Biotin AI Table
| Life stage | AI (mcg/day) |
|---|---|
| Infant 0–6 mo | 5 |
| Infant 7–12 mo | 6 |
| 1–3 years | 8 |
| 4–8 years | 12 |
| 9–13 years | 20 |
| 14–18 years | 25 |
| 19+ years | 30 |
| Pregnancy | 30 |
| Lactation | 35 |
| Upper limit | none has been set |
| Food | Portion | mcg | %DV |
|---|---|---|---|
| Beef liver, cooked | 3 oz | 30.8 | 103% |
| Egg, whole | 1 large | 10 | 33% |
| Sunflower seeds, roasted | 1 oz | 9.6 | 32% |
| Canned salmon, in water | 3 oz | 5 | 17% |
| Sweet potato, cooked | 1/2 cup | 4.5 | 15% |
| Pork chop, cooked | 3 oz | 3.9 | 13% |
| Hamburger patty | 3 oz | 3.8 | 13% |
| Almonds, roasted | 1 oz | 1.5 | 6% |
| Tuna, canned | 3 oz | 0.6 | 2% |
Biotin is the supplement aisle's quietest scandal: 'hair, skin and nails' formulas sell doses of 5,000-10,000 mcg against a daily requirement of 30 micrograms - a hundredfold to three-hundredfold markup over what the body needs - and the evidence under the claims is close to empty. The NIH's verdict after reviewing the trials: biotin improves hair and nails only in people whose hair and nail problems were caused by biotin deficiency in the first place, which is a vanishingly small group in any developed country.
The food table is easy to clear and interesting to read: beef liver delivers a full day in one serving (30.8 mcg, 103% DV), one whole egg carries a third, sunflower seeds 32%, and canned salmon, pork, sweet potato and almonds keep the shelf stocked. Gut bacteria synthesize biotin on top of that. True deficiency exists in exactly two populations: people with rare biotinidase enzyme deficiency (caught by newborn screening) and patients on long-term tube feeding or anticonvulsants - plus, classically, anyone eating raw egg whites daily.
That last case is the table's chemistry story: raw egg white is packed with avidin, a protein that binds biotin so tightly the body cannot absorb it - the original 'egg-white injury' experiments in the 1930s are how scientists proved biotin was a vitamin at all. Cooking denatures avidin, which is why nobody gets this from an omelet. The modern hazard is different: the FDA warns that megadose biotin supplements can interfere with hospital lab assays - including troponin, the heart-attack test - as recently as 2022.
How to use
- Find your row: 30 mcg a day for every adult and teen 19+, and every adult life stage including pregnancy (30) and breastfeeding (35); teens 14-18 need 25; children run 8-20 mcg; infants 5-6 mcg.
- Clear it at breakfast, not the beauty aisle: an egg (10 mcg) plus sunflower seeds or almond butter (9.6/1.5) puts an adult near the AI before lunch; a serving of liver, salmon or pork once or twice a week banks the rest - the average mixed diet needs no supplement at all.
- Treat the pill bottle as a lab hazard: if you take biotin at 5,000 mcg+ (hair formulas) and ever have bloodwork drawn, tell the phlebotomist - the FDA has documented biotin interference with troponin, thyroid and hormone assays, misreading results in both directions - and stop high-dose biotin about three days before any lab panel.
Frequently asked questions
How much biotin do I need per day?
The NIH Adequate Intake is 30 mcg a day for all adults 19+, including pregnancy; breastfeeding needs 35. Teens 14-18 need 25; children scale from 8 mcg (ages 4-8) to 20 (9-13); infants 5-6. There is no DV gap to chase - the Daily Value on labels is the same 30 mcg - and no UL, because no toxicity syndrome exists. Deficiency is rare enough that newborn screening programs test for the one inherited cause (biotinidase deficiency).
What foods are highest in biotin?
Beef liver tops the list at 30.8 mcg per 3 ounces (103% DV). The everyday shelf: one whole egg 10 mcg (33%), sunflower seeds 9.6 per ounce (32%), canned salmon 5 per 3 ounces (17%), pork chop and hamburger about 3.8-3.9 (13%), sweet potato 4.5 per half cup (15%), almonds 1.5 per ounce (6%). On top of diet, gut bacteria synthesize biotin. The only food that subtracts is raw egg white - its avidin protein binds biotin and blocks absorption, and cooking disables it.
Does biotin actually help hair and nails?
The honest evidence review says: only if you were deficient to begin with. Improved hair and nail quality is documented in deficiency states - brittle-nail syndrome cases, biotinidase deficiency, some anticonvulsant patients - and trials in people with normal biotin status are essentially absent or null. The NIH conclusion is that claims in healthy people are unsupported. Since the average diet already meets the 30 mcg AI, the 5,000-10,000 mcg beauty doses are treating a deficiency nobody in the room has.
Why does the FDA warn about biotin supplements?
Because megadose biotin scrambles hospital labs: many immunoassays use biotin-streptavidin chemistry, and circulating biotin at 5,000-10,000 mcg levels can interfere with them - the FDA safety communications (2017, updated 2019/2022) document falsely low troponin (missing heart attacks) and skewed thyroid and hormone results. The practical rules: disclose biotin supplements before any bloodwork, and stop high-dose products roughly three days before lab tests so levels wash out.
What is raw egg white injury - should I worry?
Only if raw whites are a daily habit. Egg-white avidin binds biotin with one of the strongest non-covalent bonds in biology, and the 1930s 'egg-white injury' experiments - animals fed raw whites developed dermatitis, hair loss and nerve symptoms, cured by a 'protective factor' named biotin - is how the vitamin was discovered. Cooked egg whites denature the avidin completely; a smoothie with raw whites now and then is trivia, but bodybuilders drinking them daily have induced genuine biotin deficiency.