High-dose cholecalciferol to correct vitamin D deficiency in haemodialysis patients.
BACKGROUND
Vitamin D has emerged as an important survival factor in patients with chronic kidney disease. Non-activated vitamin D may also have beneficial effects on bone, cardiovascular and immune functions. Cholecalciferol is the prevalent non-activated vitamin D in Europe, but there is no valid prospective data available about its use in haemodialysis patients. Thus, we initiated a prospective study to evaluate dosing, safety and tolerability of cholecalciferol supplementation in haemodialysis patients.


METHODS
The prospective study included 64 haemodialysis patients. During replenishment phase patients received 20 000 IU cholecalciferol/week for 9 months. In the open maintenance phase (15 months), patients were randomized to a treated group (20 000 IU cholecalciferol/month) and an untreated group, which did not receive cholecalciferol.


RESULTS
Calcidiol [25(OH)D] deficiency (<37.5 nmol/l; <15 microg/l) was detected in 61/64 patients (95%). During the replenishment phase, calcidiol increased significantly from 16.65 +/- 9.6 to 79.48 +/- 27.15 nmol/l (6.66 +/- 3.84 microug/l to 31.79 +/- 10.86 microg/l) (P < 0.001). Recommended levels (>75 nmol/l; >30 microg/l; K/DOQI) were achieved in 57% of patients. Calcium increased from 2.28 +/- 0.17 to 2.37 +/- 0.19 mmol/l (9.1 +/- 0.69 mg/dl to 9.49 +/- 0.75 mg/dl) (P<0.01). Phosphorus, calcium-phosphorus product and parathyroid hormone showed no significant changes. Fifty-nine patients progressed to the maintenance phase. Analysis per protocol showed a significant drop of calcidiol in the treated [83.98 +/- 31.73 versus 78.5 +/- 38.75 nmol/l (33.59 +/- 12.69 versus 31.4 +/- 15.5 microg/l) (P < 0.001)] and untreated groups [86.35 +/- 40.75 versus 53.4 +/- 26.2 nmol/l (34.54 +/- 16.3 versus 21.36 +/- 10.48 microg/l) (P < 0.001)]. The comparison of the treated and the untreated groups showed no significant differences at the beginning of the maintenance phase: 83.98 +/- 31.73 versus 86.35 +/- 40.75 nmol/l (33.59 +/- 12.69 versus 34.54 +/- 16.3 microg/l). At the end they differed significantly: 78.5 +/- 38.75 versus 53.4 +/- 26.2 nmol/l (31.4 +/- 15.5 versus 21.36 +/- 10.48 microg/l) (P < 0.001).


CONCLUSIONS
Vitamin D deficiency is present in a majority of haemodialysis patients. Supplementation with cholecalciferol is safe, well tolerated and reasonable to replenish vitamin D stores in haemodialysis patients. However, only 57% of patients achieved recommended calcidiol levels, thus favouring additional dose-finding studies.
Tokmak
Faruk
F
Department of Nephrology, Marienhospital Herne, Ruhr University, Bochum, Germany.
Quack
Ivo
I
Schieren
Gisela
G
Sellin
Lorenz
L
Rattensperger
Dirk
D
Holland-Letz
Tim
T
Weiner
Stefan M
SM
Rump
Lars C
LC
D002112:Calcifediol / Q000097:blood; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000009:adverse effects; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy; D008297:Male; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy* / Q000209:etiology
D002762:Cholecalciferol; D002112:Calcifediol