For a couple of years I had problems with the vit B`s. (took it for years due to IBS ++)
It started with heavy palpations and insomnia. Took me some time to find out, as it was the least I suspected to be the cause.
In my case I believe it somehow triggered the adrenal fatigue I had. But I never found out why or how.
(this was before iodine, and the first years of iodine; I had to be careful with it)
Still needed some, digestion etc.
Now no problems with taking vit B, adrenals up to par. Once or twice a week.
Yes you can manage without it, or take tiny amounts now and again. I had to take it before food (heaviest meal of the day) never late in the evening. Slowly I was able to tolerate it again.
Some of the old-timers here never took it, did well with Iodine without vit B / ATP factors.