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Biotinidase Enzyme

Published: July 27, 2026Updated: August 25, 2026

The biotinidase enzyme biomarker measures the activity of the enzyme responsible for recycling biotin, a vital B-vitamin, in the body.

Quick summary

Biotinidase enzyme activity is essential for biotin recycling and deficiency diagnosis.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
U/L
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
FDA Cleared General Assay
interpretation: {"text":"Levels below 3.5 U/L may indicate biotinidase deficiency, requiring further evaluation and potential biotin supplementation.","label":"Low"}; {"text":"Levels within or above the normal range (3.5–10 U/L) typically do not indicate a biotinidase-related issue.","label":"Normal/High"}

Biotinidase is an enzyme that plays a crucial role in the metabolism of biotin, also known as vitamin B7. It catalyzes the release of biotin from dietary proteins and its reutilization in the body.

A deficiency in biotinidase activity can lead to biotin deficiency, which may cause neurological and cutaneous symptoms. Measuring biotinidase enzyme levels helps diagnose such deficiencies.

The normal range for biotinidase enzyme activity is typically between 3.5–10 U/L. Levels below this range may indicate a deficiency, while higher levels are generally not clinically significant.

Frequently asked questions

What are the symptoms of biotinidase deficiency?
Symptoms may include seizures, hypotonia, skin rashes, and hair loss.
How is biotinidase deficiency treated?
Treatment usually involves biotin supplementation to correct the deficiency.
  1. 1
    Biotinidase Deficiency - Genetics Home ReferenceSource
  2. 2
    Biotinidase Enzyme - Lab Tests OnlineSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy