My calcium was low on my last lab, but my magnesium was good. Somehow I'm not absorbing the calcium. My protein levels are always low too even though I eat lots of it. I know with my malabsorption problems this can happen. I might need to take a pre-measured form of calc/mag. like your link mentions. Something that I'm doing, or my body is doing is not right.
I LOVE how you always add the caveat to talk to a doctor first before going on any supplement. How right you are! My doctor wasn't pleased when I said I was thinking of going on D-Ribose because it's unregulated by the FDA so you don't know what's in it. She said that viatmins are pretty safe though. SK mentions Douglas Lab as a source for vitamins and while they cost more, from what I've read, they are the original manufacturer of a lot of the items and don't put lower dosages in or substitute things like the cheaper varieties often do.