- What is Biotin?
- Bound and Unbound Biotin
- Popular Biotin Sources
- What Is Biotin Used For?
- What Are the Recommended Doses of Biotin?
- When To Take More Biotin?
- Biotin for Skin, Hair and Nails
- Are There Any Biotin Side Effects?
- Biotin Interactions
What is Biotin?
Biotin, also known as vitamin H, coenzyme R, and vitamin B7, is a water-soluble B vitamin, meaning that it dissolves in the body after being ingested. It is needed for cellular metabolism and it is to various degrees present in all living cells.
Basically, everything that is alive uses biotin. This includes humans, animals, plants, and single-cell organisms.
The origin of the word comes from the ancient Greek word biotos (which means life), with the suffix “in” added to form the current word.
Biotin was initially discovered in 1927, however, several decades passed until it was officially recognized as a vitamin.
What is Biotin Made Of?
For the chemistry-inclined among us, here is the composition of biotin.
The biotin molecule is C10H16N2O3S. It is made of a ureido ring fused with a tetrahydrothiophene ring.
A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring.
Bound and Unbound Biotin
In foods, most biotin – vitamin B7 – is bound to various proteins like carboxylases to facilitate the metabolism, or breaking down, of fatty acids, glucose, amino acids, and other substances.
What this means is that it helps the body convert the carbohydrates, fats, and proteins from our foods into the energy we use every day.
Biotin also helps our hair, skin, and nails regenerate easier and get an attractive and fresh appearance. There is a good reason why many people supplement with biotin apart from getting it from food. But more on that further down.
There is also unbound, free biotin, which is more bioavailable to the human body. Usually, this type is found in plants. For example, vegans and vegetarian groups highly emphasize it which they can easily get through simply eating their daily foods.
Popular Biotin Sources
Biotin is found in the following foods in the highest amounts:
- legumes (especially cauliflower)
- sunflower seeds
It can be also found in the form of supplements in three different forms:
- multivitamins which also contain biotin
- B vitamins including also biotin
- Biotin supplements with amounts ranging from 100 mcg all the way up to 10,000 mcg, which is the highest amount I have ever seen biotin as a supplement.
Do note that the content of biotin in foods can vary from season to season, from the soil, as well – in case of supplements – from the way it is produced.
It is interesting to note that, although eggs have a high concentration of biotin, raw egg whites contain a protein called Avidin, which binds it in the small intestine and doesn’t allow it to be properly absorbed.
Thus, if you are in the habit of consuming raw egg white over a long time, supplementing with biotin might avoid health problems down the road.
What Is Biotin Used For?
While one of its primary uses is correcting a biotin deficiency, due to the fact that a lot of foods contain various amounts of it, biotin deficiency is, in fact, quite rare in the human population. So in this context, it is rather used for preventing biotin deficiency.
This can occur, however, especially during pregnancy, malnutrition (especially in various third-world countries), tube-feeding, and fast weight-loss (due to some weight loss supplements or a weight-loss diet).
Since there are no lab tests for determining actual deficiency, it is usually noticed through the following symptoms:
- thining of hair
- red scaly rashes around the eyes, nose, and mouth
- tinglings of the arms and legs
However, unless such extreme cases of deficiency occur, supplementing with this vitamin is, generally, not needed.
On the other hand, while scientific evidence is inconclusive, there is enough anecdotal evidence that taking it as a supplement can help with brittle nails, hair loss, and for getting clear skin.
There have been also various case studies in using biotin for diabetes when taking it along with chromium to lower blood sugar and regulating blood glucose and serum lipid metabolism.
What Are the Recommended Doses of Biotin?
The National Institute of Health recommends the following amounts based on a person’s age
When To Take More Biotin?
There are cases when more is needed than the recommended amounts.
For example, people suffering from biotinidase deficiency, a genetically inherited disorder in which the body cannot process the vitamin biotin due to a deficiency in a particular enzyme.
Pregnant women might also be suffering from slight biotin deficiency.
In addition, people who have a chronic alcohol problem might need to take more of it.
Biotin for Skin, Hair and Nails
For treating brittle nails, there have been a few studies which showed a 91% improvement in nail health after the participants took 2.5 mg of biotin (2,500 mcg) for several months.
