Baby Vitamins... vitamin c only or with zinc?

As mothers we always want to provide the best for our little ones and we take extra effort to make sure that our child is properly nourished and healthy especially that they are growing and developing over time. My baby's pedia is my cousin, so I am lucky not to have to buy vitamins for my baby because she just give me samples, and baby cereals too. At this present economic crisis, we need all the help we can get to cut costs, and let us admit it, baby food and vitamins are expensive.
I had been using Ceelin for my baby's vitamin c supplement, but now that he has turned 6 months, my pedia recommended I switch to PedZinc Plus C, this is a vitamin c supplement with zinc. She said that this is anew development in that before, zinc had been too unstable to be included in vitamins and that zinc is important because it boosts the immune system of the body. Now, I was convinced, more so because she gave me a dozen boxes of PedZinc...tee hee...
I looked up the prices of Ceelin and PedZinc and I found that Ceelin is much more expensive than PedZinc, with the added benefits of zinc, I would definitely go with PedZinc. It has been two weeks since my baby started with the new vitamin drops and I noticed that he has better appetite, he finishes his milk faster, eats cereals more and does not sneeze as much.
How many of you have switched to vitamin c with zinc? What have you noticed?