Weekly calcifediol 100 µg raises vitamin D levels in women in phase II/III trial

A post hoc analysis of a randomised, double-blind, placebo-controlled phase II/III clinical trial published in the journal Nutrients demonstrated the long-term efficacy and safety of weekly calcifediol at a dose of 100 µg in women with vitamin D deficiency. The cohort included 261 female participants, with 192 assigned to the active intervention group and 69 to the placebo cohort mdpi.comNutrientsmdpi.comOpen source ↗.

Efficacy dynamics and target concentrations

Weekly administration of 100 µg calcifediol achieved superior efficacy compared to placebo starting at week 4. At this time point, 68.2% of participants in the calcifediol group achieved serum 25-hydroxyvitamin D concentrations of 20 ng/mL or higher, compared to 5.8% in the placebo group. Furthermore, 21.4% of patients receiving calcifediol reached at least 30 ng/mL, whereas no patients in the placebo group met this threshold. Consistently higher proportions of participants achieving target concentrations were maintained through week 52.

Long-term stability and subgroup parameters

The mean serum 25(OH)D concentration in the calcifediol arm rose from a baseline value of 12.21 ng/mL to 39.47 ng/mL by week 16. Over the remainder of the 12-month study, mean concentrations remained stable within the range of 41 to 43 ng/mL. Exploratory evaluations showed that outcomes did not differ significantly across body mass index categories or menopausal status groups. The reported safety profile of weekly calcifediol was comparable to placebo, showing no evidence of toxicity.