Most people living in developed countries with access to unprocessed foods get enough biotin through diet alone and frank deficiency is rare2. That being said, it's important to know the facts including recommended daily dose, overconsumption risk, signs of inadequate intake and deficiency, and where to find the water-soluble micronutrient.
Here, we answer those questions.
What is biotin?
If you're asking about how much biotin you should take daily, it's a safe assumption you have a general idea of what it is. But it never hurts to go over it.
Biotin is an essential B vitamin (translation: we can't adequately produce it, so we must consume it daily) that has several critical roles in the body. "As an essential cofactor3 in the body and a B vitamin able to impact gene expression, biotin has multiple essential and fascinating functions in the body, from the metabolism of carbs, proteins, and fats, to cell signaling," explains mbg's vice president of scientific affairs Ashley Jordan Ferira, Ph.D., RDN.
Speaking of metabolism, one of vitamin B7's most notable physiological roles has to do with cellular energy production: Biotin is a required coenzyme for carboxylases4, or special enzymes that help enable carboxylation reactions in the body involving a variety of organic compounds, including the metabolism of key macronutrients.* For example, carboxylases are involved in the process of insulin release and gluconeogenesis, or the synthesis of glucose from non-carbohydrate sources.
Beauty is another aspect of health that biotin directly supports. "Your hair, skin, and nails are biotin-famous because when biotin deficiency occurs, science demonstrates that the beauty triad suffers (i.e., hair loss, skin issues, and brittle nails)," Ferira shares.
Indeed, biotin is probably most famous for its use in beauty supplements. "Consumers expect biotin to support hair, skin, and nails5 (aka the beauty trifecta), and their enthusiasm is warranted at the mechanistic level, but the clinical research needs to catch up with this overwhelmingly positive public opinion and broad use," Ferira says, noting that she hopes that well-designed clinical trials will be conducted to continue to expand our understanding in these areas of health.
As a friendly reminder, your body cannot make sufficient levels of biotin6 on its own. And while certain bacteria in your gut6 can produce the B vitamin to a certain (highly variable) extent, they also need biotin to grow and survive7. Thus we look to high-quality outside sources for our fill.
What is the recommended amount of biotin per day?
Summarizing the biotin recommended daily intake3 levels per the National Academies, Ferira shares that "baseline biotin daily needs for adults are 30 to 35 micrograms." And interestingly, "these basal needs don't appear to vary by gender or age."
Dietitian and health coach Jessica Cording, M.S., R.D., CDN, breaks these daily needs down further, explaining that adults over 18 need at least 30 micrograms (0.03 milligrams) of biotin each day. Due to its role in embryonic development, the recommended intake increases for pregnant or lactating people, in which case 35 micrograms of the B vitamin are needed daily.
Regular alcohol overuse can cause a lack of this nutrient's absorption, Cording says, in which case biotin deficiency may be of concern. Ferira adds that vegetarians and vegans should also be biotin-conscious since the best food sources of the vitamin are sourced from animals (e.g., eggs, fish, meat, etc.).
Can you take too much biotin?
While overconsumption of some vitamins and minerals is proven to have negative effects in a quantifiable way, that's not the case with biotin. "There is currently no established upper limit for biotin intake, due to a lack of reports of adverse events with high intake," Cording explains.
More specifically, "no adverse effects have been observed at very high levels or oral intake, up to 200 milligrams daily (that's 20,000 micrograms), so there's no compelling data supporting a direct toxicity effect," adds Ferira.
A common misconception is that biotin supplements, or an increased intake of biotin in general, could lead to breakouts.
This, however, has not held up when studied. As board-certified dermatologist Hadley King, M.D., tells mbg, it has been theorized that biotin supplements could contribute to skin blemishes by interfering with the absorption of pantothenic acid (vitamin B5). "However, no studies have shown that taking biotin supplements or having a pantothenic acid deficiency cause [breakouts]," King says.
A case of too much of a good thing, "biotin megadosing can prove challenging for the accurate assessment of key labs, including vitamin D levels as measured by serum 25-hydroxyvitamin D, troponin for cardiac function, HCG for pregnancy testing, thyroid panel results, and others." For this reason, "more is not more in the base of biotin, at least not at these extreme, high levels like 5 milligrams (5,000 micrograms) and up," Ferira concludes.
Again, please consult with your health care practitioner for your own unique needs. As Ferira expounds, "there are certainly specific clinical scenarios under the care of a doctor where intentional, high-dose biotin regimens are utilized, but that's not what we're talking about here for the average individual."
Signs that you need more biotin.
As we said earlier, plain biotin deficiency is rare in the United States. However, it does still exist. As Ferira alluded to before, some of the most obvious clues of vitamin B7 insufficiency involve your hair, skin, and nails.
So there are definitely some key signs that you may not be consuming enough biotin. As Cording shares, these include:
- Skin irritation
- Brittle nails
- Increased hair shedding
It's important to note that these signs can be indicative of many different factors, or etiologies, across the health space, so it's important to check in with your health care provider to be sure.
Good sources of biotin.
If you're looking to up your daily dose, there are certain foods that are especially rich in biotin.
Many of the top dietary sources are from animals. Think organ meats, beef, pork, poultry, fish, and eggs, Ferira explains.
"That's not to say you can't sprinkle biotin into your diet through plant sources, but carnivorous sources are simply some of the most concentrated in this essential B vitamin," Ferira says.
Some of the more common biotin-rich plant sources include bananas, cauliflower, oats, and mushrooms.
In cases where biotin needs cannot be met from food sources due to individual dietary sensitivities or restrictions, biotin supplementation is not only an easy solution but a smart one.
Other people may choose to leverage a daily or semi-regular biotin-containing supplement or blend to ensure daily intake and to promote functional, targeted health benefits.* For example, you can find biotin in hair, skin, and nail vitamins, like mbg beauty & gut collagen+.
This collagen-peptide-led blend contains 500 micrograms of biotin, along with a plethora of other hair, skin, and nail-loving vitamins, botanicals, and bioactives.* This way, you can be sure you're getting enough biotin daily while also enjoying the benefits of a premium beauty-minded supplement.*
Biotin is an essential vitamin with diverse, critical roles in the body. While frank biotin deficiency is rare in developed countries, biotin sufficiency still requires intentional nutrition choices, plus knowing how much you should ingest daily and where to find it.
Adults need to consume a minimum of 30 micrograms of biotin each day (that baseline level increases to 35 micrograms if you are pregnant or lactating). There is not currently an established upper limit for biotin; however, intentionally overconsuming the B vitamin may interfere with certain lab tests.
If you're experiencing increased hair shedding, brittle nails, or skin redness and irritation, you may want to visit a health care provider as those may be signs that you could benefit from more biotin. If you want to learn more about biotin-rich foods, check out this story.
Hannah Frye is the Assistant Beauty Editor at mindbodygreen. She has a B.S. in journalism and a minor in women’s, gender, and queer studies from California Polytechnic State University, San Luis Obispo. Hannah has written across lifestyle sections including health, wellness, sustainability, personal development, and more. She previously interned for Almost 30, a top-rated health and wellness podcast. In her current role, Hannah reports on the latest beauty trends, holistic skincare approaches, must-have makeup products, and inclusivity in the beauty industry. She currently lives in New York City.