How can you tell if the Vitamin B Complex you got is water soluble?

Question

or is all Vitamin B Complex water soluble no matter what?

Answer 1

Vitamin B is water soluble, unlike vitamin A or E which is fat soluable.  All B is water soluble.

Answer 2

It is a fact that all B complex vitamins are water soluble which are readily secreted in urine through the kidneys.

Another water soluble vitamin is vit C.

Since they are water soluble, they rarely cause hyper-vitaminosis  or vitamin toxicity unlike fat soluble ones (K,E,D,A).