Riboflavin
83-88-5 · (-)-riboflavin · 2vxa · 6,7-Dimethyl-9-D-ribitylisoalloxazine · 7,8-Dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)isoalloxazine · 7,8-Dimethyl-10-ribitylisoalloxazine · Aqua-Flave · Beflavin · Beflavine · Bisulase · C.I. Food Yellow 15 · Dermadram · E 101(i) · E-101(iii) · Fiboflavin · Flavaxin · Flavin BB · Flaxain · Freeda · HYRE · INS NO. 101(I) · Ins no.101(iii) · Ins-101(iii) · Isoalloxazine, 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)- · Isoalloxazine, 7,8-dimethyl-10-D-ribityl- · Lacto-flavin · Lactobene · Lactoflavin · Lactoflavine · PureVita Vitamin B2 · Ribipca · Ribocrisina · Riboderm · Riboflavin · Riboflavin (Vitamin B2) · Riboflavina · Riboflavine · Riboflavinequinone · Riboflavinum · Ribosyn · Ribotone · Ribovel · Russupteridine Yellow III · Vitaflavine · Vitamin B 2 · Vitamin B-2 · Vitamin B2 · Vitamin b2 (as riboflavin) · Vitamin Bi · Vitamin G · vitamin-b2 · vitaminum b2 · Vitasan B2 · E101 · 1-Deoxy-1-(3,4-dihydro-7,8-dimethyl-2,4-dioxobenzo[g]pteridin-10(2H)-yl)-D-ribitol · 7,8-dimethyl-10-((2R,3R,4S)-2,3,4,5-tetrahydroxypentyl)benzo(g)pteridine-2,4-dione · 7,8-dimethyl-10-((2S,3S,4R)-2,3,4,5-tetrahydroxypentyl)benzo[g]pteridine-2,4(3H,10H)-dione · 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)benzo(g)pteridine-2,4(3H,10H)-dione · 7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]-2H,3H,4H,10H-benzo[g]pteridine-2,4-dione · 7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo[g]pteridine-2,4-dione · Benzo(g)pteridine-2,4(3H,10H)-dione, 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)- · Riboflavin · Riboflavins · i) riboflavin ii) riboflavin-5′-fosfát · Riboflaviinid · Riboflaviinit · Riboflavin · Riboflavina · Riboflavinai · Riboflavinas · Riboflavine · Riboflavinen · Riboflaviner · Riboflavines · Riboflavini · Riboflavins · Riboflavíny · Ryboflawiny · Ριβοφλαβίνες · РибофлавиниE number E101CAS 83-88-5
Listed as a colour by Canada, the EU and the US.
Listed as colours (CA, EU, US) · flavour enhancers (US) · nutrient supplements (US) · flavouring agents and adjuvants (US)
- Canada: Food colour — Health Canada, List of Permitted Food Colours (List 3)
- European Union: Colours — Regulation (EC) No 1333/2008, Annex II, Part B, 1. Colours (consolidated text 02008R1333-20260818)
- United States: Color additive (21 CFR part 73) — 21 CFR 73.450
- United States: Color or coloring adjunct — FDA, Substances Added to Food: RIBOFLAVIN
- United States: Flavor enhancer — FDA, Substances Added to Food: RIBOFLAVIN
- United States: Nutrient supplement — FDA, Substances Added to Food: RIBOFLAVIN
- United States: Nutrient supplements — 21 CFR 184.1695, citing 21 CFR 170.3(o)(20)
- United States: Flavoring agent or adjuvant — FDA, Substances Added to Food: RIBOFLAVIN
Riboflavin is vitamin B2, a yellow-orange compound used both as a nutrient and as a colour. It appears in dairy products, desserts, cereals and drinks, and is what makes some vitamin preparations bright yellow.
