficiency, also known as cobalamin deficiency, is the medical condition of low blood levels of vitamin B. In mild deficiency a person may feel tired and have a reduced number of red blood cells (anemia). In moderate deficiency there may be inflammation of the tongue and the beginning of neurological problems including abnormal sensations such as "pins and needles", while severe deficiency may include reduced heart function and greater neurological problems. Neurological problems may include changes in reflexes, poor muscle function, memory problems, decreased taste, and in extreme cases psychosis. Sometimes temporary infertility may also