There is one aspect that many studies overlook as to why it can be helpful in skin, hair and nails health. Biotin contains sulfur. It is, in fact, the second vitamin to contain sulfur along with vitamin B1 (thiamine).
The human hair is made of keratin, which is a sulfur-containing protein. Keratin is crucial in giving hair its elasticity, strength, and form. A lack of sulfur in hair can cause brittle and broken hair.
Most hair-care online forum, Facebook groups and other gatherings of like-minded people will, at some point or another, focus on biotin and MSM. You only need to stick around for a while in one of these forums to see the results people constantly talk about. The results are usually quite positive.
Sure, these anecdotal cases are easy to dismiss when it comes to scientific studies, however, thousands upon thousands of people who had success with it in getting healthier skin, hair, and nails, should not be dismissed as simply mass hysteria.
Here is one official study on biotin for hair loss which also shows what millions of people have known for a while now: while there is lack of sufficient evidence,
All cases in the study showed evidence of clinical improvement after receiving biotin.
How Much Biotin to Take for Hair Growth?
Most people who take biotin, take it for hair and nail growth. Usually, the highest amount they take is 10,000 mcg per day.
How Long Does Biotin Take to Work?
This question is, again, mostly asked in relation to hair growth. Usually, it takes anywhere between 2 weeks and 2-3 months to see changes when megadosing with it based on a study of women with thinning hair.
The study conclusion was that
The daily administration of a proprietary nutritional supplement significantly increased hair growth after 90 and 180 days. Self-perceived improvements after 90 days were increased after 180 days of additional treatment, suggesting continued improvements may occur with ongoing treatment.
No adverse events were reported. These results may represent the first description of increased hair growth in women associated with the use of a nutritional supplement.
Are There Any Biotin Side Effects?
One piece of information all scientists agree on is that biotin is not toxic. It is not harmful. In fact, even the NIH mentions that “there is no evidence in humans that biotin is toxic at high intakes.”
Also, since it is a water-soluble vitamin, it is easily excreted in the urine. In fact, a 1997 study by Mock and Heird showed that
The urinary excretion and serum concentrations of
biotin and its metabolites increase roughly in the same proportion
in response to either intravenous or oral administration of large
doses of biotin
which translated into everyday English means that
the more biotin we consume, the more we pee out.
That’s why there is usually no danger of overdosing on it or taking too much, which is the same case with all water-soluble B vitamins.
So How Much Biotin is Too Much and What Happens if You Take Too Much?
Another study by Mock in 1996 found that
No reported adverse effects of biotin in humans or animals were
found. Toxicity has not been reported in patients treated with daily
doses up to 200 mg orally and up to 20 mg intravenously to treat
biotin-responsive inborn errors of metabolism and acquired biotin
While the recommended dosage is extremely low, there has not been one proven case of taking too much having an adverse effect on the body.
This is also why it is much easier to get into trouble by taking too many of fat-soluble vitamins, which are usually stored in the body for a longer period of time.
On point worth noting, though, is that taking high doses of biotin might create false readings for lab tests such as the thyroid panel and give incorrect results. Here the vitamin itself will not cause a health risk, but the bad readings might cause the health practitioner deduce wrong results and prescribe a wrong (too high or too low) amount of the medicine needed.
For example, you might end up with too much or too little Levothyroxine (or other thyroid hormones for hypothyroidism, Graves disease, or Hashimoto’s).
Doctor Caroline Greenlee, a renown endocrinologist mentioned the following case:
I saw somebody just yesterday who has had an extensive workup for hyperthyroidism. A lot of her tests look like she has Graves, but she is taking massive doses of biotin. She probably doesn’t have any thyroid problem. We could be treating people for Graves’ disease who don’t have it, and that’s really scary.
It might interfere with medication that is changed and broken down by the liver, including clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig)
It might decrease the effects of these medications. If you are taking any of these pills, ask your doctor if taking the vitamin is recommended.
Some other interactions might be between biotin and other vitamins and amino-acids. For example, this vitamin is an antagonist to both Alpha-Lipoic Acid (ALA) and to vitamin B5 (pantothenic acid).
Alcohol will reduce its absorption rates, and the more alcohol you consume, the less will be absorbed by the body.