The biotin question

The water-soluble vitamin D-biotin belongs to the class of B vitamins and is used as an ingredient in drugs to treat various diseases, and as a dietary supplement to ensure sufficient daily intake. There are also a number of combination products that contain D-biotin.

A Dear Doctor Letter issued in Germany in May 2019 and a statement released by the German Federal Institute for Risk Assessment (Bundesinstitut für Risikobewertung – BfR) in November 2019 both indicate that biotin may interfere with clinical laboratory testing. For example, biotin substitution may cause either falsely low or falsely high results in laboratory tests that employ a biotin-streptavidin interaction as part of the test procedure. However, this has so far only been observed at very high dosages.

The average adequate intake for D-biotin is defined as 30-60 µg per day. While the biotin content in most dietary supplements is based on this figure, with daily dosages of up to 150 µg of D-biotin, some products may contain higher doses. Drugs used to treat biotin deficiencies, hair and nail growth disorders, and autoimmune diseases may contain 100 mg to 300 mg of D-biotin (i.e. approx. 10,000 times the daily required amount). These high dosages have demonstrably been shown to cause incorrect laboratory results.

However, the publications issued by the German Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte – BfArM) and the Federal Institute for Risk Assessment appear to suggest that interference may occur at doses as low as 150 µg per day. It is not clear where this figure originated because, as the BfArM mentions in passing, there is no actual data for amounts as low as these.

Speaking from long-standing experience, our partner laboratory GANZIMMUN Diagnostics AG has no concerns about any possible effects of dosages lower than 150 µg per day on laboratory tests. We share this view.

With the exception of four products, Biogena supplements contain less than 150 µg of biotin per daily dose. This means that you do not need to stop taking them before giving a blood sample.

Here is an overview of the Biogena products that contain more than 150 µg per daily dose:

Conclusion: It is of course important for government agencies to inform the public about possible interference between biotin and immunoassays. It would, however, be advisable to pay more attention to dosages and to define them more precisely. Otherwise, this is bound to create uncertainty – at the expense of patients and their healthcare practitioners.