Chapter 9. Micronutrients for Energy

Biotin (B7)

The Function of Biotin (B7)

Biotin is required as a coenzyme in fatty acid synthesis, gluconeogenesis, and carbohydrate, lipid, and protein metabolism. It is also required as an enzyme in the synthesis of some nonessential amino acids. A specific enzyme, biotinidase, is required to release biotin from protein so it can be absorbed in the gut. Some bacterial synthesis of biotin occurs in the colon; however, this is not a significant source of biotin.

Dietary Reference Intakes for Biotin (B7)

Because there is little information on the requirements for biotin, the Adequate Intakes (AI) is based on the observed dietary intakes in healthy population groups. The AI for different age groups for biotin is listed in Table 9.11 “Dietary reference intakes for biotin.”

Table 9.11: Dietary reference intakes for biotin
Age Group AI Males and Females mcg/day)
Infants (0–6 months) 5
Infants (7–12 months) 6
Children (1–3 years) 8
Children (4–8 years) 12
Children (9–13 years) 20
Adolescents (14–18 years) 25
Adults (> 19 years) 30
Data Source: (“Biotin,” 2017)[1]

Dietary Sources of Biotin (B7)

Biotin can be found in foods such as eggs, fish, meat, seeds, nuts and certain vegetables. For the biotin content of various foods, see Table 9.12 “Biotin content of various foods.”

Table 9.12: Biotin content of various foods
Food Serving Biotin (mcg) Percent Daily Value*
Eggs 1 large 10 33.3
Salmon, canned 3 oz. 5 16.6
Pork chop 3 oz. 3.8 12.6
Sunflower seeds ¼ c. 2.6 8.6
Sweet potato ½ c. 2.4 8
Almonds ¼ c. 1.5 5
Tuna, canned 3 oz. 0.6 2
Broccoli ½ c. 0.4 1.3
Banana ½ c. 0.2 0.6
* Current AI used to determine Percent Daily Value
Data Source: (“Biotin,” 2017)[2]

Consuming Too Little Biotin

Biotin deficiency is rare but can be caused by eating large amounts of egg whites over an extended period of time. This is because a protein in egg whites tightly binds to biotin, making it unavailable for absorption. A rare genetic disease-causing malfunction of the biotinidase enzyme also results in biotin deficiency. Symptoms of biotin deficiency are similar to those of other B vitamins, but may also include hair loss when severe. Other deficiency symptoms include a red, scaly rash around the eyes, nose, and mouth, depression, and hallucinations.

Consuming Too Much Biotin

There are no known adverse effects from consuming an excess of biotin.


  1. Fact Sheet for Health Professionals: Biotin. National Institute of Health, Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/. Updated October 3, 2017. Accessed November 10, 2017.
  2. Fact Sheet for Health Professionals: Biotin. National Institute of Health, Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/. Updated October 3, 2017. Accessed November 10, 2017.

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