<Tr> <Td> Vitamin B </Td> <Td> cobalamin </Td> <Td> Deficiency results in a macrocytic anemia, elevated methylmalonic acid and homocysteine, peripheral neuropathy, memory loss and other cognitive deficits . It is most likely to occur among elderly people, as absorption through the gut declines with age; the autoimmune disease pernicious anemia is another common cause . It can also cause symptoms of mania and psychosis . In rare extreme cases, paralysis can result . </Td> </Tr> <P> Because water - soluble B vitamins are eliminated in the urine, taking large doses of certain B vitamins usually only produces transient side - effects . General side effects may include restlessness, nausea and insomnia . These side - effects are almost always caused by dietary supplements and not foodstuffs . </P> <Table> <Tr> <Th> Vitamin </Th> <Th> Name </Th> <Th> Tolerable Upper Intake Level (UL) </Th> <Th> Harmful effects </Th> </Tr> <Tr> <Td> Vitamin B </Td> <Td> thiamine </Td> <Td> None </Td> <Td> No known toxicity from oral intake . There are some reports of anaphylaxis caused by high - dose thiamin injections into the vein or muscle . However, the doses were greater than the quantity humans can physically absorb from oral intake . </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> riboflavin </Td> <Td> None . </Td> <Td> No evidence of toxicity based on limited human and animal studies . The only evidence of adverse effects associated with riboflavin comes from in vitro studies showing the production of reactive oxygen species (free radicals) when riboflavin was exposed to intense visible and UV light . </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> niacin </Td> <Td> U.S. UL = 35 mg as a dieatry supplement </Td> <Td> Intake of 3000 mg / day of nicotinamide and 1500 mg / day of nicotinic acid are associated with nausea, vomiting, and signs and symptoms of liver toxicity . Other effects may include glucose intolerance, and (reversible) ocular effects . Additionally, the nicotinic acid form may cause vasodilatory effects, also known as flushing, including redness of the skin, often accompanied by an itching, tingling, or mild burning sensation, which is also often accompanied by pruritus, headaches, and increased intracranial blood flow, and occasionally accompanied by pain . Medical practitioners prescribe recommended doses up to 2000 mg per day of niacin in either immediate - release or slow - release formats, to lower plasma triglycerides and low - density lipiprotein cholesterol . </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> pantothenic acid </Td> <Td> None </Td> <Td> No toxicity known </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> pyridoxine, pyridoxal, pyridoxamine </Td> <Td> U.S. UL = 100 mg / day; EU UL = 25 mg / day Main article: vitamin B6 § Side effects </Td> <Td> Main article: vitamin B6 § Side effects </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> biotin </Td> <Td> None </Td> <Td> No toxicity known </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> folic acid </Td> <Td> 1 mg / day </Td> <Td> Masks B deficiency, which can lead to permanent neurological damage </Td> </Tr> <Tr> <Td> Vitamin B </Td> <Td> cyanocobalamin </Td> <Td> None established . </Td> <Td> Skin and spinal lesions . Acne - like rash (causality is not conclusively established). </Td> </Tr> </Table> <Tr> <Th> Vitamin </Th> <Th> Name </Th> <Th> Tolerable Upper Intake Level (UL) </Th> <Th> Harmful effects </Th> </Tr>

What is the chemical name of vitamin b