Where it is and isn’t permitted
| Jurisdiction | Status | Scope and limits | Citation |
|---|---|---|---|
| Australia and New Zealand | Permitted, with conditions | 47 food categories no numerical limit (good manufacturing practice) Show every food category
| Food Standards Code, Schedule 15, S15—5and 46 further provisionsretrieved 2026-10-17 |
| Canada | Permitted | no numerical limit (good manufacturing practice) 4 permitted uses Show every permitted use
| Health Canada, List of Permitted Food Colours (List 3)and 3 further provisionsretrieved 2026-10-17 |
| European Union | Permitted, with conditions | 47 food categories highest permitted level 100 mg/l Show every food category
| Regulation (EC) No 1333/2008, Annex IIand 46 further provisionsretrieved 2026-10-18 |
| Great Britain | Permitted, with conditions | 54 food categories highest permitted level 100 mg/kg or mg/l Show every food category
| Assimilated Regulation (EC) No 1333/2008, Annex II (as at 28 June 2024)and 53 further provisionsretrieved 2026-10-18 |
| Japan | Permitted, with conditions | Designated additive: Appended Table 1, item 446, リボフラビン（別名ビタミンＢ２） (“Riboflavin (Vitamin B2)” in the unofficial English translation). …Designated additive: Appended Table 1, item 446, リボフラビン（別名ビタミンＢ２） (“Riboflavin (Vitamin B2)” in the unofficial English translation). Standards for use — Specifications and Standards for Foods, Food Additives, etc. (MHW Notification No. 370 of 1959), Part II (Food Additives), F (Standards for use): The Notification sets no standard for use (使用基準) for this additive, so it is not restricted there to particular foods or amounts. Compositional specifications for this additive, in the same Notification, are not imported and are not shown here; nor are the general rules in F 添加物一般, which apply to every additive. | Regulations for Enforcement of the Food Sanitation Act (MHW Ordinance No. 23 of 1948), Appended Table 1retrieved 2026-10-18 |
| South Korea | Permitted, with conditions | Designated food additive: Standards and Specifications for Food Additives, Part III, 1. …Designated food additive: Standards and Specifications for Food Additives, Part III, 1. 일반식품첨가물 (general food additives), 비타민B2 (“Riboflavin”, the English the Code prints beside it); the Code marks it as also usable as a nutrient fortifier; 3. 영양강화제 (nutrient fortifiers), 비타민B2; nutrient: 비타민B2; the Code marks it as also usable as a general food additive. Main use (주용도) of 비타민B2: 착색료. Standard for use (사용기준) of 비타민B2: (1) [to be used under the general standard for use in II. 2. 1), the minimum amount that achieves the technical effect, with no limit set for this additive in particular] “II. 2. 1)의 규정에 따라 사용하여야 한다.” The Korean is the standard as published. There is no official English translation of the current Code (the English version on MFDS’s website is the 2020 edition and has no legal effect); the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications (Part IV) are not imported, nor are the general standards in Part II, which apply to every additive. | Standards and Specifications for Food Additives (식품첨가물의 기준 및 규격), MFDS Notification, Part III (Standards for use, by item)retrieved 2026-10-18 |
| United States | Permitted | 21 CFR 73.450and 1 further provisionretrieved 2026-10-17 | |
| Codex Alimentarius | Not listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited. |
How much is permitted
A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.
| Australia and New Zealand | — | 47 GMP |
|---|---|---|
| Canada | — | 4 GMP |
| European Union | 100 mg/kg | 2 numeric limit, 45 quantum satis |
| Great Britain | 100 mg/kg | 2 numeric limit, 4 several limits, 48 quantum satis |
| Japan | — | 1 no quantity stated |
| South Korea | — | 1 no quantity stated |
| United States | — | 2 no quantity stated |
What it is made from
Produced commercially by fermentation with bacteria or fungi, and formerly by chemical synthesis. It also occurs naturally in milk, eggs and liver, but the additive is not extracted from those.
- Vegan
- Vegetarian
Compare other additives on the dietary indexes.
- CAS registry number
- 83-88-5
- InChIKey
- AUNGANRZJHBGPY-SCRDCRAPSA-N
- PubChem
- CID 493570
How JECFA defines it
The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.
INS 101(i) Riboflavin
Synonyms: Vitamin B 2, lactoflavin; INS No. 101(i) Lactoflavin; Vitamin B2
Assay, identification and purity criteria
Description and assay
- Specification history
- Prepared at the 31st JECFA (1987), published in FNP 38 (1988) and in FNP 52 (1992). Metals and arsenic specifications revised at the 59th JECFA (2002). A group ADI of 0-0.5 mg/kg bw for riboflavin from Bacillus subtilis, synthetic riboflavin and riboflavin-5-phosphate was established at the 51st JECFA (1998).
