What it does in the body
- Pyruvate carboxylase cofactor (gluconeogenesis — converting pyruvate to oxaloacetate)
- Acetyl-CoA carboxylase cofactor (fatty acid synthesis initiation)
- Propionyl-CoA carboxylase cofactor (odd-chain fatty acid and amino acid catabolism)
- 3-methylcrotonyl-CoA carboxylase cofactor (leucine catabolism)
- Gene regulation via histone biotinylation and chromatin remodeling
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | 30 mcg (AI) | NIH/IOM |
| Adult female | 30 mcg (AI) | NIH/IOM |
| Pregnancy | 30 mcg | WHO/IOM |
| Children | 8-20 mcg (ages 1-13) | WHO |
| Older adults | 30 mcg | NIH |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Beef liver | 40.5 mcg per 100g | global |
| Eggs (cooked whole) | 20.1 mcg per 100g | global |
| Salmon | 5.0 mcg per 100g | global |
| Pork chop | 3.8 mcg per 100g | global |
| Sweet potato | 2.4 mcg per 100g | Americas/Africa |
| Almonds | 4.4 mcg per 100g | Mediterranean/Americas |
| Soybeans (cooked) | 19.3 mcg per 100g | East Asia |
| Banana | 0.12 mcg per 100g | Tropics |
If you don't get enough
Mild: Thinning hair, brittle nails, mild dermatitis
Moderate: Periorificial dermatitis (scaly rash around eyes, nose, mouth), conjunctivitis, depression, lethargy
Severe: Alopecia totalis, severe dermatitis, neurological symptoms (paresthesias, ataxia, seizures), immune dysfunction, metabolic acidosis in inherited biotinidase deficiency
Time to onset: Weeks to months; biotinidase deficiency in neonates presents within the first months of life
Too much
Upper limit: No established UL
No known direct toxicity. MAJOR concern is laboratory test interference: high-dose biotin supplements cause clinically dangerous false results in streptavidin-biotin assays (troponin, TSH, many hormones).
How well you absorb it
Nearly 100% from free biotin in supplements; 40-60% from protein-bound biotin in foods (requires biotinidase to cleave)
Helped by: Biotinidase enzyme (cleaves protein-bound biotin), Normal gut flora (synthesize small amounts of biotin)
Hindered by: Avidin in raw egg whites (binds biotin with extreme affinity; cooking denatures avidin), Prolonged antibiotics (reduce gut bacterial biotin synthesis), Anticonvulsants (phenytoin, carbamazepine, valproate)
Cooking & storage
Biotin is relatively heat-stable. Cooking eggs denatures avidin, making the biotin in eggs available for absorption. Boiling and processing cause minimal biotin losses (10-20%).
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
