Short Term Omeprazole Use and Markers of Calcium Homeostasis

Objective: Several studies indicate a higher prevalence of fracture following long term utilization of proton pump inhibitors (PPIs), among them omeprazole is the most widely used. However, the exact mechanisms leading to this complication are largely unknown. We studied short term effects of omeprazole on some markers of calcium metabolism. Material and Methods: In thirty young adult patients with gastroesophageal reflux, omeprazole was prescribed at 20 mg twice daily for thirty days. Baseline characteristics, as well as data after treatment with omeprazole, were compared. We also measure important parameters in sixty age and sex match healthy individuals at baseline. Results: The mean age of patients was 31.8 year and there was no significant difference regarding age, sex, Body mass index (BMI), serum calcium, serum alkaline phosphatase and Parathyroid hormone (PTH) between cases and controls. Although, most of the patients were vitamin D deficient (mean = 29.7 nmol/l); compared to controls serum 25 OH Vitamin D was higher (P= 0.005) and serum phosphate was lower (P= 0.001) in patients. In addition, there was a significant increase in alkaline phosphatase (P=0.01) and borderline decrease in serum calcium (P= 0.057), thirty days after treatment with omeprazole. Conclusions: High dose omeprazole after thirty days in the presence of vitamin D deficiency affects bone turnover probably by decreasing calcium absorption.