- Chemical names
- Riboflavin; 3,10-dihydro-7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo-[g]pteridine-2,4-dione; 7,8-dimethyl-10-(1'-D-ribityl)isoalloxazine,
- C.A.S. number
- 83-88-5
- Chemical formula
- C 17 H 20 N 4 O 6
- Formula weight
- 376.37
- Assay
- Not less than 98%
- DESCRIPTION
- Yellow to orange-yellow crystalline powder, with slight odour
- FUNCTIONAL USES
- Colour
- METHOD OF ASSAY
- Carry out the assay in subdued light. In a brown glass 500 ml volumetric flask, suspend 65.0 mg of the sample in 5 ml of water, ensuring that it is completely wetted, and dissolve in 5 ml of 2 N sodium hydroxide solution. As soon as dissolution is complete, add 100 ml of water and 2.5 ml of glacial acetic acid and dilute to 500.0 ml with water. Place 20.0 ml of this solution in a brown glass 200 ml volumetric flask, add 3.5 ml of a 1.4% w/v solution of sodium acetate and dilute to 200.0 ml with water. Measure the absorbance (A) at the maximum at 444 nm. % Riboflavin = (A×5000)/(328 × W) where A = absorbance of the sample solution at 444 nm W = weight of sample in g
Identification
- Solubility (Vol. 4)
- Very slightly soluble in water; practically insoluble in alcohol, chloroform, acetone and ether; very soluble in dilute alkali solutions
- Spectrophotometry (Vol. 4)
- Using the aqueous solution from the Assay, determine the absorbance (A) at 267 nm, 375 nm and 444 nm. The ratio A 375 /A 267 is between 0.31 and 0.33. The ratio A 444 /A 267 is between 0.36 and 0.39.
- Specific rotation
- [alpha] 20, D: Between -115 o and -140 o Dry the sample at 100 o for 4 h. Dissolve 50.0 mg in 0.05 N sodium hydroxide free from carbonate and dilute to 10.0 ml with the same solvent. Measure the optical rotation within 30 min of dissolution.
- Colour reaction
- Dissolve about 1 mg of sample in 100 ml of water. The solution has a pale greenish-yellow colour by transmitted light, and by reflected light has an intense yellowish-green fluorescence which disappears on the addition of mineral acids and alkalis.
Purity criteria
- Loss on drying (Vol. 4)
- Not more than 1.5% (105 o , 4 h)
- Sulfated ash (Vol. 4)
- Not more than 0.1% Test 2 g of the sample (Method I)
- Subsidiary colouring matters
- Prepare the standard for this test for the absence of lumiflavin by diluting 3 ml of 0.1 N potassium dichromate with water to 1000 ml. Pour some chloroform through an alumina column to remove any ethanol. To 10 ml of this chloroform add 35 mg of the sample, shake for 5 min and filter. The colour of the filtrate should be no more intense than that of 10 ml of the standard when viewed in identical containers.
- Primary aromatic amines (Vol. 4)
- Not more than 100 mg/kg calculated as aniline
- Lead (Vol. 4)
- Not more than 2 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”
INS 101(iii) Riboflavin from Bacillus subtilis
Synonyms: Vitamin B2; lactoflavin; INS No. 101(iii)
Assay, identification and purity criteria
Description and assay
- Specification history
- Prepared at the 53rd JECFA (1999) and published in FNP 52 Add 7 (1999), superseding specifications prepared at the 51st JECFA (1998), published in FNP 52 Add 6. Group ADI 0-0.5 mg/kg bw for riboflavin from Bacillus subtilis, synthetic riboflavin and riboflavin-5-phosphate established at the 51st JECFA in 1998.
- SOURCE
- Prepared by submerged fermentation by Bacillus subtilis genetically modified for riboflavin overproduction. The strain is non-pathogenic and non-toxicogenic.
