Please help

You can get vitamins and blood tinics most anywhere on the net!  Can I ask what you want blood builders for?  Is your dog anemic?

Johnny's right -- it all depends on WHAT you're buying.

 Many of us don't use "dog vitamins" simply because they tend to be not wonderful quality (inside those little capsules they can be rancid already).  I've even gotten stuff at a vet and had it rancid inside.

 I usually use human quality stuff but you have to be careful to use exactly what your dog needs.  In other words it tends to need to be specific to what your dog needs.  A dog in generally good health may need a supplement rather than actual vitamins.

 But at the same time, an anemic dog or an elderly dog might need something else. 

Both John and I have dogs that have a disease called IMHA -- immune-mediated hemolytic anemia.  So we both tend to connect "blood builder" with anemia.

 But you don't want to give ... well "iron" for example -- to a dog that is otherwise healthy because **too much** iron will become toxic and if the dog isn't somehow anemic or losing blood then you have to beware.

Just help us by being a little more specific about what your dog's situation is and what you need.