Cholecalciferol loading dose guideline for vitamin D-deficient adults.
BACKGROUND
Severe vitamin D deficiency is very common. Evidence-based guidelines for rapid correction with high-dose oral cholecalciferol are not yet available.


OBJECTIVE
To develop a practical cholecalciferol loading dose regimen.


METHODS
A total of 208 vitamin D-deficient subjects (serum 25-hydroxyvitamin D(3) (25-OHD(3)) level <50 nmol/l), aged 18-88 years, were treated with solubilized cholecalciferol, 50,000 IU/ml. They received either 25,000 IU every fortnight for 8 weeks (total dose 100,000 IU), 25,000 IU every week for 6 weeks (total dose 150,000 IU), or 25 000 IU every week for 8 weeks (total dose 200,000 IU). Blood samples were collected at baseline and 10 days after the final dose of cholecalciferol. Results Most patients were severely vitamin D deficient: 76% had a serum 25-OHD(3) level <30 nmol/l at baseline. Cholecalciferol in a cumulative dose of 100,000, 150,000, and 200,000 IU increased mean serum 25-OHD(3) level by 29 nmol/l (95% confidence interval (CI): 23-35 nmol/l), 43 nmol/l (95% CI: 36-50 nmol/l), and 69 nmol/l (95% CI: 64-75 nmol/l) respectively. The change in 25-OHD(3) (Delta25-OHD(3)) was related to the dose per kilogram body weight (R(2)=0.38, P<0.0001), and is described by the equation: Delta25-OHD(3)=0.025x(dose per kg body weight).


CONCLUSIONS
The cholecalciferol loading dose required to reach the serum 25-OHD(3) target level of 75 nmol/l can be calculated as follows: dose (IU)=40x(75-serum 25-OHD(3))xbody weight.
Department of Internal Medicine, Rijnstate Hospital Arnhem, Wagnerlaan 55, 6800 TA Arnhem, The Netherlands.
Lenneke
L
van Groningen
Susanne
S
Opdenoordt
Adriaan
A
van Sorge
Darryl
D
Telting
Astrid
A
Giesen
Hans
H
de Boer
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000097:blood; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D012044:Regression Analysis; D012621:Seasons; D012709:Serum Albumin / Q000032:analysis; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*; D055815:Young Adult
D010281:Parathyroid Hormone; D010710:Phosphates; D012709:Serum Albumin; D002762:Cholecalciferol; D003404:Creatinine; D002118:Calcium