- Chemical names
- Riboflavin; 3,10-dihydro-7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo-[g]pteridine-2,4-dione; 7,8-dimethyl-10-(1'-D-ribityl)isoalloxazine
- C.A.S. number
- 83-88-5
- Chemical formula
- C17H20N4O6
- Formula weight
- 376.37
- Assay
- Not less than 98.0% and not more than 101.0%, calculated on the dried basis
- DESCRIPTION
- Yellow to orange-yellow crystalline powder
- FUNCTIONAL USES
- Colour, nutrient supplement
- METHOD OF ASSAY
- Carry out the assay in subdued light. In a brown-glass 500-ml volumetric flask, suspend 65.0 mg of the sample in 5 ml of water, ensuring that it is completely wetted, and dissolve in 5 ml of 2 N sodium hydroxide solution. As soon as dissolution is complete, add 100 ml of water and 2.5 ml of glacial acetic acid and dilute to 500.0 ml with water. Place 20.0 ml of this solution in a brown glass 200-ml volumetric flask, add 3.5 ml of a 1.4% w/v solution of sodium acetate and dilute to 200.0 ml with water. Measure the absorbance (A) at the maximum, 444 nm. % Riboflavin= (A×5000)/(328×W) where A = absorbance of the sample solution at 444 nm W = weight of sample in g
Identification
- Solubility (Vol. 4)
- Practically insoluble in ethanol, acetone and diethyl ether; very soluble in dilute alkali solutions
- Spectrophotometry (Vol. 4)
- Using the aqueous solution from the Assay, determine the absorbance (A) at 267 nm, 375 nm and 444 nm. The ratio A375/A267 is between 0.31 and 0.33. The ratio A444/A267 is between 0.36 and 0.39.
- Specific rotation
- [alpha] 20 o D: Between -120 and -135 Dry the sample at 100 o for 4 h. Dissolve 50.0 mg in 0.05 N sodium hydroxide free from carbonate and dilute to 10.0 ml with the same solvent. Measure the optical rotation within 30 min of dissolution.
- Colour reaction
- Dissolve about 1 mg of sample in 100 ml of water. The solution has a pale greenish-yellow colour by transmitted light, and by reflected light has an intense yellowish-green fluorescence, which disappears on the addition of mineral acids and alkalis.
Purity criteria
- Loss on drying (Vol. 4)
- Not more than 2.0% (105 o , 4 h)
- Sulfated ash (Vol. 4)
- Not more than 0.1% Test 2 g of the sample (Method I)
- Lumiflavin (Vol. 4)
- Not more than 0.025% See description under TESTS
- Primary aromatic amines (Vol. 4)
- Not more than 100 mg/kg calculated as aniline
- Lead (Vol. 4)
- Not more than 1 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”
- Test: Lumiflavin (Vol. 4)
- Reference Solution: Dissolve 25 mg of lumiflavin in 50.0 ml of chloroform. Dilute 1.0 ml of this solution with chloroform to 20.0 ml, and dilute 2.5 ml of the resultant solution to 100 ml. This solution contains 0.625 μg lumiflavin per ml. Test Solution: Shake 25 mg of the sample with 10.0 ml chloroform for 5 min and filter. Thin Layer Chromatography: Stationary phase: Precoated HPTLC plates of silica gel WRF254, 10 x 20 cm, layer thickness 0.1 mm (Merck Cat No 1.12363) Mobile phase: Water Run length: approx. 6 cm Elution time: approx. 20 min Application volumes: 10 μl of Reference Solution and 10 μl of Test Solution Detection: Dry the plate in a current of cold air and evaluate the fluorescence at 366 nm Any spot in the chromatogram of the Test Solution, which corresponds to the main spot of the Reference Solution, shall not be larger or more intensely coloured than the Reference Solution spot.
Every name it appears under
80 recorded names. A label may use any of them.
