What Is Biotin? Everything You Need to Know About Vitamin B7, Its Benefits, Food Sources, and Recommended Dosages

Biotin, also known as vitamin B7 or vitamin H, is a water-soluble B vitamin that is essential for the body. It helps convert food into energy, supports the nervous system, and contributes to healthy skin, hair, and nails. Because of these properties, biotin is often called the "beauty vitamin."

Functions of biotin in the body

Biotin helps the body:
> Obtain energy from food – it participates in the metabolism of carbohydrates, fats, and proteins. Maintain hair, skin, and nails – it can help prevent hair loss, brittleness, and dryness.
> The nervous system – contributes to normal nerve impulse transmission.
> Simply put, biotin helps the body use food for energy and supports beauty and well-being. 

Sources of biotin in food

Biotin is naturally found in many foods, but the highest amounts are found in:
> eggs (especially egg yolks)
> liver and other offal
> fish (salmon, tuna)
> nuts (almonds, peanuts)
> seeds (sunflower seeds)
> sweet potatoes, spinach, broccoli 
Important: the protein avidin found in raw egg whites interferes with the absorption of biotin, but this effect is lost when the egg whites are heat-treated.

Recommended biotin intake

According to data from the European Food Safety Authority, 2014:
Adults: 40 µg per day
Pregnant women: 40 µg per day
Breastfeeding women: 45 µg per day
Children: from 20 µg (1-3 years) to 35 µg (adolescents)
*µg - micrograms

Symptoms of biotin deficiency

Biotin deficiency is rare, but may manifest as:
> hair loss or complete baldness
> dry, red, scaly skin around the eyes, nose, mouth, and genitals
> fatigue, apathy, depression
> numbness and tingling in the hands and feet
> coordination problems, convulsions
> weak immune system

Risk groups that may experience biotin deficiency:

> pregnant women
> people receiving long-term intravenous nutrition
> infants receiving biotin deficiency from breast milk
> people with digestive disorders, inflammatory bowel diseases
> smokers
> people taking antiepileptic drugs (phenobarbital, phenytoin, carbamazepine)
> people with liver disease

Biotin and hair, nail, and skin health

Biotin is often used for beauty reasons. Studies show that 1.5 mg of biotin per day can help strengthen nails and hair.

Biotin and blood sugar control

Studies in people with type 1 and type 2 diabetes suggest that biotin may help lower blood glucose levels. Animal studies in 2013 showed that biotin may promote insulin secretion and lower blood sugar levels. Studies from 2016 suggest that biotin may help control glucose in people with type 1 diabetes, but more clinical studies are needed. Study data taken from studies conducted by the US National Institutes of Health.

Biotin and neuropathy

Biotin is essential for maintaining nerve function. Studies show that:
> Biotin may help reduce nerve damage in patients with diabetes or undergoing dialysis, although most data comes from animal studies.
> In 1990, three patients were reported to have experienced symptom improvement after receiving high doses of biotin for 1–2 years.
> Studies in 2021 suggest a possible benefit for neuropathic pain, although the studies have only been conducted on mice.

Biotin and rare diseases

Biotin-responsive basal ganglia disease is a rare inherited disorder that may respond to treatment with a combination of thiamine and biotin.
Treatment of multiple sclerosis – Some studies suggest that high doses of biotin may improve symptoms in MS patients. Studies from 2016 suggest that a high dose three times a day for 9 months reduced symptoms in some participants.

Is it worth taking biotin supplements?

Most people get enough biotin from their diet, so supplements are not necessary. However, they may be beneficial:
> for stronger hair and nails,
> during pregnancy or breastfeeding,
> for diabetes or other specific conditions (only under medical supervision).

Biotin and beauty supplements

Many women take biotin as a hair-strengthening supplement. Biotin is often combined with other beauty supplements, such as drinkable collagen, because they work synergistically—together, they help maintain skin elasticity, stronger hair, and firmer nails. Taking these supplements can be especially helpful for women who want to boost the effects of their beauty routine along with a balanced diet.

Side effects of biotin

Biotin is safe even in high doses. No toxic effects have been found even at doses of up to 200 mg per day. However, very high doses can distort the results of some blood tests, especially hormone or heart biomarker tests.
Biotin is a vitamin that helps the body produce energy, maintains hair, nails, and skin, and may support nervous system function. A balanced diet usually meets your needs, but supplements may be beneficial in certain situations, especially during pregnancy, breastfeeding, or specific health conditions.