Consider high dose of Biotin as the cause of lab values suggesting Graves disease in a euthyroid individual.
Methods : Patient’s clinical findings and literature review
Case Presentation: A 39-year old male wheelchair bound due to Multiple Sclerosis since 2012 was admitted to the hospital after a fall. His lab workup showed decreased TSH and increased Free thyroxine (FT4). His last thyroid function tests (TFTs) from 2015 were normal. Clinically he was euthyroid. He was taking 10,000 mcg of biotin daily for his Multiple Sclerosis. Physical examination was unremarkable. His heart rate on admission was 45 beats per minute. His TSH and FT4 on the day of admission were 0.03 uIU/mL (0.27-4.20 uIU/mL) and 6.2 ng/dL (0.9-1.8 ng/dL) respectively. His biotin was held at this point. Next day his TSH was 0.48 uIU/mL (0.27-4.20 uIU/mL), FT4 2.1 ng/dL (0.27-4.20 uIU/mL), TSH Receptor Antibody 20.94 IU/L (<=1.75 IU/L), Thyroid Peroxidase Antibodies 92 IU/mL (
Discussion: Biotin is a vitamin normally found in fish, eggs, milk. High dose of Biotin is being used in patients with Multiple Sclerosis with studies showing reversal of MS induced disability in these patients1. Recent studies have shown that high biotin dose leading to thyroid like lab values and that is due to the assay being used in labs these days that all contain biotin and relies on biotin-streptavidin interaction2.
- With use of multivitamins on the rise these days and use of them as part of regimen in different diseases it is best to further investigate and look for any interaction of them with the assays used in the lab.
- Biotin should be held for 2-5 days before hormonal analysis3
- Biotin related analytical interference in endocrine testing is vast and should be assessed in assays including but not limited to TSH, FT4, FT3, intact Parathyroid hormone, Luteinizing hormone4.
American University of Integrative Sciences School of Medicine
Ahmad Akhtar is a third year medical student at AUIS. He graduated with Bachelors in Forensics and Investigative Sciences and a Bachelors in Chemistry. He is currently the CEO of non-profit organization Darul Qalb, that conducts medical mission internationally where procedures like TAVR, PBMV are performed by American Doctors.