E101 · INS 101Sometimes animal

Riboflavin (vitamin B2)

Common US / international name: riboflavin / vitamin B2

Origin: Yellow color and vitamin fortification.
What it depends on: Today mostly fermentation. Older processes used dairy by-products; some specialty grades may still involve animal materials.
Where it typically appears: Fortified cereals, drinks, cheese color, supplements.
Product groups: Dairy, Drinks, Other
Source: EU Reg. No 1333/2008 Annex II; Codex CAC/GL 36-1989; Open Food Facts additives taxonomy (ODbL). As of September 1, 2026