biotin

Foods Richest in biotin

About biotin

Basic description

Biotin is a B-complex vitamin that has been identified as a necessary nutrient for a century, but has only begun to be understood in the past two decades. It has also been previously referred to as coenzyme R, vitamin H, and vitamin B7, with the different names attesting to the confusion surrounding its role in normal metabolism.

Biotin first came to the attention of researchers for what is still its most recognized characteristic: raw egg whites can interfere with biotin nutrition. (For more on this please see the Impact of Cooking, Storage, and Processing section below.) More recently, we have learned about its central role in many pathways of metabolism. Most importantly, we see that biotin plays key roles in fat and sugar metabolism, roles that make deficiency of biotin show up in multiple and unrelated ways.

Major questions remain about the minimum biotin intake needed to prevent deficiency.

Current food composition databases provide only a partial picture of biotin content in commonly eaten foods. Many foods listed as containing no biotin more accurately contain an unknown quantity of the vitamin. Soybeans, mushrooms, and pumpkin and sunflower seeds are examples of foods with substantial amounts of biotin that are not quantified in the databases we use to determine the biotin concentrations in foods.

Some of the difficulty we have in determining the food content of biotin lies in the shortcomings of our methods for biotin analysis in the laboratory. Three primary methods of biotin analysis involve (1) bacterial growth studies, (2) studies in which biotin binds to a protein called avidin (or sometimes streptavidin), and (3) dye-based studies using a chemical called 4’-hydroxyazobenzene-2-carboxylic acid. All three methods have known limitations, and the results of these different methods can be quite inconsistent. Accurate measurement of biotin content in food remains an ongoing analytical challenge.

Among the rated foods, tomatoes rank as an excellent source of biotin, and almonds as a very good source. Five additional very good sources and 13 good sources appear in the food rating chart.

Role in health support

Blood sugar balance

Diets low in biotin impair the production of insulin, a key hormone in the balancing of blood sugar. More recently, researchers have shown that deficiency of biotin also affects the way insulin acts on cells, giving a second reason that low biotin intake potentially creates problems.

Many biotin-containing foods are simultaneously fiber-rich, making them appropriate staples for individuals managing blood glucose. A Spanish clinical trial reported that adding approximately 30g of mixed nuts daily for 12 weeks led to significant improvement in blood sugar control among participants at elevated risk of developing type 2 diabetes.

Skin health

Deficiency of biotin is also known to cause skin rash. This symptom occurs because biotin is necessary to build healthy fats in the skin. These fats keep the skin supple and moist, and when they are gone, the skin becomes flaky and irritated.

A 1940s study demonstrated that increasing biotin-containing foods in the diet of a lactating mother reduced cradle cap symptoms in nursing infants. This finding has not been replicated in modern clinical settings, but lactating individuals may benefit from foods providing both biotin and omega-3 fatty acids, such as salmon and eggs from pasture-raised chickens.

Summary of food sources

Nuts, root vegetables, and eggs are among the best dietary sources of biotin. Each can contain more than a quarter of the daily requirement in a single serving.

Tofu, mushrooms, and many seeds also contain biotin, though their contributions are not fully reflected in the charts on this page. Each of these foods can provide close to 10% of the daily requirement per serving.

Animal foods like milk and meat contribute 2-10% of the daily requirement per serving.

Current food composition databases contain significant gaps in biotin data. Many foods listed as containing no biotin likely contribute measurably to total intake, but exact amounts remain unquantified.

These analytical limitations make it difficult to design a diet plan that guarantees adequate biotin intake on paper. Average adult biotin intake is estimated at roughly double the daily requirement, suggesting that deficiency is uncommon among individuals eating varied diets (see the Risk of Dietary Deficiency section below).

Nutrient rating chart

Introduction to nutrient rating system chart

Read more background information and details of our rating system

WHF ranked as quality sources of
biotin

Food

Serving
Size

Cals

Amount
(mcg)

DRI/DV
(%)

