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 B3 paresthesia, and headache. Liver toxicity is the most serious toxic reaction and it occurs at doses >2 grams/day. Fulminant hepatitis has been reported at doses between 3-9 grams/day with needs for liver transplantation. Other reactions include: Vitamin B deficiency can cause pellagra, a disease found in many alcoholics in North America. Symptoms include vomiting, loss of appetite, abdominal pain, and general fatigue. Vitamin B3 Vitamin B is a vitamin that includes three forms: nicotinamide (niacinamide), niacin (nicotinic acid), and nicotinamide riboside. All three forms of vitamin B are converted within the body to nicotinamide adenine dinucleotide (NAD). NAD is required