Have you considered taking calcium/magnesium capsules? The combination typically comes in about a two Ca to one Mg blend. I have a form of familial 'ritis which that helps when taken regularly in the region of 1000mg a day Ca and whatever Mg that turns out to be. Morning and evening seem to work the best.

Calcium alone does not seem to be so effective. I believe it falls under the category of "couldn't hoit" and it's not very expensive.