Vitamin B2 (Riboflavin)
water-soluble
Key Takeaways
- Precursor to coenzymes FMN and FAD, required by 90+ flavoproteins
- Plays roles in citric acid cycle, beta-oxidation, and amino acid metabolism
- Emerging evidence supports use in migraine prophylaxis in adults
- FDA daily value is 1.3 mg
- Required for biosynthesis of CoA, CoQ, heme, and pyridoxal 5-phosphate
Evidence Spectrum
15 studies reviewed →Role in the Body
Vitamin B2 (riboflavin) is an essential dietary compound used for the enzymatic biosynthesis of FMN and FAD. The human genome contains 90 genes encoding flavin-dependent proteins (pmid:23500531). The majority catalyze oxidation-reduction reactions in the citric acid cycle, beta-oxidation, and amino acid degradation. Riboflavin also has neuroprotective properties, inhibiting glutamate release from synaptosomes (pmid:34477538).
- Precursor to FMN and FAD coenzymes
- Required for citric acid cycle and beta-oxidation
- Biosynthesis of CoA, CoQ, heme, pyridoxal 5-phosphate
- Neuroprotective via glutamate modulation
Supplement Forms
Riboflavin (free form)
RecommendedBioavailability: 0.6%
Standard supplement; absorption saturates ~27 mg/dose
Riboflavin 5-phosphate (FMN)
RecommendedBioavailability: 0.6%
Active coenzyme form
Food Sources
Dairy products
Eggs
Lean meats
Fortified cereals
Almonds
Mushrooms
Spinach
Deficiency
Prevalence: Uncommon in developed countries due to fortification; concern in dairy-limited diets.
Symptoms:
- Angular cheilitis
- Glossitis
- Seborrheic dermatitis
- Sore throat
- Photophobia
Risk Factors:
- Vegan/dairy-free diets
- Chronic alcoholism
- Elderly with poor intake
Safety & Interactions
Possible Side Effects:
- • Well tolerated; bright yellow urine at high doses (pmid:26780280)
Drug Interactions:
- • Required for B6 activation to pyridoxal 5-phosphate
- • Involved in folate metabolism
Contraindications:
- • No known contraindications
Frequently Asked Questions
What does B2 do?
Precursor to FMN/FAD coenzymes required by 90+ flavoproteins for energy, fat oxidation, and cofactor synthesis.
Can B2 help migraines?
Evidence suggests 200-400 mg/day reduces migraine frequency in adults.
Research Sources
15 peer-reviewed studies analyzed from PubMed. 4 directly cited in this review.