nutrient
Vitamin B7 (biotin)
A water-soluble vitamin that acts as a cofactor for carboxylase enzymes in fat, glucose and amino-acid metabolism.
Biotin is found free and protein-bound in foods. Several carboxylases depend on biotin to add carbon dioxide during metabolic reactions.
What it does
Biotin-dependent carboxylases support fatty-acid synthesis, gluconeogenesis and the breakdown of branched-chain amino acids. Biotin deficiency is rare.
Where it comes from
Eggs, fish, meat, nuts, seeds and some vegetables provide biotin, but food databases can differ in whether they capture free and protein-bound forms.
Food sources
Per 100 g| Food | Per 100 g | Daily reference |
|---|---|---|
| Almonds | 57 µg | 142.5% |
| Ground flaxseed | 33.8 µg | 84.5% |
| Rolled oats | 21.9 µg | 54.75% |
| English walnuts, raw | 17.3 µg | 43.25% |
| Chia seeds, dry | 14.5 µg | 36.25% |
Show 8 more foods
| Food | Per 100 g | Daily reference |
|---|---|---|
| Brown rice, long-grain, raw | 4.99 µg | 12.48% |
| Soy milk, unsweetened and shelf-stable | 3.34 µg | 8.35% |
| Mature carrots, raw | 2.22 µg | 5.55% |
| Spinach | 1.66 µg | 4.15% |
| Oat milk, unsweetened and refrigerated | 1.41 µg | 3.52% |
| Orange bell pepper, raw | 0.58 µg | 1.45% |
| Blueberries, raw | 0.3 µg | 0.75% |
| Strawberries, raw | 0.19 µg | 0.48% |
Compared with EFSA’s adult reference of 40 µg/day.
About these amounts
These values describe the named food and preparation. A 100 g comparison is not a suggested serving. Small amounts are rounded for display; an unreported amount is not zero.
Healthy European adults. Adequate intake: 40 µg/day. These are population references, not individual targets.
The source records and EFSA guidance are linked in References below.
Related topics
Vitamin B7 (biotin) supports metabolism of Glucose
Biotin-dependent enzymes participate in gluconeogenesis and other glucose pathways.
Worth knowing
Lab-test interference matters. High-dose biotin supplements can interfere with some laboratory tests, producing misleading results.
Hair claims have limited support. Biotin supplements are often marketed for hair and nails, but evidence of benefit in otherwise healthy people is limited to small studies and case reports.
A closer look
Why cooking changes egg white
Raw egg white contains avidin, a protein that binds biotin and prevents its absorption. Cooking changes avidin’s structure so it no longer blocks absorption this way.
References
Source-checked local draft.
Human editorial review pending.
- NIH Office of Dietary SupplementsBiotin: Fact Sheet for Health ProfessionalsChecked 2026-09-05
- European Food Safety AuthorityDietary Reference Values for nutrients: Summary reportChecked 2026-09-05
- U.S. Department of Agriculture, Agricultural Research ServiceFoodData Central Foundation Foods, April 2026 JSON releaseChecked 2026-09-05
- European Food Safety AuthorityScientific Opinion on Dietary Reference Values for magnesiumChecked 2026-09-04
- NIH Office of Dietary SupplementsMagnesium: Fact Sheet for Health ProfessionalsChecked 2026-09-04
- USDA Agricultural Research ServiceFoodData CentralChecked 2026-09-04