Question

Is it possible to oversupplement vitamin B12 in horses? If I already offer a fortified feed, do I need added vitamin and mineral supplements?

Answer

No recognized deficiency or toxicity level of vitamin B12 in the horse has been established. Vitamin B12 is typically produced by hindgut microbes in sufficient quantities to meet requirements. Additional vitamin B12 may, however, come from a well-fortified feed, especially premium feeds.

To answer your second question, assuming a horse consumes at least the minimum recommended amount of a concentrate, balancer pellet, or vitamin and mineral supplement, no additional supplements will be needed for well-being. Keep in mind, however, that targeted supplementation of certain vitamins might be necessary for certain health concerns. By way of example, biotin has been shown to definitively help some horses grow healthy hooves.