Vitamin B7 (Biotine)
Biotin is an indispensable component of enzymes responsible for fat, sugar and protein metabolism. Deficiencies lead to skin inflammation, brittle hair and conjunctivitis, among other things.
Good to know about biotin
- The daily requirement is 30-60 µg for women and men.
- Small amounts are produced by bacteria in the intestinal tract
- Biotin has a very low toxicity
- The intake of preparations with biotin can influence the laboratory analysis of thyroid hormones, ferritin, cortisol as well as sex hormones. Therefore, the preparations should be discontinued 1-2 days before the measurement.
- Raw eggs reduce the bioavailability (absorption) of biotin
Indications for biotin
- Biotin deficiency
Biotin status should be determined by urinalysis. Biotin levels in the blood do not decrease and are therefore not meaningful. - Skin, hair and nail diseases
People with dry, scaly skin, eczema, hair loss, and brittle fingernails possibly benefit from a biotin supplement.
Biotin deficiency and its consequences
The following deficiency symptoms may occur:
- Decreased growth, slowed physical and mental development.
- Thin hair, loss of hair (colour), formation of bald patches
- Muscle pain
- Scaly, reddened skin, eczema
- Fatigue, anxiety, depression
Some drugs increase the need for biotin: Drugs used in epileptics reduce absorption and increase degradation and urinary excretion of biotin. High alpha-lipoic acid (antioxidant) doses compete with biotin for binding sites necessary for absorption and probably result in decreased absorption of biotin.
Biotin: the functions in the body
- Fat metabolism
Many important steps in the formation and breakdown of fatty acids depend on biotin-containing enzymes, for example, the conversion of the omega-3 fatty acid α-linolenic acid into the various other omega-3 fatty acids EPA and DHA.
- Build-up of glucose
The first important step in building glucose in the body depends on an enzyme that contains biotin. Building glucose is extremely important to regulate blood sugar levels and prevent hypoglycaemia.
- Regulation of gene expression
Biotin influences the activity of various genetic information, such as DNA-forming proteins (transcription factors), which affect insulin secretion.
Intake recommendations
- Women and men: 30-60 µg daily (DACH* recommendations).
- Pregnant and lactating women: 30-60 µg daily (DACH* recommendations).
*The DACH reference values for nutrient intake are jointly published by the German (D), Austrian (A) and Swiss (CH) Societies for Nutrition.
Biotin in food, per 100 g
| Soybeans | 60 µg | Chicken egg | 25 µg | |
| Porridge | 20 µg | Mushrooms | 16 µg |
The bioavailability of biotin from food is about 50% due to its frequent binding to protein. Biotin from supplements, however, can be absorbed in almost 100%. The proportion of biotin produced by intestinal bacteria is to be considered low.