Concerns With Biotin Supplementation Affecting TSH Labs

Answer

Thanks for reaching out! Yes, biotin has been well-documented as being an agent that can cause inaccuracy on certain labs test and this is something the FDA (Food and Drug Administration) has explicitly warned about.

In fact, biotin, sometimes referred to as vitamin B7, has been implicated in potentially causing a number of different lab tests to be inaccurate, including tests for:

• Beta human chorionic gonadotropin (beta–hCG)
• Cortisol
• Creatine kinase
• DHEA-sulfate
• Estradiol
• Folate
• Follicle-stimulating hormone (FSH)
• Prostate-specific antigen (PSA)
• Thyroid-stimulating hormone (TSH)
• Thyroxine (T4)
• Triiodothyronine (T3)

The FDA has this to say:

"Biotin in blood or other samples taken from patients who are ingesting high levels of biotin in dietary supplements can cause clinically significant incorrect lab test results. The FDA has seen an increase in the number of reported adverse events, including one death, related to biotin interference with lab tests. Biotin in patient samples can cause falsely high or falsely low results, depending on the test. Incorrect test results may lead to inappropriate patient management or misdiagnosis. For example, a falsely low result for troponin, a clinically important biomarker to aid in the diagnosis of heart attacks, may lead to a missed diagnosis and potentially serious clinical implications."

There are several theories as to why biotin can affect lab tests (e.g. TSH tests), including:

• Biotin may block test assay signals, leading to falsely elevated test results
• Biotin may compete with biotin-containing complexes the test utilizes, which can lead to falsely low test results.

Exactly which lab tests are potentially affected by biotin, and to what extent, isn't well known and evidence suggests that there may even be variability from test to test.

Pharmacist Thoughts On Your Situation

In your question, you stated your TSH level is 19.3, which would be considered high according to published reference ranges (which can vary based on the source, but 'normal' values are generally reported to be between 0.5 to 5.0 mIU/L).

However, most documented evidence of biotin lab interference shows that biotin causes falsely low TSH values and falsely high values of T4, and T3. This isn't in line with your reported value of TSH being 19.3 mIU/L, which would be considered on the high end.

Additionally, you mentioned you stopped taking biotin 2 weeks before your lab test and this generally would be considered an appropriate amount of time to avoid interference.

While recommendations may differ, it is generally advised to cease consumption of biotin supplements for a designated period, ranging from a minimum of 8 hours to a maximum of 2 days, prior to undergoing laboratory testing to prevent potential interference. It is believed that abstaining from biotin for a duration of 2 weeks should be sufficient to eliminate the possibility of interference with laboratory results.

So, I would certainly recommend speaking with your doctor more about their recommendation for you to start taking thyroid medication if you don't agree with their assessment or seek another opinion. A TSH value of 19.3 mIU/L is high (but not that high), and is an indication of hypothyroidism.

The typical treatment for hypothyroidism is T4 (thyroxine). The usual amount of T4 that an adult needs is about 1.6 micrograms for each kilogram of body weight each day. However, everyone's needs are different and some people may need as little as 25 micrograms per day or as much as 200 micrograms or more.

Final Words

There could certainly be other factors at play in your situation and my answer is based on the limited information provided in your question. If you would like any more information or additional thoughts, please reach back out!