Effect of 2 Years of Monthly Calcifediol Administration in Postmenopausal Women with Vitamin D Insufficiency

Background: There are few and controversial results on 24,25(OH)2D and FGF23 acute changes following supplementation with cholecalciferol. Methods: Twenty-seven subjects with 25(OH)D < 30 ng/mL were randomized into three groups to receive a single oral dose of 25,000 I.U. or 600,000 I.U. of cholecalciferol or placebo, respectively. We measured 25(OH)D, 1,25(OH)2D, 24,25(OH)2D, and FGF23 levels at baseline and after 72 h. The 1,25(OH)2D/25(OH)D, 1,25(OH)2D/24,25(OH)2D, and 24,25(OH)2D/25(OH)D ratios were also calculated. Results: There was an increase in 25(OH)D and 1,25 (OH)2D following both doses of cholecalciferol. In the group administered 600,000 I.U., there was a significant increase in the delta changes in 25(OH)D and 1,25(OH)2D compared to the placebo and in the delta 24,25(OH)D2 compared to the placebo and 25,000 I.U. groups (all p < 0.05). A decrease in both the 1,25(OH)2D/25(OH)D and 1,25(OH)2D/24,25(OH)2D ratio (all p < 0.05) was observed in the 600,000 I.U. group. FGF23 values significantly increased only in the group administered 600,000 I.U. Conclusions: 25(OH)D and 1,25(OH)D levels significantly increased following 600,000 IU cholecalciferol administration compared to 25,000 I.U. and placebo. Following the massive administration of cholecalciferol, the CYP24A1 enzyme is actively involved in catabolism, thus, avoiding toxic effects.

Short-Term Effects of Escalating Doses of Cholecalciferol on FGF23 and 24,25(OH)2 Vitamin D Levels: A Preliminary Investigation

Pepe,

Colangelo,

Pilotto

et al. 2024

Efficacy and Safety of Weekly Calcifediol Formulations (75 and 100 µg) in Subjects with Vitamin D Deficiency: A Phase II/III Randomised Trial

Jódar-Gimeno,

Pérez-Castrillón,

Nociar

et al. 2024

Background/Objective: Optimal vitamin D levels are required for bone health and proper functionality of the nervous, musculoskeletal and immune systems. The objective of this study was to assess the efficacy and safety profiles of new weekly calcifediol formulations with the potential to improve adherence and outcome. Methods: A Phase II-III, double-blind, randomized, multicentre trial (EudraCT 2020-001099-14 and NCT04735926). Subjects were randomized 2:2:1 to calcifediol 75 µg, 100 µg and placebo. 25(OH)D levels were measured at 4, 16, 24, 32 and 52 weeks. The main outcome was the percentage of subjects who achieved a response defined as 25(OH)D levels ≥20 ng/mL and/or ≥30 ng/mL at week 16. Results: 398 subjects (51.1 ± 15.96 years, 74.2% females, 98.7% Caucasian) with plasma 25(OH)D levels between 10 and 20 ng/mL were randomized. A total of 376 subjects completed 16 weeks of treatment, and 355 subjects completed the study. Six patients withdrew due to an adverse event, all unrelated to treatment. At week 16, 93.6% and 74.4% of subjects receiving calcifediol 75 µg achieved response levels of ≥20 ng/mL and ≥30 ng/mL, respectively. The calcifediol 100 µg group showed 98.7% and 89.9% of responders for ≥20 ng/mL and ≥30 ng/mL, respectively. Both calcifediol groups showed superiority over placebo at each response level at all time points analyzed (p < 0.0001). Calcifediol treatments increased 25(OH)D levels from baseline to week 24 and remained stable thereafter. The frequency of treatment-emergent adverse events was balanced between groups. Conclusions: New weekly calcifediol 75 and 100 µg formulations showed an effective and sustained response with a good long-term safety profile.

Calcium, Vitamin D, and Aging in Humans

Dominguez,

Gonnelli

2024