E101a / Colours
Riboflavin-5-phosphate
Safety in brief
Safe
Recorded EatMatrix rating, not a new clinical review. The amount, your sensitivities and country rules still matter.
- Watch for
- No allergen or sensitivity is recorded for this ingredient here. Check the whole product label; this is not an allergen-free guarantee.
- Our advice
- Read the whole food label and consider how often you eat the product. A name or E number does not tell you the amount, and an ingredient rating cannot assess the entire food.
What it is
Riboflavin-5'-phosphate is the phosphorylated, biologically active form of Vitamin B2, used as both a yellow-orange food colorant and a nutrient additive. It functions in the body as a coenzyme supporting energy metabolism, healthy skin, eyes, and nerve function. It is considered a safe food additive by EFSA and the FDA at typical use levels.
Also appears on labels as: E101a, E 101a, E-101a, Riboflavin-5-phosphate, Riboflavin 5′-phosphate, Riboflavin 5-phosphate, Flavin mononucleotide, FMN, Vitamin B2 phosphate, Phosphorylated riboflavin, Riboflavin phosphate, E101a colouring.
Dietary information
- Vegan
- Yes
- Halal
- Yes
- Gluten-free
- Yes
- Allergens
- None recorded
Recorded ingredient information. Check the product label or certification: sources, other ingredients and cross-contact can vary.
Research & body effects
Health notes from our ingredient record
- Generally recognized as safe at typical food levels; it is a required vitamin, not a synthetic risk additive.
- May cause harmless bright yellow discoloration of urine at higher intakes.
Country rules
Country checks for E101A
Permission depends on the market, type of food, amount and conditions. A scientific opinion or an E-number alone does not establish a legal use. These checks are separate from the stored EatMatrix rating.
Compare all eight markets and their sources
| Market | What is checked |
|---|---|
| European Union | No exact code match in the Annex II Part B list (version 2026-08-18, read 2026-10-07). Identity, subform and legal-use review are pending. This does not establish a permission or a ban. |
| Great Britain | No verified exact register record in this review. Identity and current use rules need checking; missing a record does not establish a ban. |
| United States | Complete current-use review pending. Any scoped provision in the label guide above applies only to the stated use. FDA explains the applicable food-additive and GRAS framework. |
| Northern Ireland | Review pending. Check the applicable EU rules and territory arrangements; the GB register alone does not establish this status. FSA guidance is a starting source, not a verified permission for this entry. |
| Canada | Exact preparation needs confirmation The Canadian food-colour list names riboflavin, not a separate riboflavin-5-phosphate entry. A vitamin use also has a different regulatory scope from a technological colour use. EatMatrix reading: Match the phosphate form, counter-ion, specifications and intended vitamin or colour use. Do not inherit the riboflavin colour rows. Name and category review: . This describes the legal source check, not a finding that the ingredient is safe, unsafe or untested. Sources and names checkedNames checked: Riboflavin-5-phosphate; Riboflavin 5-phosphate; Riboflavin Sodium Phosphate. All 15 Health Canada permitted-additive lists were checked by exact name, with the reviewed alternatives above. E-numbers alone are not Canadian ingredient names. The Justice Canada consolidation read was current to 21 September 2026. A complete product decision also requires its composition, specifications, intended food and use, quantities, applicable separate provisions and any later changes. |
| Australia | Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry. |
| New Zealand | Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry. |
| Japan | Review pending. The relevant list, identity and use standards need an additive-specific check. CAA food-additive lists is a starting source, not a verified permission for this entry. |
Sources & review status
Check what each source covers: an authority’s conclusion, a research finding and a country’s legal permission answer different questions.
What this guide covers
- Original ingredient record
- No research links in the original record. Sources added separately to this guide are not included in this count.
This guide brings together our ingredient record and the dated sources shown here. Missing information describes a gap in this guide; it does not mean an ingredient is untested, safe or harmful. This is not a complete review of every study, preparation or current country rule. The amount in a product and how it is used still matter.
How to read the ratings, research and country checksAgency labels recorded by EatMatrix
These are imported database classifications, not verified current statements from each authority. Use the dated official sources below for their actual scope and conclusions.
| Authority | Database label |
|---|---|
| FDA | Safe |
| WHO | Safe |
| EFSA | Safe |
| FSANZ | Safe |
| Japan | Safe |
| UK FSA | Safe |
| Health Canada | Safe |
Database updated: . What does an E number mean on a food label?
Common questions
Frequently asked questions
What is EatMatrix's recorded rating for E101A?
The recorded EatMatrix rating for E101A (Riboflavin-5-phosphate) is “Safe”. It is calculated from labels stored in our ingredient database. These labels are not verified current regulator decisions or country permissions. A database update date is not a scientific review date.
Is E101A vegan, halal or gluten-free?
According to our ingredient data for Riboflavin-5-phosphate — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E101A and why is it used?
Riboflavin-5'-phosphate is the phosphorylated, biologically active form of Vitamin B2, used as both a yellow-orange food colorant and a nutrient additive. It functions in the body as a coenzyme supporting energy metabolism, healthy skin, eyes, and nerve function. It is considered a safe food additive by EFSA and the FDA at typical use levels.
Does E101A contain allergens?
No known allergens are recorded for Riboflavin-5-phosphate.
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This page shows information and classifications recorded in our ingredient database. Current scientific and market-specific verification remains pending as described above. It is general information, not medical advice.