Riboflavin (E 101)

Last reviewed October 19, 2026

In plain words: Riboflavin (E 101) is vitamin B2. In food it is both a nutrient and a yellow color.

What the evidence review says

Riboflavin is vitamin B2, which is also a yellow color. We found no notable concern at current food uses. EFSA did not set an acceptable daily intake because some long-term studies were missing, but concluded authorized color uses were unlikely to be a safety concern. It can turn urine bright yellow, an expected effect of the body passing extra vitamin.

No notable concern at current food uses. Human studies have not reported significant harm from high oral intakes, absorption is limited at high doses, and European reviewers did not set an upper level. EFSA's 2013 color re-evaluation still declined to set an ADI because chronic, reproductive, and developmental studies were missing, but concluded that authorized color uses were unlikely to be a safety concern. It can turn urine bright yellow. That is an expected effect of the vitamin being excreted.

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This page is for general education. It is not medical advice and does not replace advice from your doctor, pediatrician, allergist or registered dietitian. Research changes; we review these pages when new evidence or rules come out. Last reviewed October 19, 2026.