Biotin

Inhaltsstoff-Glossar

Biotin

What is biotin?

Biotin is also known as vitamin B7 or vitamin H. It belongs to the B-vitamin family and acts as a cofactor for several enzymes involved in the metabolism of carbohydrates, amino acids and fatty acids.

A severe biotin deficiency may contribute to inflammatory changes, neurological symptoms, skin problems and hair loss. Raw egg white contains avidin, a protein that binds biotin and can reduce its absorption when consumed regularly in large amounts.

Despite widespread advertising claims, evidence that additional biotin improves hair, skin or nails in people without a deficiency is limited.

Where does biotin occur naturally?

Biotin is found in small amounts in many foods. Particularly useful sources include:

  • Yeast
  • Chanterelle mushrooms
  • Beef liver
  • Egg yolk
  • Peanuts and peanut butter
  • Legumes
  • Nuts and seeds

The World Health Organization has referred to an adult intake of approximately 30 µg per day, while the German Nutrition Society and the European Food Safety Authority consider around 40 µg per day an adequate intake for healthy adults. The exact individual requirement is not known.

What is biotin’s primary function in the body?

Biotin is a cofactor for carboxylase enzymes that are important in glucose, amino-acid and fatty-acid metabolism. It is also involved in fatty-acid synthesis and therefore indirectly contributes to immune and cellular metabolism.

Biotin may also influence gene regulation through epigenetic mechanisms. Biotin can bind to histones, the proteins around which DNA is packaged, and may thereby affect the activity of selected genes involved in inflammatory signaling.

The body recycles some of its biotin after biotin-dependent enzymes have completed their tasks. Nevertheless, a small amount is lost through urine, so a regular dietary supply remains necessary.

Biotin and the gut microbiome

Some intestinal bacteria can produce biotin, while others require it for growth. This means that biotin availability may influence the composition of the gut microbiome. Animal studies suggest that severe biotin deprivation can contribute to microbial imbalance and hair loss, although the clinical relevance in humans is still being investigated.

Who is at risk of deficiency?

Biotin deficiency is uncommon but may occur in connection with:

  • Long-term consumption of large quantities of raw egg white
  • Chronic alcohol misuse
  • Certain anticonvulsant medicines
  • Inherited defects in biotin metabolism
  • Severe malnutrition
  • Long-term parenteral nutrition without adequate biotin

Does biotin supplementation help?

Biotin supplementation is most clearly useful when a deficiency is present or strongly suspected. In documented deficiency, supplementation may improve symptoms such as hair loss, dermatitis or neurological complaints.

Biotin is generally regarded as having low toxicity, and even comparatively high doses have been used without obvious adverse effects. However, high-dose biotin can interfere with certain laboratory tests, including thyroid, cardiac and hormone assays. This can lead to misleading results.

Anyone taking high-dose biotin should inform their physician and laboratory before blood testing.

Conclusion

Biotin is an essential vitamin involved in macronutrient metabolism and selected gene-regulation processes. Deficiency is rare but can have significant effects. Supplementation is most appropriate when there is a clear need; broad cosmetic benefits in people with normal biotin status are not well established.

Sources