Biotin Daily Intake


Was looking into the nutrition facts for a multivitamin that I’m taking and found that it says 75 micrograms of biotin is only 25% of the recommended daily intake. I double checked and saw that this seems to be the case for the general daily recommended intake. The DRI in this page, though, doesn’t show a value higher than 30 micrograms for any age group.

I was wondering what the actual DRI for this was or if there are other factors regarding biotin intake that I haven’t accounted for. Any insight would be appreciated.


… it looks like someone is off by a factor of 10. Misplaced decimal, anyone? It’s pretty damn common.

Ah, footnotes:

“This table (taken from the DRI reports, see presents Recommended Dietary Allowances (RDAs) in bold type and Adequate Intakes (AIs) in ordinary type followed by an asterisk (*). An RDA is the average daily dietary intake level; sufficient to meet the nutrient requirements of nearly all (97-98 percent) healthy individuals in a group. It is calculated from an Estimated Average Requirement (EAR). If sufficient scientific evidence is not available to establish an EAR, and thus calculate an RDA, an AI is usually developed.”

So basically, there is no real firmly established levels for Biotin. 30 ug is just the baseline need for the majority, and there’s no established maximum.

And from NIH:

“There is no recommended dietary allowance (RDA) established for biotin. The adequate intakes (AI) for biotin are 7 mcg for infants 0-12 months, 8 mcg for children 1-3 years, 12 mcg for children 4-8 years, 20 mcg for children 9-13 years, 25 mcg for adolescents 14-18 years, 30 mcg for adults over 18 years and pregnant women, and 35 mcg for breast-feeding women.”

So 30 ug is clearly the correct figure to use.


On the other end of the spectrum, hair & nail supplements will usually dose pretty high on biotin (upwards to 1k%, or around 3000 mcg / .003 grams), and as far as I’ve been able to find, there’s no evidence of biotin toxicity.

If you’re up for it, buying biotin powder in bulk is actually really cheap for how long it lasts. The effect is pretty noticeable after a month of just .0003 grams (I believe I pulled this RDI from Rob’s initial post, and ended up sticking with it). After a number of months, and for someone with already strong finger nails, it feels like I could almost scale walls with these things.

I think in this case many RDI / DRI of biotin reflect the minimum recommended doses, as opposed to the ideal, and as usual, YMMV.