Hindawi Publishing Corporation International Journal of Endocrinology Volume 2013, Article ID 327265, 8 pages http://dx.doi.org/10.1155/2013/327265 Clinical Study A Randomised, Double-Blinded, Placebo-Controlled, Parallel Study of Vitamin D3 Supplementation with Different Schemes Based on Multiples of 25,000 IU Doses Etienne Cavalier, 1 Werner Faché, 2 and Jean-Claude Souberbielle 3 1 Department of Clinical Chemistry, University of Liège, CHU Sart-Tilman, 4000 Liège, Belgium 2 Zuidstationstraat, Gent, Belgium 3 Laboratoire d’Explorations Fonctionnelles, Hôpital Necker-Enfants Malades, 75015 Paris, France Correspondence should be addressed to Etienne Cavalier; etienne.cavalier@chu.ulg.ac.be Received 26 October 2012; Revised 17 December 2012; Accepted 17 December 2012 Academic Editor: Vin Tangpricha Copyright © 2013 Etienne Cavalier et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Vitamin D (VTD) treatment is recommended in patients presenting different causes of diseases. To treat these patients, physicians rely on the different available pharmaceutical forms present in their country. Unfortunately, even in a given country, there is no consensus on the best way to treat the patients. In Belgium, VTD is mostly prescribed as ampoules containing 25,000 IU of VTD. In this randomised controlled study, we evaluated whether four therapeutic schemes using multiples of 25,000 IU of VTD according to basal vitamin D concentration were able to increase or maintain the 25(OH)D serum level above 30ng/mL. We randomized 175 subjects who received the drug (n = 140) or placebo (n = 35). Total duration of the study was 12 weeks. Doses ranged from 4167 to 1667 IU/day. Blood sampling was performed at baseline and each 4 visits. In the treated (placebo) subjects, mean 25(OH)D serum concentration was 18.7 (19.1) ng/mL at baseline and 31.5 (20.7) ng/mL at w-12. At the end of the study, 57.1% of the subjects treated with VTD presented 25(OH)D serum concentration ≥30 ng/mL, whereas 94.3% were ≥20 ng/mL. In conclusion, the doses administered were safe and increased or maintained the 25(OH)D concentration ≥20 ng/mL. However, concentrations ≥30 ng/mL were only achieved in 57.1% of the subjects. 1. Introduction Vitamin D de�ciency has recently been identi�ed as a world- wide problem [1]. Indeed, the dietary sources of vitamin D are scarce, the only really signi�cant ones being marine fatty �sh, although egg yolk and some mushrooms could be additional sources [2]. us, in humans, the major source of vitamin D comes from the exposure of the skin to sunlight. While, in tropical zones, UVB radiation is sufficient throughout the year, it is absent for a signi�cant part of the year in more northern (or southern) latitudes. In Belgium (around 51 ∘ North), the UVB ray will be insufficient to allow the skin synthesis of vitamin D during approximately 6 months of the year. Hence, while all experts agree that the 25-hydroxy vitamin D (25(OH)D) level is the correct indicator of vitamin D status, they do not agree on the 25(OH)D level that should be used to de�ne vitamin D sufficiency. Indeed, the expert panels from the Endocrine Society [3] or the Institute of Medicine (IOM) [4] have recently released divergent recommendations on the use of vitamin D. e recent report by the IOM indicates that a 25(OH)D level of 20 ng/mL is largely sufficient and the RDIs set forth should be sufficient for 97.5% of the population to achieve that level whereas the Endocrine Society group considers that the optimal 25(OH)D level for musculoskeletal health should be 30 ng/mL and more in individual patients. It should be considered that the IOM cutoff is intended for public health recommendations while the Endocrine Society group targets its recommendations on patient care and considers that vitamin D de�ciency (what should be avoided in any patient) corresponds to 25(OH)D levels <20 ng/mL and insufficiency (what may be deleterious for a signi�cant