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


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 (P < 0.001) in the CaD group and remained constant in the Ca group, while median calcium intake increased above 1200 mg/day in both groups. The percentage of patients with elevated parathyroid hormone levels (> 60 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 < 0.025-0.001). At the end of the study period, biomarkers of bone turnover did not differ between groups.


CONCLUSIONS
A vitamin D3 supplement of 50 microg/day has no additional beneficial effects on markers of bone metabolism in CHF patients with low initial 25-hydroxyvitamin D concentrations if an adequate daily calcium intake is guaranteed.
Schleithoff
S S
SS
Institute of Nutrition and Food Sciences, University of Bonn, Germany.
Zittermann
A
A
Tenderich
G
G
Berthold
H K
HK
Stehle
P
P
Koerfer
R
R
D015415:Biomarkers / Q000032:analysis; D001862:Bone Resorption / Q000378:metabolism; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D004357:Drug Synergism; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*
D015415:Biomarkers; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D015675:Osteocalcin; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium