Biotin Supplements Can Mess Up Your Hormone Tests

observational-study PMID: 34736903

Quick Summary: Taking high doses of biotin supplements can sometimes give inaccurate results on certain blood tests for hormones like vitamin D, thyroid, and parathyroid. This study found that a special lab process can fix the problem.

Does Biotin Affect Blood Tests?

Yes, it can! This research looked at how biotin, a popular supplement for hair, skin, and nails, affects the accuracy of certain blood tests. The study found that high levels of biotin can interfere with some tests, leading to incorrect results. This is especially true for tests done using a specific type of lab equipment (Roche Diagnostics assays).

Study Details

Who was studied: 50 children with a rare condition called biotinidase deficiency. They were already taking biotin supplements as part of their treatment.

How long: The study looked at blood samples taken at one point in time, before and after a special lab process.

What they took: The children were taking 5-20 mg of biotin daily.

What This Means For You

If you take biotin supplements: Tell your doctor before any blood tests, especially if they're checking your vitamin D, thyroid, or parathyroid hormone levels.

Why it matters: Inaccurate test results could lead to a wrong diagnosis or treatment. For example, you might be told you have a vitamin D deficiency when you don't.

What your doctor can do: Your doctor might use a different type of test that isn't affected by biotin, or they might ask you to stop taking biotin for a few days before the test.

Study Limitations

Specific Group: This study focused on children with a specific condition taking high doses of biotin. The results might not apply to everyone.

Lab Process: The study used a special lab process to fix the problem. This isn't something you can do at home.

Test Types: The study only looked at a few specific types of tests. Other tests might be affected differently.

Key Findings

This study demonstrates that high-dose biotin therapy (5–20 mg/day) in children with biotinidase deficiency (BTD) significantly interferes with Roche Diagnostics immunoassays for 25-hydroxy vitamin D (25-OHD), parathyroid hormone (PTH), and thyroid-stimulating hormone (TSH), but not with Beckman Coulter assays, HPLC, or LC/MS-MS methods. Post-neutralization with Streptavidin-coated magnetic particles (SMP), Roche assay results for 25-OHD decreased by 67.7% (from 90.2 to 29.1 ng/mL, p < 0.0001), PTH increased by 260% (from 7.8 to 28.2 pg/mL, p < 0.0001), and TSH rose by 16.1% (from 2.36 to 2.74 mIU/L, p < 0.0001). Biotin concentrations averaged 175.2 μg/L. Beckman Coulter assays showed no significant interference.

Study Design

An observational study involving 50 children (age range unspecified) with BTD receiving biotin therapy. Blood samples were analyzed pre- and post-biotin neutralization using SMP. Hormone levels were measured via four methods: Roche and Beckman immunoassays, HPLC, and LC/MS-MS. The study focused on within-subject changes after neutralization, with no control group.

Dosage & Administration

Participants received daily oral biotin doses of 5–20 mg, consistent with standard BTD treatment protocols. Biotin neutralization was performed in vitro using Streptavidin-coated magnetic particles, not administered to patients.

Results & Efficacy

25-OHD: Roche assay showed a median decrease of 61.1 ng/mL post-neutralization (90.2 vs. 29.1 ng/mL, p < 0.0001). Beckman, HPLC, and LC/MS-MS showed no significant differences.
PTH: Roche assay detected a 20.4 pg/mL median increase after neutralization (7.8 vs. 28.2 pg/mL, p < 0.0001). Beckman assay results remained stable.
TSH: Roche assay revealed a 0.38 mIU/L median rise post-neutralization (2.36 vs. 2.74 mIU/L, p < 0.0001).
Interference thresholds: Biotin concentrations ≥51.4 μg/L (PTH) and ≥62.9 μg/L (25-OHD) triggered clinically relevant Roche assay interference.

Limitations

Population specificity: Results apply only to children with BTD on high-dose biotin, not healthy individuals or adults.
Observational design: Cannot establish causality, though associations are statistically robust.
In vitro neutralization: SMP application occurred in lab settings; real-world clinical neutralization may vary.
Assay variability: Only four methods tested; other platforms (e.g., Siemens, Abbott) may respond differently to biotin.
No baseline comparator: Lacks untreated BTD controls to confirm pre-neutralization accuracy.

Clinical Relevance

High-dose biotin (>5 mg/day) can lead to false hormone readings in Roche immunoassays, risking misdiagnosis of vitamin D deficiency, hypoparathyroidism, or thyroid dysfunction. Clinicians should consider biotin interference when interpreting hormone tests in patients on biotin therapy and opt for non-biotinylated assays (e.g., Beckman, LC/MS-MS) or use SMP neutralization to ensure accuracy. Patients should disclose biotin supplementation prior to lab testing. This study underscores the need for standardized protocols to address biotin interference in clinical diagnostics.

Source: PubMed (2022)
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