Superior calcium bioavailability of effervescent potassium calcium citrate over tablet formulation of calcium citrate after Roux-en-Y gastric bypass.
BACKGROUND
Calcium supplementation is commonly recommended for patients after Roux-en-Y gastric bypass to avert bone loss. To test the hypothesis that effervescent (liquid) potassium-calcium-citrate (PCC) might be more bioavailable than a tablet formulation of calcium citrate (Citracal Petite), the present study compared a single dose response of the 2 compounds. The present study was conducted at the University of Texas Southwestern Medical School at Dallas.


METHODS
A total of 15 patients who had undergone Roux-en-Y gastric bypass were included in a 2-phase, crossover, randomized study comparing the single-dose bioavailability of PCC versus Citracal Petite. After following a restricted diet for 1 week, the participants ingested either a single dose of 400 mg elemental calcium as PCC or Citracal Petite. Sequential serum and urine samples were collected for a 6-hour period after the dose and analyzed for calcium, parathyroid hormone, and acid-base parameters.


RESULTS
Compared with citracal petite, PCC significantly increased the serum calcium concentrations at 2, 3, and 4 hours after the oral load. The peak to baseline variation and increment in serum calcium (area under the curve) were significantly greater after PCC (P = .015 and P = .002, respectively). Concurrently, the baseline to nadir variation and decrement in serum parathyroid hormone (area over the curve) were significantly greater after PCC (P = .004 and P = .005, respectively). Moreover, compared with Citracal Petite, PCC caused a significantly greater increment in urinary citrate (P < .0001) and potassium (P = .0004) and a significantly lower increase in urinary ammonium (P = .045).


CONCLUSIONS
In patients who have undergone Roux-en-Y gastric bypass, PCC was superior to Citracal Petite in conferring bioavailable calcium and suppressing parathyroid hormone secretion. PCC also provided an alkali load.
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical School, Dallas, Texas. Electronic address: khashayar.sakhaee@utsouthwestern.edu.
Khashayar
K
Sakhaee
Charles
C
Pak
D000328:Adult; D000368:Aged; D064751:Ammonium Compounds / Q000652:urine; D001682:Biological Availability; D002118:Calcium / Q000097:blood; D019355:Calcium Citrate / Q000493:pharmacokinetics*; D019343:Citric Acid / Q000652:urine; D003404:Creatinine / Q000652:urine; D018592:Cross-Over Studies; D005260:Female; D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D010024:Osteoporosis / Q000517:prevention & control*; D010281:Parathyroid Hormone / Q000097:blood; D011188:Potassium / Q000652:urine; D019357:Potassium Citrate / Q000493:pharmacokinetics*; D013607:Tablets
D064751:Ammonium Compounds; D010281:Parathyroid Hormone; D013607:Tablets; D019343:Citric Acid; D003404:Creatinine; D019357:Potassium Citrate; D019355:Calcium Citrate; D011188:Potassium; D002118:Calcium