B complex vitamins exceeding RDI : dangerous for chickens ?

[Mrs Wick]

There are so many B complex vitamins, the grat majority of them exceeding the RDI (recommended daily intake).
For example, Nu U nitrition : 1000 times the RDI in B12 vitamin !

What brand do you use ?
Which B vitamins are really useful for chickens with Marek symptoms ?

 

[rosemarythyme]

I have this liquid vit B complex: https://www.vitaminshoppe.com/p/nature-answer-b-complex-16-oz/bb-1436

I have no idea what type of treatment is appropriate for Marek's, I was using this for neurological issues.

B vitamins are water soluble so chickens can stand a bit of overdosing, but I wouldn't use any vitamin regimen for a prolonged period of time.