I scouted around the Web a bit and found the following manufacturers who appear to offer the product you seek. Please be advised, I've never used these myself and this is in no way an endorsement of these particular items. You may want to double-check with your doctor that these supplements are suitable for your particular condition before taking (or even ordering) them. Good luck!
Tropical Oasis Calium Citrate
NSI (Nutraceutical Sciences Institute) Calcium Citrate
Vitabase Calcium Liquid
Bluebonnet Liquid Calcium Magnesium Citrate
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