Combined calcium and vitamin D supplementation is not superior to calcium supplementation alone in improving disturbed bone metabolism in patients with congestive heart failure

Objectives: To clarify the potential role of vitamin D supplementation on bone metabolism in congestive heart failure (CHF) patients with low vitamin D status and insufficient dietary calcium intake. Subjects/Methods: One hundred and two ambulatory male CHF patients were recruited, of whom the majority was treated with loop diuretics. Nine patients died during follow-up. Additional 14 participants dropped out prematurely because their health status worsened markedly. Five patients had to be excluded due to lack of compliance. A daily vitamin D3 supplement plus 500 mg calcium (CaD group) or a placebo plus 500 mg calcium (Ca group) was given for 9 months. Biochemical parameters of vitamin D and bone metabolism were analyzed at baseline and after 9 months. Results: Median 25-hydroxyvitamin D concentrations increased from 41.7 to 103.0 nmol/l (P60 pg/ml), as well as the serum concentration of undercarboxylated osteocalcin, an indicator of osteoporotic fracture risk and the bone resorption marker C-telopeptide fell significantly in both study groups (P