I really like AAFP websites. I often refer to the B12 one and the Hip pain one. Those are both good too.

Here is the one you should look at. You CAN have your blood calcium measured, while doing the D supplements to see if you are absorbing too much calcium from your food or any supplements.

http://www.aafp.org/afp/2003/0501/p1959.html

I personally don't think a person needs much supplemental calcium if they eat well...foods high in calcium etc. ... while taking Vit D3.

Some of the above article is complicated but I find the chart in the beginning easily understandable for most people reading here. You can give this medical site to your doctor too, since that is the real target for the link. Written by doctors for doctors.

Here is what the vitaminDcouncil says about toxicity potential:

http://www.vitamindcouncil.org/about...in-d-toxicity/

So I think you can appease your doctor by having testing done, at the time you test your D and other things.

IMO the difference between 1000 IU and 2000 IU is tiny in the scheme of things. 2000IU is what is now recommended for people NOT tested yet, in fact.