Chicken not able to walk

[Aunt Angus]

It shouldn't cause problems. B vitamins are common in grains and if a chicken gets more than they need, it just gets eliminated in the urates. It's very difficult to overdose on water soluble vitamins. I don't worry about it. You aren't likely to be giving them for more than a few weeks anyway.

I'll give it a go, then, and let you know if anything improves. Worth a shot.