So, I currently take a multivite in the morning, then two-ish hours later, I take my 2000 IU Vitamin D and the first calcium chew. I take the remaining two calcium chews two hours apart after that.

What's the minimum amount of time you should wait between the vitamins?

the only thing I've heard is you should wait at least two hours between calcium doses (because your body can only absorb around 500 mg at a time) and at least two hours between taking calcium and iron. I take calcium throughout the day and then take my iron before i go to bed so it doesn't interfere with anything.

My multi has iron and I take that with my first meal, along with B12. I wait at least 4 hours to take calcium and D3. It's best to take calcium in 500 mg increments, several hours apart, but I have been using 1000 mg since the beginning and my blood levels are fine. I take it with a bit of dairy (usually yogurt) with D3 in the evening, as I have read that the parathyroids work better at night to absorb calcium. Works for me. Be sure you are using calcium CITRATE, not carbonate.