Table 2.

After discontinuation of biotin 10 000 μg (and later, resuming it but holding it for 5 days prior to lab tests), thyroid function tests normalised and the patient was easily adjusted onto the appropriate levothyroxine dose

Date	26/12/2017	22/2/2018	6/4/2018	2/7/2018
TSH	0.54	0.19	0.41	0.45
T4, free	1.46	1.38	0.86	0.90
T4, total	9.85	10.35
T3, free	3.3	3	2.8	2.7
T3, total	102	84

TSH, thyroid-stimulating hormone.