Published in:
01-09-2009 | Clinical Report
Comparison of the Absorption of Calcium Carbonate and Calcium Citrate after Roux-en-Y Gastric Bypass
Published in: Obesity Surgery | Issue 9/2009
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Introduction
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.
Method
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.
Results
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).
Conclusion
Calcium citrate has superior bioavailability than calcium carbonate in RYGB patients.