E101A · Riboflavin-5-phosphate
- WHO
- Safe
- FDA
- Safe
- EFSA
- Safe
- FSANZ
- Safe
- Japan
- Safe
- UK FSA
- Safe
- Health Canada
- Safe
What is E101A?
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.
What the evidence says
- 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.
Frequently asked questions
Is E101A safe?
Our overall verdict for E101A (Riboflavin-5-phosphate) is “Safe”, based on the most cautious of the major regulators’ positions — FDA: safe; WHO: safe; EFSA: safe; FSANZ: safe; Japan: safe; UK FSA: safe; Health Canada: safe.
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.
Watch E101A
Get an email if the EFSA or FDA position on Riboflavin-5-phosphate changes, or when new research is added to this page.
EatMatrix reads any ingredient list with your camera and flags every additive instantly.
This page summarises publicly available regulatory assessments and research. It is general information, not medical advice. Sources: EFSA, FDA, WHO and the studies linked above.