Nutrient
Density

World’s
Healthiest
Foods Rating

Tomatoes

1 cup

32.4

7.20

24

13.3

excellent

Almonds

0.25 cup

132.2

14.72

49

6.7

very good

Eggs

1 each

77.5

8.00

27

6.2

very good

Onions

1 cup

92.4

7.98

27

5.2

very good

Carrots

1 cup

50.0

6.10

20

7.3

very good

Romaine Lettuce

2 cups

16.0

1.79

6

6.7

very good

Cauliflower

1 cup

28.5

1.61

5

3.4

very good

Sweet Potato

1 cup

180.0

8.60

29

2.9

good

Oats

0.25 cup

151.7

7.80

26

3.1

good

Peanuts

0.25 cup

206.9

6.40

21

1.9

good

Walnuts

0.25 cup

196.2

5.70

19

1.7

good

Salmon

4 oz

157.6

4.54

15

1.7

good

Yogurt

1 cup

149.4

3.92

13

1.6

good

Banana

1 medium

105.0

3.07

10

1.8

good

Raspberries

1 cup

64.0

2.34

8

2.2

good

Cow’s milk

4 oz

74.4

2.32

8

1.9

good

Strawberries

1 cup

46.1

1.58

5

2.1

good

Watermelon

1 cup

45.6

1.52

5

2.0

good

Grapefruit

0.50 medium

41.0

1.28

4

1.9

good

Cucumber

1 cup

15.6

0.94

3

3.6

good

World’s Healthiest
Foods Rating

Rule

excellent

DRI/DV>=75% OR
Density>=7.6 AND DRI/DV>=10%

very good

DRI/DV>=50% OR
Density>=3.4 AND DRI/DV>=5%

good

DRI/DV>=25% OR
Density>=1.5 AND DRI/DV>=2.5%

Impact of cooking, storage and processing

Biotin is relatively stable to common cooking techniques. Soaking and boiling beans causes only about 10% biotin loss, substantially less degradation than most other B vitamins experience. Canning is harder on the nutrient, with losses of 40-80% of original biotin content. Most foods that rank as good or better biotin sources are not typically consumed in canned form.

Raw eggs contain avidin, a glycoprotein that binds biotin with exceptional affinity and prevents its absorption. Avidin binds not only the biotin in eggs but also biotin from other foods consumed simultaneously. Cooking denatures avidin, eliminating this binding effect. Raw eggs also carry bacterial contamination risk, which is an independent reason to cook them before eating.

Risk of dietary deficiency

At least compared to the adequate intake recommendation standard, it appears that biotin deficiency is not very common in America. Most estimates have put average biotin intake between 30 and 40 mcg per day, or just above daily requirement.

These estimates carry a systematic limitation: the food composition tables used to calculate biotin intake are often incomplete, which likely produces underestimates. A Canadian study using more thorough food analysis found average intake closer to 60 mcg per day, roughly double the adult daily requirement. This figure is likely more representative of Western dietary patterns, and the risk of deficiency appears small.

Including legumes, nuts, seeds, and vegetables on a regular basis is the most reliable dietary approach to preventing biotin deficiency.

Other circumstances that might contribute to deficiency

As noted above, consumption of raw egg whites can interfere with biotin absorption. This is due to a constituent called avidin which is destroyed by cooking. It is not currently clear how many raw eggs you need to eat, or for how long you’ll have to eat them, to induce a deficiency state. A 2009 report concluded that one man developed symptomatic biotin deficiency from eating the equivalent of two raw egg whites daily for three months. As mentioned previously, we do not recommend intake of raw eggs on any kind of regular basis for safety reasons

A number of medications, including seizure drugs, can contribute to biotin deficiency. This may be the most common reason for biotin deficiency in the United States at this time.

Relationship with other nutrients

Many of the processes involving biotin also require pantothenic acid. Interestingly, these two nutrients are absorbed in the same site in the intestine. There have not been any published reports, however, of negative interaction between dietary biotin and pantothenic acid.

Risk of dietary toxicity

No reports of biotin toxicity from foods have appeared in the published literature for either humans or animals. The National Academy of Sciences found no evidence for biotin toxicity even at doses approaching ten thousand times the adequate intake level. Biotin amounts found in even the most concentrated food sources pose no toxicity concern at normal serving sizes.

Disease checklist

• Hair loss
• Brittle nails
• Skin rash / seborrheic dermatitis / cradle cap
• Diabetes
• Seizures
• Pregnancy

Public health recommendations

In 1998, the Food and Nutrition Board of the National Academy of Sciences established a set of age-specific Adequate Intake (AI) levels for biotin. These are summarized in the chart below. These AI recommendations are used as the reference standard in the charts on this page. These AIs are as follows.

• 0-6 months: 5 mcg
• 6-12 months: 6 mcg
• 1-3 years: 8 mcg
• 4-8 years: 12 mcg
• 9-13 years: 20 mcg
• 14-18 years: 25 mcg
• 19+ years: 30 mcg
• Pregnant women: 30 mcg
• Lactating women: 35 mcg

There is no established Tolerable Upper Intake Level (UL) for biotin. Biotin doses several thousand times the AI have been used in clinical settings without reported adverse effects, making dietary biotin toxicity extremely unlikely.

The Daily Value (DV) for biotin was established by the U.S. Food and Drug Administration at 300 mcg per day per 2000 calories. This DV is dramatically higher than the newer National Academy of Sciences recommendation. The WHF recommended intake level for biotin uses the National Academy of Sciences standard of 30 micrograms for adults 19 and older, reflecting the more recent research base.

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.

The explanation involves avidin, a glycoprotein in raw egg white that binds biotin with extraordinary affinity and prevents its absorption. Egg yolk, by contrast, is one of the most concentrated dietary sources of biotin.

