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Riboflavin

Riboflavin suppliers and sourcing guide

Riboflavin (vitamin B2) is a yellow to orange-yellow crystalline powder with a slight odor and bitter taste that dissolves poorly in water. Most commercial riboflavin is now made by fermentation with microorganisms such as Bacillus subtilis or the fungus Ashbya gossypii, then purified and crystallized; chemical synthesis is a smaller source. It is used both as a vitamin and as a yellow food color, and brands buy it as fine powder, granulated tableting grade, or as the more water-soluble riboflavin 5'-phosphate.

Also known as
Vitamin B2 · Lactoflavin · E101 · CAS 83-88-5
Facts checked
November 2026

Forms and grades of riboflavin

Suppliers sell different products under the same name. Specify the one you need.

  • USP / FCC crystalline powder

    High-purity riboflavin tested to pharmacopeia or Food Chemicals Codex monographs, for supplements and fortified foods.

  • Granular or direct-compression grade

    Granulated riboflavin that flows and compresses better and dusts less in tablets.

  • Color grade

    Riboflavin offered for yellow coloring, sometimes as dispersions; check whether a riboflavin 5'-phosphate color is meant instead.

  • Feed grade

    Lower-purity fermentation riboflavin for animal nutrition; not for human food or supplements.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Assay
Riboflavin content on a dried basis by HPLC, UV, or the fluorometric method in pharmacopeia monographs.
Identity
UV-visible spectrum or HPLC against a reference standard, plus fluorescence in solution.
Lumiflavin
Limit test for lumiflavin, a light-breakdown product named in pharmacopeia monographs.
Loss on drying and residue on ignition
Moisture and inorganic residue, standard monograph purity tests.
Heavy metals
Lead and other elemental impurities by ICP-MS against the monograph or supplier limit.
Microbiology and GMO documentation
Total aerobic count, yeast and mold and pathogens, plus statements on the production strain for non-GMO claims.

Storage, lots and expiry

Storage and shelf life

Riboflavin is stable to heat and air as a dry powder but breaks down in light, especially in solution, so keep it in closed, light-proof containers in a cool, dry place. Suppliers set shelf life or a retest date, with assay as the usual retest check.

Lots and expiry dates

Record assay per lot and the production route (fermentation or synthesis) if your labels or non-GMO claims depend on it. Keep feed and food grades as separate items and rotate FEFO.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

  • 21 CFR 184.1695 affirms riboflavin as GRAS as a nutrient supplement, used in food with no limitation other than current good manufacturing practice, and says it may be made by chemical synthesis, by the organism Eremothecium ashbyii, or isolated from natural sources.

    Source: ecfr.gov (opens in a new tab)
  • 21 CFR 73.450 lists riboflavin as a color additive for coloring foods generally, exempt from certification.

    Source: ecfr.gov (opens in a new tab)
  • 21 CFR 101.9(c)(8)(iv) sets the Reference Daily Intake for riboflavin at 1.3 mg for adults and children 4 years and older.

    Source: ecfr.gov (opens in a new tab)

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Riboflavin suppliers

Manufacturers and distributors whose own websites say they sell it.

  • Fenchem

    Manufacturer · Nanjing, China

    Nanjing-based maker and marketer of ingredients for food, nutrition, personal care and feed. Its food and nutrition range includes vitamin C and the main B vitamins in several forms.

Suppliers are in alphabetical order and none pays to appear. Each claim is checked against the supplier’s own website on the date shown. Ask for the specification sheet and a recent COA before you order, and confirm details with the supplier.

Frequently asked questions

What forms of riboflavin can brands buy?

Common forms include uSP / FCC crystalline powder, granular or direct-compression grade, color grade and feed grade. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for riboflavin include?

Expect assay, identity, lumiflavin, loss on drying and residue on ignition, heavy metals and microbiology and GMO documentation, each with its method, specification and result for that lot.

How should riboflavin be stored?

Riboflavin is stable to heat and air as a dry powder but breaks down in light, especially in solution, so keep it in closed, light-proof containers in a cool, dry place. Suppliers set shelf life or a retest date, with assay as the usual retest check.

What is the regulatory status of riboflavin?

21 CFR 184.1695 affirms riboflavin as GRAS as a nutrient supplement, used in food with no limitation other than current good manufacturing practice, and says it may be made by chemical synthesis, by the organism Eremothecium ashbyii, or isolated from natural sources. 21 CFR 73.450 lists riboflavin as a color additive for coloring foods generally, exempt from certification. 21 CFR 101.9(c)(8)(iv) sets the Reference Daily Intake for riboflavin at 1.3 mg for adults and children 4 years and older.

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