Vitamin B7 // Biotin
Vitamin B7 Sources
Biotin is found in many foods, but generally in lower amounts than other water-soluble vitamins. It occurs either as free form that is directly taken up by enterocytes or as biotin bound to dietary proteins. Egg yolk, liver, and yeast are rich sources of biotin.
Whether biotin, which is synthesized by many bacteria normally colonizing the small and large intestine (colon) (39), is released and absorbed by humans in meaningful amounts remains unknown. However, a specialized process for the uptake of free biotin via the human sodium-dependent multivitamin transporter (hSMVT) has been identified in cultured cells derived from the lining of the small bowel and colon (35). This transporter is shared with pantothenic acid.
Vitamin B7 is also available as supplement (D-biotin) in various doses and is often included in B-complex and multivitamin-mineral (MVM) supplements. Many MVM supplements contain 30 μg of biotin (40).
Authored by Dr Peter Engel in 2010, reviewed and revised by Ines Warnke on 28.06.2017