VitaminWater-soluble

Biotin (B7)

Also known as Vitamin B7, Vitamin H

Biotin, also known as vitamin B7, is a water-soluble vitamin that acts as a coenzyme for carboxylase enzymes, which are essential for metabolizing fats, carbohydrates, and proteins. It also plays a role in gene regulation. Biotin is found in a wide range of foods and is made by gut bacteria, so deficiency is uncommon.

Adequate intake
30
Upper limit
Not established
Type
Water-soluble
Measured in
mcg/day
Intake values verified against the NIH Office of Dietary Supplements and the IOM/NASEM Dietary Reference Intakes.

Why it matters

What it does in your body

  • Serves as a coenzyme for carboxylase enzymes in fat, carbohydrate, and protein metabolism
  • Supports gluconeogenesis and fatty acid synthesis
  • Involved in breaking down certain amino acids
  • Plays a role in gene regulation and cell signaling
  • Contributes to maintenance of healthy skin, hair, and nails

By age, sex, and life stage

How much you need

All values are Adequate Intakes (AI) because there was not enough data to establish RDAs. Values are the same for males and females at every age; needs rise slightly during lactation.

Recommended intake across life

in mcg/day
Infants 0-6 mo
5
Infants 7-12 mo
6
Children 1-3
8
Children 4-8
12
Children 9-13
20
Teens 14-18
25
Adults 19+
30
Pregnancy
30
Lactation
35

Bars scale to the highest recommendation shown. Where men and women differ, both values are listed.

Full reference table

Life stageMaleFemale
Infants 0-6 mo5 (AI)5 (AI)
Infants 7-12 mo6 (AI)6 (AI)
Children 1-38 (AI)8 (AI)
Children 4-812 (AI)12 (AI)
Children 9-1320 (AI)20 (AI)
Teens 14-1825 (AI)25 (AI)
Adults 19+30 (AI)30 (AI)
Pregnancyn/a30 (AI)
Lactationn/a35 (AI)

Values in mcg/day. AI marks an Adequate Intake, used when there is not enough evidence for a formal recommendation.

What moves the number

What changes your needs

Age

The AI rises through childhood and reaches the adult level of 30 mcg per day at age 19.

Sex

The AI is the same for males and females at every age outside of lactation.

Body weight / size

The AI is set per person rather than by body weight; biotin is needed in very small microgram amounts.

Pregnancy and lactation

The AI stays at 30 mcg during pregnancy and rises to 35 mcg during lactation; a share of pregnant women may develop marginal deficiency.

Absorption

Biotin is also produced by gut bacteria. The rare inherited disorder biotinidase deficiency prevents recycling of biotin, and chronic heavy alcohol use lowers levels.

Running low

Signs you might not get enough

Thinning hair, progressing to loss of hair over the bodyScaly, red rash around the eyes, nose, and mouthConjunctivitisDepression, lethargy, and, when severe, hallucinationsIn infants, developmental delays and poor muscle tone

Most at risk: People with the inherited disorder biotinidase deficiency, those with chronic heavy alcohol use, and pregnant and breastfeeding women, a share of whom may develop marginal deficiency.

Too much

Can you get too much?

No toxicity symptoms reported, even at high dosesClinically significant interference with laboratory tests, giving falsely high or low results

Biotin is not toxic even at high doses. The main concern is that supplemental biotin can distort blood test results that use biotin-based technology, potentially leading to misdiagnosis; tell your provider about biotin use before lab testing.

Where to get it

Best food sources

Beef liver, cooked, 3 oz30.8 mcg
Egg, whole, cooked, 1 large10.0 mcg
Salmon, pink, canned, 3 oz5.0 mcg
Pork chop, cooked, 3 oz3.8 mcg
Sunflower seeds, roasted, 1/4 cup2.6 mcg
Sweet potato, cooked, 1/2 cup2.4 mcg
Almonds, roasted, 1/4 cup1.5 mcg

The bottom line

Biotin helps your body turn food into energy and supports healthy skin, hair, and nails. It is found in eggs, liver, fish, seeds, and nuts and is also made by gut bacteria, so deficiency is rare and supplements are usually unnecessary. If you take biotin, tell your doctor before blood work, because it can skew many lab results.

Track biotin (b7) automatically

Biotin (B7) is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.

Sources and method

The recommended intakes, upper limits, and food-source amounts on this page come from the primary references below. Numbers were checked against the current NIH Office of Dietary Supplements fact sheets and the Institute of Medicine (now the National Academies) Dietary Reference Intakes.

  • NIH Office of Dietary Supplements, Biotin Fact Sheet for Health Professionals
  • Institute of Medicine (IOM/NASEM), Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline

This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.