Effect of Calcium Citrate Versus Calcium Carbonate on Parathyroid Hormone Levels in Patients Undergoing Bariatric...

Parathyroid hormone (PTH) is important in bariatric patients for understandingcalcium homeostasis and bone health. The effects of calcium carbonate and calcium citrate onPTH levels need further investigation in this population. This systematic review and meta-analysis of randomized clinical trials investigated the effect of calcium citrate versus calciumcarbonate on PTH levels in patients undergoing bariatric surgery, using the PRISMA guidelines. Atotal of 227 participants from four studies were included in the meta-analysis. Pooled analysisshowed no significant differences between the effect of calcium citrate versus calcium carbonateon serum calcium levels (WMD: 0.03 mg/dl, 95% CI: -0.04,0.11;I=35.7%) and PTH levels(WMD: 0 pg/ml, 95%CI: -2.81,2.82;I=73.5). Subgroup analysis showed that a single dose of calcium citrate significantly reduced PTH levels better than calcium carbonate (WMD: -1.17, 95%CI: -2.04,-0.29; I2=0%), but no significant difference was observed in chronic interventions (WMD: 2.05, 95% CI: -3.68, 7.78; I =81.4%). Furthermore, single dose of calcium citrate increased serum levels of calcium AUC (WMD: 1.28, 95% CI: 0.58, 1.99; I =0%) and calcium Cmax (WMD: 0.28, 95% CI: 0.19, 0.37; I =0%), and decreased PTH AUC (WMD: -30.65, 95% CI:-45.49, -15.81; I =0%), more than calcium carbonate. In conclusion, a single dose of calcium citrate is superior to calcium carbonate in reducing PTH levels in patients undergoing bariatric surgery, but no difference was observed over time between the formulations.