Gastrointestinal bacteria usually produce enough biotin to meet bodily needs. Many foods also contain small amounts of biotin, including whole wheat, egg yolks, nuts, and legumes.
Biotin and hair growth
While biotin has become popular for treating hair loss, there is little evidence to support its benefits.
Dermatologic and pediatric communities in the United States once recommended the use of biotin for hair growth. Biotin is also called vitamin H, for "Haar und Haut", which means "hair and skin" in German.
However, there have never been any clinical trials to support the use of biotin supplementation to improve hair health, except in people born with deficiencies.
While studies have shown that biotin deficiencies can lead to alopecia or hair loss researchers still do not fully understand why.
Part of the reason biotin supplementation may not be beneficial to hair health is that biotin deficiencies are considered rare.
The average intake in Western countries is small, an estimated 35-70 micrograms per day (mcg/day).
The U.S. Food and Drug Administration (FDA) do not have a daily recommended dietary allowance for biotin. And, most people in the U.S. get more than enough biotin naturally from gastrointestinal bacteria and their diet.
Currently, biotin supplementation is only recommended for people with biotin deficiencies and pregnant or breast-feeding women.
For infants born with biotin deficiencies, the recommended supplemental dose is 10-30 mcg/day. Individuals over the age of 10 years with biotin deficiencies should consume between 30-100 mcg/daily.
Brand names for approved biotin supplements in the U.S. include:
Causes of biotin deficiency
Alcohol may contribute to a biotin deficiency, which may inhibit healthy hair growth.
Anything that causes malnutrition or interferes with gastrointestinal function can contribute to the development of a biotin deficiency. Deficiencies are also associated with several inherited conditions.
Factors that contribute to or cause biotin deficiencies include:
- lack of biotin in parental diet during pregnancy or breast-feeding
- inherited conditions that cause a deficiency in enzymes needed for biotin to work or be released from foods
- too much avidin, a compound that impairs biotin absorption, commonly found in foods, such as raw eggs
- long-term use of anticonvulsant medications
- gastrointestinal conditions that prevent the absorption of biotin
- chronic use of alcohol or intravenous drugs
- Isotretinoin, an acne medication
- gastrectomy or partial gastrectomy
- severe or chronic malnutrition, more common in people over 65 years, extreme athletes, and those with anorexia or bulimia
Warning signs of deficiency
Though biotin deficiencies are considered rare among Americans, when severe the condition can pose serious health risks.
Warning signs of biotin deficiency include:
- hair loss
- confusion or memory problems
- skin rash, especially around the nose and mouth
- nausea and abdominal cramping
- muscle pain and cramping
Foods that contain biotin
Nuts are a good source of biotin, iron, and omega fats, which may support healthy hair growth.
Foods with a notable concentration of biotin include:
- egg yolk
- pork liver
- oat flakes
- wheat germ and whole-grains
- nuts and legumes
- white mushrooms
- spinach and cauliflower
- cheese, curds, and cow's milk
- pork, beef, and chicken
- apples, bananas, and tomatoes
- carrots, lettuce, and potatoes
Other natural remedies for hair growth
Similarly to biotin, many other nutritional supplements claim to improve hair health despite a lack of scientific support. Many herbal products marketed as hair growth formulas also contain biotin, as part of a mixture.
Popular nutrients that may also help with hair growth and thickness include:
- vitamin A
- saw palmetto
- horsetail (Equisetum arvense sp.)
- acerola cherry (Malpighia glabra)
- vitamin C
Although there is no firm scientific evidence to support the use of biotin supplements to improve hair health, there is also relatively little risk associated with using them.
There are no reported cases of adverse reactions from biotin supplementation, even when given in high doses to babies.
Unlike many other nutritional supplements, biotin supplements do not carry a risk of toxicity or overdose.
It is important for individuals experiencing unexpected or unusual hair loss to speak to a doctor. In most cases, biotin deficiencies are not the cause of hair loss, but they may be a contributing factor.
For persistent or severe cases of hair loss, prescription medications may be recommended.
Currently, the only two medications approved by the FDA for hair loss are topical minoxidil and oral finasteride.