Endocrine Abstracts

Background: Vitamin D deficiency is a worldwide health issue that affects more than one billion people. Few guidelines assess optimal dosing of vitamin D in general population, and although there is no international consensus, the optimum dosing for vitamin D3 and mainly calcifediol is not known.

Objective(s): To assess the efficacy of calcifediol in the treatment of vitamin D deficiency, compared with therapeutic guidelines recommendations for cholecalciferol in postmenopausal women.

Material and Methods: Phase III–IV, double blind, randomized, controlled, multicentre superiority clinical trial approved by the corresponding Ethics Committees and Health Authorities. Postmenopausal women with baseline levels of 25(OH)D < 20 ng/ml were randomised to calcifediol 266 µg /month for 4 or 12 months (standard and test regime), or to cholecalciferol 25 000 IU/month (as per therapeutic guidelines) for 12 months. Results from an interim analysis - performed upon completion of month 4 visit by 100% of evaluable patients - are presented and reported without unblinding subjects’ study treatments. Both calcifediol groups are summarised for analysis.

Results: 298 women were included in the ITT analysis. All demographic characteristics were balanced amongst groups. Regarding analysis based on World Health Organization classification for BMI (kg/m²), 41.3% were obese, 32.6% were overweight, 25,2% were normal weight and 1% were underweight. Due to limited sample size, underweight group is not considered for analysis. When treatments are compared for BMI groups at Month 4, mean change versus baseline and % subjects achieving 25(OH)D > 30 ng/ml resulted statistically significant (Table 1). When analysing per treatment group,13.5% and 35% of women in the calcifediol group reached 25(OH)D > 30 ng/ml at 1 and 4 months when compared to 0% and 8.2% respectively in the cholecalciferol group (P < 0.001). No relevant safety issues reported for the present analysis.

Conclusions: Calcifediol shows a greater efficacy than cholecalciferol (as recommended in therapeutic guidelines), for the treatment of vitamin D deficiency in postmenopausal women independently of their BMI. A significant percentage of patients on cholecalciferol group failed to reach recommended levels.

Acknowledgements: Osteoferol Study Group principal investigators and their teams: F Cereto, ML Brandi, J del Pino-Montes, JM Quesada-Gómez, MA Colmenero-Camacho, JM Olmos-Martínez, R Alhambra, C Gómez-Alonso, B Galarraga.