I had a phone consultation with my MO's dietician. After much discussion on other issues, I asked about the calcium at bedtime idea and she had never heard of it.

Like everyone, she advocates spacing out your dosage, that it's better to get it from food than supplements, and that you want to take calcium with Vit D (at the same time) so the D helps the calcium get absorbed. She thought 1200-1400 or 1500 was a good range for total calcium intact---from food and supplements. Too much can cause problems too. (Even too much Vit D can cause problems. She said aim for 30-50 in your blood Vit D test. There has been no proven benefit over 50. Above 70 patients start having problems)

FWIW, I also asked her about black coffee (vs coffee with milk). When I read that coffee/caffeine can leach calcium, I started taking 1/2 a calcium citrate table (166.5 mg) with my black coffee (I don't eat breakfast until much later). She thought that was fine.