milk help

Okay ladies so my son has already switched to cows milk I am on WIC I think the lady messed up I thought ur 12 month old was supposed to be on whole vitamin d milk my son was giving 1% and has nothing but the runs since he had reserved vitamin d the month befor and half formula for the transition. But I don't think 1% is Right at all what are u lady's giving the baby. I'm going to go to the store and get vitamin d cause I'm almost positive the lady messed up on what milk to give. My four year old gets 1% my 1year old shouldn't. Right