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.

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.

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.

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 has been studied in connection with 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.

Food sources

What foods provide biotin?

Swiss chard is a good source of biotin.

Related Articles

• Can salads be a good source of nutrients?
• Veggie Advisor: How does our Vegetable Advisor make personal recommendations?
• Veggie Advisor
• What are the pros and cons of raw eggs?
• What's New and Upcoming in 2014
• Which foods are classified as "nightshades," and why are adverse reactions sometimes associated with these foods?

References

1. Ball, GFM. Biotin. In: Vitamins In Foods: Analysis, Bioavailability, and Stability. CRC Press, Boca Raton, FL, 220-30; 2005.
2. Cammalleri L, Bentivegna P, Malaguarnera M. Egg white injury. Intern Emerg Med 2009;4:79-81. https://doi.org/10.1001/jama.1942.02830140029009
3. Casas-Aqustench P, Lopez-Uriarte P, Bullo M, et al. Effects of one serving of mixed nuts on serum lipids, insulin resistance and inflammatory markers in patients with the metabolic syndrome. Nutr Metab Cardiovasc Dis 2001;21:126-35. https://doi.org/10.1016/j.numecd.2009.08.005
4. Food and Nutrition Board, Institute of Medicine. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academy Press; 1998;58-86.
5. Larrieta E, Vega-Monroy ML, Vital P, et al. Effects of biotin deficiency on pancreatic islet morphology, insulin sensitivity and glucose homeostasis. J Nutr Biochem 2012;23:392-9. https://doi.org/10.1016/j.jnutbio.2011.01.003
6. Mock DM. Marginal biotin deficiency is common in normal human pregnancy and is highly teratogenic in mice. J Nutr 2009;139:154-7. https://doi.org/10.3945/jn.108.095273
7. Said HM. Biotin: the forgotten vitamin. Am J Clin Nutr 2002;75:179-80. https://doi.org/10.1093/ajcn/75.2.179
8. Staggs CG, Sealey WM, McCabe BJ, et al. Determination of the biotin content of select foods using accurate and sensitive HPLC / avidin binding. J Food Compost Anal 2004;17:767-76. https://doi.org/10.1016/j.jfca.2003.09.015
9. Stratton SL, Horvath TD, Boqusiewicz A, et al. Plasma concentration of 3-hydroxyisovaleryl carnitine is an earlyl and sensitive indicator of marginal biotin deficiency in humans. Am J Clin Nutr 2010;92:1399-405.
10. Zempleni J, Wijeratne SKS, and Hassan YI. Biotin. Biofactors 2009, 35(1): 36-46. doi:10.1002/biof.8. https://doi.org/10.1002/biof.8
11. Bland JS, Costarella L, Levin B et al. Clinical nutrition: a functional approach. The Institute for Functional Medicine, Gig Harbor, WA, p.122. 1999. https://doi.org/10.3390/jcm8071065
12. Bonjour JP. Biotin. In: Machlin LJ. (Ed.) Handbood of vitamins. Second Edition. Dekker, New York, 1991;393-427. 1991.
13. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995. 1995.
14. Mock DM. Biotin. In: Brown M. (Ed.). Present knowledge in nutrition. Sixth edition. International Life Sciences Institute, Washington, DC, 1989;189-207. 1989.
15. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. AmJ Clin Nutr 2002 Feb;75(2):195-9. 2002. https://doi.org/10.1093/ajcn/75.2.295
16. Sauberlich HE. Interactions of thiamin, riboflavin, and other B-vitamins. Ann NY Acad Sci 1980;355:80. 1980. https://doi.org/10.1111/j.1749-6632.1980.tb21329.x
17. Tannenbaum SR, Young VR. Vitamins and minerals. In: Fennema OR. (Ed). Food chemistry. Second edition. Marcel Dekker, New York, 1985;512. 1985.
18. Bonjour JP. Biotin. In: Machlin LJ. (Ed.) Handbood of vitamins. Second Edition. Dekker, New York, 1991;393-427 1991.
19. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995 1995.
20. Mock DM. Biotin. In: Brown M. (Ed.). Present knowledge in nutrition. Sixth edition. International Life Sciences Institute, Washington, DC, 1989;189-207 1989.
21. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. AmJ Clin Nutr 2002 Feb;75(2):195-9 2002. https://doi.org/10.1093/ajcn/75.2.295
22. Sauberlich HE. Interactions of thiamin, riboflavin, and other B-vitamins. Ann NY Acad Sci 1980;355:80 1980. https://doi.org/10.1111/j.1749-6632.1980.tb21329.x
23. Tannenbaum SR, Young VR. Vitamins and minerals. In: Fennema OR. (Ed). Food chemistry. Second edition. Marcel Dekker, New York, 1985;512 1985.