Riboflavin, or vitamin B2, is quite ubiquitous in the food supply—most people have no problem getting it. You’ll see it simply as riboflavin or riboflavin 5’-monophosphate in supplements. The RDA for adults is 1.1 milligram/day in females and 1.3 milligram/day in males. Measurements occur via enzyme and cellular tests, as well as through urinary riboflavin excretion.


  • The coenzyme function of B2 refers to its necessity as a precursor to coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN)
  • FAD and FMN are heavily involved as electron carriers in energy production and many metabolic pathways
  • Involved in the metabolism of folate, vitamin A, niacin, B6, and vitamin K
  • Component of neurotransmitter metabolism

Primary deficiency symptoms and diseases

  • Ariboflavinosis – red itchy eyes, night blindness, and cataracts; migraines; peripheral neuropathy; anemia (secondary to interference with iron absorption); fatigue; malignancy (esophageal and cervical dysplasia)
  • Deficiency linked to preeclampsia in pregnant women
  • No known toxicity

Food sources

  • Liver
  • Mushrooms
  • Dairy
  • Tomatoes
  • Spinach
  • Light exposure destroys B2


Most people will never need to supplement with riboflavin since it is so common in the food supply and quite easy to get on most diets in adequate amounts. Usually, heavy consumption of alcohol depletes B vitamin stores in the body and calls for a supplement, and it is also common in the B-complex supplements.

  • Riboflavin (most common)
  • Riboflavin 5'-monophosphate

Who needs it most?

  • Those who consume alcohol frequently
  • Trauma victims
  • Those with hypermetabolic conditions