Vitamin B2

Riboflavin

Sample of microcrystaline riboflavin
Clinical data
Trade names	many
AHFS/Drugs.com	Monograph
Pregnancy category	US: A (No risk in human studies) and C
Routes of administration	by mouth, IM, IV
ATC code	A11HA04 (WHO)
Legal status
Legal status	US: OTC
Pharmacokinetic data
Excretion	Urine
Identifiers
IUPAC name 7,8-Dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo[g]pteridine-2,4-dione
Synonyms	vactochrome, lactoflavin, vitamin G
CAS Number	83-88-5
PubChem CID	493570
IUPHAR/BPS	6578
DrugBank	DB00140
ChemSpider	431981
UNII	TLM2976OFR
KEGG	D00050
ChEBI	CHEBI:17015
ChEMBL	CHEMBL1534
E number	E101 (colours)
ECHA InfoCard	100.001.370
Chemical and physical data
Formula	C17H20N4O6
Molar mass	376.37 g·mol−1
3D model (Jmol)	Interactive image
SMILES O=C2/N=C\1/N(c3cc(c(cc3/N=C/1C(=O)N2)C)C)C[C@H](O)[C@H](O)[C@H](O)CO
InChI InChI=InChI=1S/C17H20N4O6/c1-7-3-9-10(4-8(7)2)21(5-11(23)14(25)12(24)6-22)15-13(18-9)16(26)20-17(27)19-15/h3-4,11-12,14,22-25H,5-6H2,1-2H3,(H,20,26,27)/t11-,12+,14-/m0/s1  N Key:AUNGANRZJHBGPY-SCRDCRAPSA-N

Riboflavin, also known as vitamin B₂, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to prevent and treat riboflavin deficiency and prevent migraines. It may be given by mouth or injection.

It is nearly always well tolerated. Normal doses are safe during pregnancy. Riboflavin is in the vitamin B group. It is required by the body for cellular respiration. Food sources include eggs, green vegetables, milk, and meat.

Riboflavin was discovered in 1920, isolated in 1933, and first made in 1935. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Riboflavin is available as a generic medication and over the counter. In the United States a month of supplements costs less than 25 USD. Some countries require its addition to grains.

Riboflavin has been used in several clinical and therapeutic situations. For over 30 years, riboflavin supplements have been used as part of the phototherapy treatment of neonatal jaundice. The light used to irradiate the infants breaks down not only bilirubin, the toxin causing the jaundice, but also the naturally occurring riboflavin within the infant's blood, so extra supplementation is necessary.

One clinical trial found that high-dose riboflavin appears to be useful alone or along with beta-blockers in the prevention of migraine. A dose of 400 mg daily has been used effectively in the prophylaxis of migraines, especially in combination with a daily supplement of magnesium citrate 500 mg and, in some cases, a supplement of coenzyme Q10. However, two other clinical studies have failed to find any significant results for the effectiveness of B2 as a treatment for migraine.