biotin

What can high-biotin foods do for you?

  • Support healthy skin through proper fat production
  • Help your body make efficient use of sugar
  • Maintain an energy supply in your nerve cells

What events can indicate a need for more high-biotin foods?

  • Skin-related problems, including cradle cap in infants
  • Hair loss
  • Muscle cramps
  • Lack of good muscle tone or coordination

Swiss chard is a good source of biotin.

 

Description

What is biotin?

One of the least well-known of the B-complex vitamins, biotin was originally referred to as "vitamin H." Biotin was discovered in late 1930s and early 1940s research when chicks fed diets high in raw egg white consistently developed skin rashes and lost the hair around their eyes. When egg yolk was added to the chicks' diet, these symptoms disappeared.

Today, we know why. Researchers have identified a substance in raw egg white - a sugar and protein-containing molecule (glycoprotein) called avidin - that can bind together with biotin and prevent its absorption. Food scientists have also identified the egg yolk as one of the most dense sources of biotin in the diet.

How it Functions

What is the function of biotin?

Energy Production

Biotin is involved in the metabolism of both sugar and fat. In sugar metabolism, biotin helps move sugar from its initial stages of processing on to its conversion into usable chemical energy. For this reason, muscle cramps and pains related to physical exertion, which may be the result of the body's inability to use sugar efficiently as fuel, may signal a biotin deficiency. The role of biotin in fat metabolism is discussed below under the heading "Synthesis of Fat (Fatty Acids)."

Synthesis of Fat (Fatty Acids)

Many of the classic biotin deficiency symptoms involve skin-related problems, and the role of biotin in fat synthesis is often cited as a reason for this biotin-skin link. Biotin is required for function of an enzyme in the body called acetyl Co-A carboxylase. This enzyme puts together the building blocks for the production of fat in the body. Fat production is critical for all cells in the body since the membranes of all cells must contain the correct fat components to function properly. Fat production is especially critical for skin cells since they die and must be replaced very rapidly, and also because they are in contact with the outside environment and must serve as a selective barrier. When cellular fat components cannot be made properly due to biotin deficiency, skin cells are among the first cells to develop problems. In infants, the most common biotin-deficiency symptom is cradle cap - a dermatitis (skin condition) in which crusty yellowish/ whitish patches appear around the infant's scalp, head, eyebrows and the skin behind the ears. In adults, the equivalent skin condition is called seborrheic dermatitis, although it can occur in many different locations on the skin.

Support of Nervous System Activity

Because glucose and fat are used for energy within the nervous system, biotin also functions as a supportive vitamin in this area. Numerous nerve-related symptoms have been linked to biotin deficiency. These symptoms include seizures, lack of muscle coordination (ataxia), and lack of good muscle tone (hypotonia).

Deficiency Symptoms

What are deficiency symptoms for biotin?

Skin-related problems, including cradle cap in infants and seborrheic dermatitis in adults, are the most common biotin deficiency-related symptoms.
Hair loss can also be symptomatic of biotin deficiency.
Nervous system-related problems provide the second most common set of biotin-related symptoms, including seizures, lack of muscle coordination (ataxia), and lack of good muscle tone (hypotonia).
Muscle cramps and pains related to physical exertion can be symptomatic of biotin deficiency, reflecting the body's inability to use sugar efficiently as a fuel.

Toxicity Symptoms

What are toxicity symptoms for biotin?

Reports of biotin toxicity have not surfaced in the research literature, despite the use of biotin over extended periods of time in doses as high as 60 milligrams per day. For this reason, in its 1998 recommendations for intake of B-complex vitamins, the Institute of Medicine at the National Academy of Sciences chose not to set a tolerable upper limit (UL) for intake of biotin.

Impact of Cooking, Storage and Processing

How do cooking, storage, or processing affect biotin?

Biotin is relatively stable when exposed to heat, light, and oxygen. Strongly acidic conditions can, however, denature this vitamin. In raw eggs, biotin is typically bound to a sugar-protein molecule (the glycoprotein called avidin), and cannot be absorbed into the body unless the egg is cooked, allowing the biotin to separate from the avidin protein.

Factors that Affect Function

What factors might contribute to a deficiency of biotin?

