Scurvy on a diet devoid or nearly devoid of vitamin C, had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy, and in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day. The vast majority of animals and plants are able to synthesize vitamin C, through a sequence of enzyme-driven steps, which convert monosaccharides to vitamin C. However, some mammals have lost the ability to synthesize vitamin C, notably simians and tarsiers.
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