More Calcium Supplements...or a Better Diet?

My calcium urine chemistry shows 8.7 Mmol/D (out of range: 1.2 - 6.2) which means I'm excreting much of my calcium. Does this mean I am not absorbing my calcium supplements and I should be getting calcium through my diet for optimal absorption? Perhaps a pH test (for stomach HCL) would indicate my calcium absorption capability?

I like the information this site provides on low stomach acid and on alkaline diets.