Calcium and vitamin D depletion and elevated parathyroid hormone following biliopancreatic diversion

Background: Biliopancreatic diversion (BPD) is associated with a 70% excess weight loss (EWL) at 10 years, but there are concerns regarding long-term nutritional sequelae. Metabolic bone disease has been documented following Roux-en-Y gastric bypass. Methods: Patients who underwent a BPD from 1998 to 2001 were studied. A questionnaire was designed to review BPD patients and collect information on weight loss, frequency of gastrointestinal disturbances and compliance with multivitamin recommendations. The review included a blood test for vitamin D, parathyroid hormone (PTH), alkaline phosphatase (ALP) and calcium. Results: Of the 82 patients who underwent BPD during this period, the median %EWL at 36 months was 73.0%. 75.6% suffered diarrhea. At median follow-up of 32 months (18-50), 25.9% of patients were hypocalcemic, 50% had low vitamin D, 23.8% had elevated ALP, and 63.1% had elevated PTH, despite 82.9% taking multivitamins. Conclusion: BPD results in significant weight loss. However, 1 in 4 patients are hypocalcemic, and 1 in 2 have a low vitamin D, despite multivitamin supplementation. BPD patients require routine calcium and vitamin D supplementation for life. Long-term sequelae from these abnormal serum levels are not known.