Buying Vitamins locally?

As I understand we have to take 1500mg Calcium Citrate daily, but not all at once, can only take 500mg at once. And 325mg of Iron (carbonyliron, ferrous fumerat, or gluconate). I already am taking a Multi-Vitamin. Where are people getting these other two locally? I read every bottle at Wal-Mart and got lost Since this is something that has to be taken for a lifetime, has anyone found a good ones that is priced reasonably? Thanks for your time.

I take Citracal with Magnesium...buy it at Walmart. The iron is in my prenatal vitamins and I do not take any additional. My vitamins come from home (Brazil) and have more Iron than the ones I can find here...but I'm sure Walmart has it too. Paola