loading dose guidelines 2010
Eur J Endocrinol. 2010 Feb 5. [Epub ahead of print]
Cholecalciferol loading dose guideline for vitamin D deficient adults.

van Groningen L, Opdenoordt S, van Sorge A, Telting D, Giesen A, de Boer H.

L van Groningen, Internal Medicine, Rijnstate Hospital, Arnhem, Netherlands.

Introduction: Severe vitamin D deficiency is very common. Evidence-based guidelines for rapid correction with high dose oral cholecalciferol are not available yet. 
Objective: To develop a practical cholecalciferol loading dose regimen. Materials and methods: 208 vitamin D deficient subjects (serum 25-OH vitamin D3 level < 50 nmol/L), age 18 - 88 years, were treated with solubilised cholecalciferol 50.000 IU/ml. They either received 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 taken at baseline and 10 days after the final dose of cholecalciferol. 
Results: Most patients were severely vitamin D deficient: 76% had a serum 25-OHD3 level < 30 nmol/L at baseline. Cholecalciferol in a cumulative dose of 100.000 IU, 150.000 IU and 200.000 IU increased mean serum 25-OHD3 by 29 nmol/L (95% 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-OHD3 (25-OHD3) was related to the dose per kilogram body weight (R2 = 0.38, P < 0.0001), and is described by the equation 25-OHD3 = 0.025 x (dose per kg body weight). 
Conclusion: The cholecalciferol loading dose required to reach the serum 25-OHD3 target level of 75 nmol/L can be calculated as follows: Dose (IU) = 40 x (75 - serum 25-OHD3) x Body Weight.

PMID: 20139241 [PubMed - as supplied by publisher]