Riboflavin

Riboflavin is a Vitamin supplement available in 1 form.

Not all forms of Riboflavin are equal. The form you choose determines how much Riboflavin actually reaches your tissues, and the difference between the best and worst forms can be substantial. Riboflavin-5'-phosphate (R5P) is the coenzyme, active form of vitamin B2 (riboflavin) that is directly usable by the body without requiring the phosphorylation step needed to convert unactivated riboflavin. As an S1-tier B2 form, research supports R5P for promoting healthy FAD/FMN coenzyme activity in energy metabolism, antioxidant function, and mitochondrial electron transport.

Vitamin B2 (as Riboflavin-5-Phosphate) Preferred (Preferred Form) has a bioavailability rating of good absorption. Typical dose range: not yet documented in our database.

Riboflavin-5-phosphate (R5P) is the active coenzyme form of vitamin B2, bypassing the liver conversion step required by standard riboflavin. It serves as a cofactor for flavoenzymes including MTHFR (critical for methylation) and glutathione reductase (antioxidant recycling). The phosphorylated form is preferred for individuals with impaired flavin kinase activity.

Riboflavin absorption occurs via a saturable carrier-mediated process in the upper GI tract; a gastroretentive device significantly elevated riboflavin bioavailability by extending residence in the narrow absorption window. PMID: 16806558

A human study characterizing the absorption, metabolism, and excretion of orally administered riboflavin-5'-phosphate (FMN). PMID: 6030496

Riboflavin administered orally as 5'-phosphate flavin mononucleotide behaved as an actively-transported compound with measurable absorption kinetics in controls and quadriplegic patients. PMID: 4004520

Vitamin B2 (as Riboflavin-5-Phosphate) is classified as Preferred Form by FormulaForge — our top recommendation for Riboflavin. It carries a bioavailability rating of good absorption, meaning more of the active compound reaches your tissues per dose unit compared to lower-rated forms.

When choosing a Riboflavin supplement, look for the S1 (best absorption) bioavailability tier on the label. Preferred Forms have the strongest research-backed evidence for efficient absorption.

Other forms may be appropriate depending on individual goals, cost considerations, and your healthcare provider’s guidance. The best form for you depends on your specific health needs.

For Vitamin B2 (as Riboflavin-5-Phosphate), the typical dosing range is not yet documented in our database. Individual dose requirements vary based on health goals, body weight, and existing nutrient intake.

Side Effects: Specific side effect data for these forms is not yet documented in our database. In general, consult your healthcare provider regarding tolerability at higher doses.

These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before starting or changing a supplement regimen.

The following studies and findings inform FormulaForge classifications for Riboflavin:

Riboflavin absorption occurs via a saturable carrier-mediated process in the upper GI tract; a gastroretentive device significantly elevated riboflavin bioavailability by extending residence in the narrow absorption window. PMID: 16806558

A human study characterizing the absorption, metabolism, and excretion of orally administered riboflavin-5'-phosphate (FMN). PMID: 6030496

Riboflavin administered orally as 5'-phosphate flavin mononucleotide behaved as an actively-transported compound with measurable absorption kinetics in controls and quadriplegic patients. PMID: 4004520