Stop biotin or all vits B before having tests?

I know this has been mentioned many times before, but just to make sure: is it only vitamin B7 (biotin) that you are supposed to stop a week before having tests, or all vits B?

I am scheduled to go to the lab in the next couple of weeks and want to make sure nothing messes with my results this time...last time (in February) the doctor drew blood in his office and I had taken biotin the previous day. The results showed slightly elevated FT4 levles (24.9; ref 12-22) but FT3 levels well in range. I also had no hyper symptoms. I was told to decrease levo by 25 mcg daily and have not felt as good since. I am by no means hypothyroid but feel slightly less energetic nonetheless. This doctors wants FT4 levels to be around 19-21 in patients on levo only to ensure adequate conversion, so I am wondering if my FT4 levels were actually in range but falsely elevated due to the biotin...?

Are only FT4 affected by biotin, or also FT3?

[SeasideSusie Remembering]

PurpleCat71

Biotin, or B Complex containing Biotin. Stopping 7 days before is enough.

Any blood test can be affected by Biotin, not just thyroid.

[Hidden in reply to SeasideSusie]

Thanks a lot, SeasideSusie!