Can taking biotin (Vitamin B7) supplements interfere with laboratory test results, such as troponin and thyroid function tests, and cause false negative results?

Biotin Interference Causing False Negative Laboratory Results

Yes, biotin supplementation can cause clinically dangerous false negative results in critical laboratory tests, most notably cardiac troponin assays, which can lead to missed myocardial infarction diagnoses—a life-threatening scenario. 1

Mechanism of Interference

Biotin interferes with immunoassays that use biotin-streptavidin binding technology through competitive binding mechanisms. 1 The direction of interference depends on the assay format:

• Sandwich (noncompetitive) assays: Biotin causes false negative (falsely decreased) results by blocking streptavidin binding sites 1, 2
• Competitive assays: Biotin causes false positive (falsely elevated) results by competing with biotinylated reagents 1, 2

Critical Tests Affected by False Negatives

Cardiac Troponin (Most Dangerous)

• Troponin I and T assays are particularly vulnerable to biotin interference, producing falsely low results 1, 2
• This represents the most dangerous clinical scenario: falsely low cardiac troponin in patients with acute coronary syndrome can lead to missed myocardial infarction diagnosis 1
• Significant negative interference occurs at biotin concentrations ≥100 ng/mL, with complete signal loss at higher concentrations 3
• The interference is platform-dependent, with Roche Cobas and Siemens platforms showing notable susceptibility 3, 4

Other Tests with False Negative Results (Sandwich Assays)

• Thyroid-stimulating hormone (TSH): Falsely decreased, creating a dangerous pattern when combined with falsely elevated free T4/T3 that mimics hyperthyroidism 2, 5, 4
• Thyroglobulin: Falsely lowered, problematic for thyroid cancer monitoring 5
• Pro-BNP: Falsely decreased 2
• Follicle-stimulating hormone (FSH): Falsely decreased 4
• Luteinizing hormone (LH): Falsely decreased 2

Clinical Timing and Dosing

• Maximal interference occurs 2 hours after biotin ingestion on both single-dose and chronic administration 5
• Even standard over-the-counter doses (10 mg/day) cause significant interference in TSH, free T4, total T3, and thyroglobulin assays 5
• Higher doses used in multiple sclerosis treatment (up to 300 mg/day) cause more severe interference 2

Risk Mitigation Strategies

Pre-analytical Measures

• Instruct patients to discontinue biotin supplementation 48-72 hours before laboratory testing 2
• Document all biotin use in the medical record, including over-the-counter supplements 6
• Time blood draws to avoid peak biotin levels (avoid sampling within 2-5 hours of ingestion) 2, 5

Laboratory Approaches

• Use alternative assay platforms that are less susceptible to biotin interference (Abbott Architect shows less interference than Roche Cobas for thyroid tests) 5
• Consider liquid chromatography-tandem mass spectrometry (LC-MS/MS) for critical measurements, as this method is not affected by biotin 5
• Implement biotin-removing steps prior to analysis when available 2

Clinical Verification

• In females, measure testosterone; in males, measure estradiol—both will be falsely elevated if biotin interference is present 2
• Repeat testing after biotin discontinuation if results are discordant with clinical presentation 2
• For cardiac troponin specifically: if clinical suspicion for acute coronary syndrome is high but troponin is unexpectedly low, directly ask about biotin use and consider serial measurements or alternative diagnostic approaches 1

Special Populations

Multiple Sclerosis Patients

• Discontinuing biotin is discouraged in MS patients on high-dose therapy 2
• Use biotin-insensitive assay platforms or LC-MS/MS methods for these patients 2, 5
• Coordinate timing of blood draws with biotin dosing schedule when possible 2

Common Pitfall

The most dangerous error is assuming normal troponin rules out myocardial infarction without considering biotin interference. Always inquire about biotin supplementation in patients presenting with chest pain or other cardiac symptoms, as this represents a potentially fatal misdiagnosis. 1