In addition to lack of biotin-containing foods in the diet, deficient dietary intake of pantothenic acid (vitamin B5) can contribute to a functional biotin deficiency since B5 works together with biotin in many metabolic situations.
Intestinal problems should also be considered as a possible course of biotin deficiency. The connection between biotin and intestinal problems centers on the role of intestinal bacteria. Under appropriate circumstances, bacteria in the large intestine can produce biotin. When intestinal problems create bacterial imbalance, the body is deprived of this alternative source of biotin.
Consumption of raw egg whites can also contribute to biotin deficiency since avidin, a glycoprotein substance in egg white, can bind to biotin and prevent its absorption. The cooking of egg whites disables this binding of biotin by avidin.

Additionally, as many as 50% of pregnant women may be deficient in biotin, a deficiency that may increase the risk of birth defects. Preliminary research found laboratory evidence of biotin deficiency both in the early (first trimester) and late (third trimester) stages of pregnancy.

Drug-Nutrient Interactions

What medications affect biotin?

Anticonvulsant drugs (like carbamazepine) can compromise absorption of biotin.

Nutrient Interactions

How do other nutrients interact with biotin?

Many of chemical reactions in the body requiring biotin also require pantothenic acid (vitamin B5).

Health Conditions

What health conditions require special emphasis on biotin?

Biotin may play a role in the prevention and/or treatment of the following health conditions:

  • Hair loss (alopecia)
  • Intestinal imbalances, including inflammatory bowel syndrome, irritable bowel syndrome, Crohn's disease, ulcerative colitis, and chronic diarrhea
  • Neuromuscular-related conditions, including seizures, ataxias (movements characterized by lack of muscle coordination), and hypotonias (posture and movement characterized by lack of muscle tone)
  • Skin conditions, including cradle cap in infants and seborrheic dermatitis in adults
  • Pregnancy, as there is an increased demand for nutrients placed upon the mother by the growing fetus.

Form in Dietary Supplements

What forms of biotin are found in dietary supplements?

Biotin is found in its simplest chemical form, D-biotin, in virtually all dietary supplements. This form of the vitamin is the only known metabolically active form.

Food Sources

Introduction to Nutrient Rating System Chart

The following chart shows the foods which are either excellent, very good or good sources of this nutrient. Next to each food name you will find the following information: the serving size of the food; the number of calories in one serving; DV% (percent daily value) of the nutrient contained in one serving (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Nutrient Rating System, please click here.

 

World's Healthiest Foods ranked as quality sources of:
biotin
Food Serving
Size
Cals Amount
(mcg)
DV
(%)
Nutrient
Density
World's
Healthiest
Foods Rating
Chard, Boiled 1 cup 35.0 10.50 3.5 1.8 good
World's Healthiest
Foods Rating
Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%

Public Health Recommendations

What are current public health recommendations for biotin?

The Adequate Intake (AI) levels for biotin, set in 1998 by the Institute of Medicine at the National Academy of Sciences, are as follows:

  • 0-6 months: 5 micrograms
  • 6-12 months: 6 micrograms
  • 1-3 years: 8 micrograms
  • 4-8 years: 12 micrograms
  • males 9-13 years: 20 micrograms
  • males 14-18 years: 25 micrograms
  • males 19 years and older: 30 micrograms
  • females 9-13 years: 20 micrograms
  • females 14-18 years: 25 micrograms
  • females 19 years and older: 30 micrograms
  • Pregnant females of any age: 30 micrograms
  • Lactating females of any age: 35 micrograms

References

  • Bland JS, Costarella L, Levin B et al. Clinical nutrition: a functional approach. The Institute for Functional Medicine, Gig Harbor, WA, p.122.
  • Bonjour JP. Biotin. In: Machlin LJ. (Ed.) Handbood of vitamins. Second Edition. Dekker, New York, 1991;393-427.
  • Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995.
  • Mock DM. Biotin. In: Brown M. (Ed.). Present knowledge in nutrition. Sixth edition. International Life Sciences Institute, Washington, DC, 1989;189-207.
  • Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. AmJ Clin Nutr 2002 Feb;75(2):195-9.
  • Sauberlich HE. Interactions of thiamin, riboflavin, and other B-vitamins. Ann NY Acad Sci 1980;355:80.
  • Tannenbaum SR, Young VR. Vitamins and minerals. In: Fennema OR. (Ed). Food chemistry. Second edition. Marcel Dekker, New York, 1985;512.

This page was updated on: 2004-11-21 10:49:26
© 2002 The George Mateljan Foundation