Hello,
In most of the cases, mother's milk makes up for all the requirements of the baby, Vitamin D being the exception. For this the doctor may advice Vitamin D supplement if the baby is drinking 32 ounces of formula milk everyday. And sometimes infants may also have iron deficiency. But in any case, I think you should seek your doctor's advice as whether the baby should be given vitamins and if yes, then in how much quantity.
I am sharing a link with you, please go through it, it may be helpful to you.
http://www.whattoexpect.com/first-year/feeding-your-baby/vitamins-and-babies.aspx