Comparison of the Absorption of Calcium Carbonate and Calcium Citrate after Roux-en-Y Gastric Bypass
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Roux-en-Y gastric bypass (RYGB) restricts food intake. Consequently, patients consume less calcium. In addition, food no longer passes through the duodenum, the main site of calcium absorption. Therefore, calcium absorption is significantly impaired. The goal of this study is to compare two common calcium supplements in gastric bypass patients.
Nineteen patients were enrolled in a randomized, double-blinded, crossover study comparing the absorption of calcium from calcium carbonate and calcium citrate salts. Serum and urine calcium levels were assessed for peak values (C max) and cumulative calcium increment (area under the curve [AUC]). Serum PTH was assessed for minimum values (PTHmin) and cumulative PTH decrement (AUC). Statistical analysis was performed using a repeated analysis of variance model.
Eighteen subjects completed the study. Calcium citrate resulted in a significantly higher serum C max (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02). Calcium citrate resulted in a significantly lower PTHmin (24 + 11 pg/ml vs. 30 + 13 pg/ml, p = 0.01) and a higher AUC (−32 + 51 pg/ml vs. −3 + 56 pg/ml, p = 0.04). There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13 + 36.39 mg/6 h vs. 66.04 + 40.82, p = 0.17).
Calcium citrate has superior bioavailability than calcium carbonate in RYGB patients.
KeywordsRoux-en-Y gastric bypass Obesity Calcium citrate Calcium carbonate
This work was supported by the National Institute of Health (NIH) grants MO1-RR00633 and CTSA UL1-RR024982. The authors would like to acknowledge the editorial assistance of Ms. Hadley Armstrong.
- 1.WHO information sheet and obesity and overweight. 2003Google Scholar
- 2.Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults-the evidence report. National Institutes of Health. Obes Res. 1998;6(Supp 2):51S–209S.Google Scholar
- 4.North American Association for the study of obesity and the National Heart, Lung, and Blood Institute (2000) The practice guide: identification, evaluation, and treatment of overweight and obesity in adults. NIH publication 00-4084Google Scholar
- 21.Patel BN, Passman CM, Fernandez A et al. (2007) Prevalence of hyperoxaluria after modern bariatric surgery. Presented at 25th World Congress of Endurology & SWL 2007Google Scholar
- 37.Heller HJ, Stewart A, Haynes S, Pak CYC. Pharmacokinetics of calcium absorption from two commercial calcium supplements. Am J Clin Pharmacol. 1999;39:1151–4.Google Scholar