Anyone have or had this situation. I have Osteoporosis and started taking Calcium (200 - 1500)and vitamin D3 (3400) per day. I had low D. I started eating a lot of green leafy vegatables and upped my exercise. Had a blood test 2 months to check D level and Comp. Metabolic Panel. The CO2, venous level came back 32 was suppose to be 30 or below. The doctor was not concerned about that. I had all these tests done before I started Strontium Citrate and other supplements so I had a starting point if anything did go wrong. I just had another panel done (2 months later) to see how these new supplements were reacting. Everything was perfect except the CO2, venous which was 31 now down from 32. Again they were not concerned about this. I have never had this test come back slightly high. Could it be the big change in my diet, Vegtables, all good foods, etc. and the Calcium and D? Is my body just trying to regulate itself now? The Strontium and other supplements were not a factor and the score did go down 1 point. Thanks for your thoughts.