E number
- E101
CAS registry number
- 83-88-5
As it appears in regulation
- Riboflavin
- Riboflavins
Other names
- (-)-riboflavin
- 2vxa
- 6,7-Dimethyl-9-D-ribitylisoalloxazine
- 7,8-Dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)isoalloxazine
- 7,8-Dimethyl-10-ribitylisoalloxazine
- Aqua-Flave
- Beflavin
- Beflavine
- Bisulase
- C.I. Food Yellow 15
- Dermadram
- E 101(i)
- E-101(iii)
- Fiboflavin
- Flavaxin
- Flavin BB
- Flaxain
- Freeda
- HYRE
- INS NO. 101(I)
- Ins no.101(iii)
- Ins-101(iii)
- Isoalloxazine, 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)-
- Isoalloxazine, 7,8-dimethyl-10-D-ribityl-
- Lacto-flavin
- Lactobene
- Lactoflavin
- Lactoflavine
- PureVita Vitamin B2
- Ribipca
- Ribocrisina
- Riboderm
- Riboflavin
- Riboflavin (Vitamin B2)
- Riboflavina
- Riboflavine
- Riboflavinequinone
- Riboflavinum
- Ribosyn
- Ribotone
- Ribovel
- Russupteridine Yellow III
- Vitaflavine
- Vitamin B 2
- Vitamin B-2
- Vitamin B2
- Vitamin b2 (as riboflavin)
- Vitamin Bi
- Vitamin G
- vitamin-b2
- vitaminum b2
- Vitasan B2
Systematic names
- 1-Deoxy-1-(3,4-dihydro-7,8-dimethyl-2,4-dioxobenzo[g]pteridin-10(2H)-yl)-D-ribitol
- 7,8-dimethyl-10-((2R,3R,4S)-2,3,4,5-tetrahydroxypentyl)benzo(g)pteridine-2,4-dione
- 7,8-dimethyl-10-((2S,3S,4R)-2,3,4,5-tetrahydroxypentyl)benzo[g]pteridine-2,4(3H,10H)-dione
- 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)benzo(g)pteridine-2,4(3H,10H)-dione
- 7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]-2H,3H,4H,10H-benzo[g]pteridine-2,4-dione
- 7,8-dimethyl-10-[(2S,3S,4R)-2,3,4,5-tetrahydroxypentyl]benzo[g]pteridine-2,4-dione
- Benzo(g)pteridine-2,4(3H,10H)-dione, 7,8-dimethyl-10-(D-ribo-2,3,4,5-tetrahydroxypentyl)-
The EU re-evaluation programme
Every additive authorised in the EU before 20 January 2009 was put back through EFSA by Commission Regulation (EU) No 257/2010, and this one is named in it. What the Regulation required is below; whether the opinion has since been published is not something this site records.
- To be evaluated by 31 December 2015. Named in Annex II, Part I, point 3 as “(i) Riboflavin (ii) Riboflavin-5’-phosphate”, among the additives given priority within its class.
Hazard reference values
EFSA and JECFA have both assessed Riboflavin and their conclusions are not two comparable figures — EFSA records 0.5 mg/kg bw/day, JECFA not specified. An acceptable daily intake is a reference value set by a committee, not a threshold above which harm begins. “Not specified”, “not limited” and “not allocated” are conclusions, not missing data, and they are shown in the words each body used rather than reduced to a number. See where the two committees differ.
Evidence and how bodies read it
What assessing bodies concluded
Each conclusion is paraphrased in the body's own framing, from the published opinion linked beneath it. Where bodies differ, both stand; this site does not adjudicate between them or add a view of its own.
EFSA 2013
The ANS Panel considered it inappropriate to allocate an ADI for riboflavin (E 101(i)) and riboflavin-5'-phosphate sodium (E 101(ii)) because chronic and relevant reproductive toxicity studies were absent. Despite these uncertainties, it concluded that they are unlikely to be of safety concern at the currently authorised uses and use levels.
Common questions
Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.
- What is E 101?
- E 101 is Riboflavin. Riboflavin is vitamin B2, a yellow-orange compound used both as a nutrient and as a colour. It appears in dairy products, desserts, cereals and drinks, and is what makes some vitamin preparations bright yellow.
- What is Riboflavin used for in food?
- It is listed as a colour — the role Canada, the EU and the US assign it. This page shows every function each regulator records, with the citation for each.
- Where is Riboflavin permitted?
- Of the seven regulators this site reads, Australia and New Zealand, Canada, the EU, Great Britain, Japan, South Korea and the US permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
- Is Riboflavin vegan?
- Yes. Riboflavin is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.
Sources for this page
- anz retrieved 2026-10-17
- ca retrieved 2026-10-17
- eu retrieved 2026-10-18
- gb retrieved 2026-10-18
- jp retrieved 2026-10-18
- kr retrieved 2026-10-18
- ecfr retrieved 2026-10-17
- jecfaspecs retrieved 2026-09-23
Full licence terms and publisher details on Sources. How this page is built and updated: Method.
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