Other name(s):

vitamin H (archaic), coenzyme R, d-biotin, hexahydro-2-oxo-1H-thienol[3,4-d]-imidazole-4-pentatonoic acid

General description

Biotin is a B vitamin. It’s water-soluble. It’s easily absorbed when you take it by mouth. It’s found in a variety of foods. It’s also made by bacteria inside the large intestine. Biotin deficiency is rare. Like the other B vitamins, biotin helps your body make energy.

Biotin works with carboxylase enzymes, ATP, and magnesium to use carbon dioxide to help make fatty acids. Biotin also helps make proteins and purines. Biotin helps your body break down carbohydrates and the amino acid tryptophan.

Medically valid uses

Biotin is the treatment for some genetic conditions caused by lack of certain enzymes. These include:

  • Biotinidase deficiency

  • Propionic acidemia

  • Holocarboxylase synthetase deficiency

These conditions can cause neurological damage and abnormal skin conditions. They happen often enough that healthcare providers may start testing for them at birth.

Unsubstantiated claims

There may be benefits that have not yet been proven through research.

Biotin may help treat hair loss (alopecia). It may also treat skin issues. These can include acne, seborrhea, and eczema.

Recommended intake

Biotin is measured in micrograms (mcg). AI is the Adequate Intake.



Infants (0–6 months)

5 mcg 

Infants (7–12 months)

6 mcg 

Children (1–3 years)

8 mcg

Children (4–8 years)

12 mcg

Children (9–13 years)

20 mcg

Children (14–18 years)

25 mcg

Adults (19 years and older)

30 mcg

Pregnant women

30 mcg

Breastfeeding women

35 mcg

Food source

Nutrient content

Beef liver, cooked, 3 ounces

30.8 mcg

Egg, whole, cooked

10 mcg

Salmon, pink, canned in water, 3 ounces

5 mcg

Pork chop, cooked, 3 ounces

3.8 mcg

Hamburger patty, cooked, 3 ounces

3.8 mcg

Sunflower seeds, roasted, ¼ cup

2.6 mcg

Sweet potato, cooked, ½ cup

2.4 mcg

Almonds, roasted, ¼ cup

1.5 mcg

Spinach, boiled, ½ cup

0.5 mcg

Milk, 2%, 1 cup

0.3 mcg

Biotin is stable at room temperature. It doesn’t need to be refrigerated. It isn’t destroyed by cooking.

Biotin deficiency can be caused by:

  • Eating a lot of raw egg whites (more than 6 per day), as egg whites contain a protein (avidin) that blocks the absorption of biotin

  • A weakened immune system

  • Cirrhosis of the liver

  • The genetic condition phenylketonuria (PKU)

  • Taking seizure medicines (anticonvulsants), such as carbamazepine and phenytoin.

  • Chronic alcohol use

  • Certain rare genetic disorders

Women who are pregnant or breastfeeding may need to take supplements, but you should talk with your healthcare provider before doing so.

Biotin deficiency can cause: 

  • Impaired glucose tolerance

  • Loss of appetite

  • Nausea

  • Muscle pain (myalgia)

  • Localized sensory changes (paresthesia)

  • Seborrheic dermatitis

  • Depression

Side effects, toxicity, and interactions

There are no known problems due to too much use of biotin. Extra biotin comes out in urine.

There are no known food or medicine interactions.

Online Medical Reviewer: Bianca Garilli MD
Online Medical Reviewer: Chris Southard RN
Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Date Last Reviewed: 4/1/2023