Do I have to feed my baby formula to make sure he is getting the right vitamins?

Breast or formula. Breast milk is the best, along with vitamin d or infant multivitamin drops. If you wish to give formula instead or as supplement, infant formulas are designed to be used for the entire first year of life, with all the right vitamins and nutrients. Regular cows milk (or any other milk substitutes) do not have the right balance for infants under 1 year. Check with your doctor about the best choice.
No. The general recommendation is that babies who are mostly breastfed, or completely breastfed, should be given extra vitamin d. It is believed that breastmilk alone may not provide enough vitamin d. Trivisol or polyvisol drops can be used (they also contain some other vitamins). Breastfed babies can get adequate vitamins from the vitamin drops, so these babies don't "have to" drink formula.
No. Simply, no other option. Natural products such as whole milk (cow's milk) and goat's milk lack essential vitamin and mineral. Infant formula has been formulated to be a "well balanced diet" for the infants.
No. Obviously we believe breast milk is best. Infant formulas may have different recipies, but all meet the basic requirements for infant nutrition.Regular cow's milk does not have the right mix of vitamins and nutrients for the baby and should not be used. Thus breast milk or formula are the safest for the baby!
No. Breast milk is best, so there is rarely a reason to have to use formula, assuming nursing is going well. For healthy breastfeeding infants, the only vitamin that you will need to supplement if vitamin d. This vitamin does not cross well in the breast milk. The current recommended dose is 400 iu per day. Vitamin d supplements are sold over the counter, but always talk to your doctor first.
Yes. Breastmilk is a near perfect food for baby. The only thing it's missing is vitamin d, so breast fed babies should get 400 iu of vitamin d a day (1 ml of poly-vi-sol or d-vi-sol). As long as mom is eating a healthful diet and your pediatrician thinks your baby is growing well, you shouldn't have to supplement with formula. Around 4-6 months start giving your baby rice cereal for extra iron.