Efficacy and Safety of Calcifediol vs Placebo in Subjects With Vitamin D Deficiency

• Calcifediol 75mcg (Drug): Soft gelatin capsule. Oral administration once per week
• Calcifediol 100mcg (Drug): Soft gelatin capsule. Oral administration once per week
• Calcifediol 125mcg (Drug): Soft gelatin capsule. Oral administration once per week.
• Placebo (Other): Soft gelatin capsule. Oral administration once per week.
• Placebo (Other): Soft gelatin capsule. Oral administration once per week.

Primary outcomes

• To assess efficacy for each cohort in terms of percentage of subjects achieving 25-OH-D levels ≥ 30 ng/mL and/or ≥ 20 ng/mL at 16 weeks of treatment. [16 weeks]: Percentage of subjects who achieve 25-OH-D levels ≥ 30 ng/mL and/or ≥ 20 ng/mL

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Male or female subjects ≥ 18 years of age.
* Evidence of serum 25-OH-D levels < 20 ng/mL or ≤ 10 ng/mL, for each cohort.
* Written informed consent.
* For females of childbearing potential only: willing to perform pregnancy tests, must agree to use highly effective methods of birth control throughout the study.

Exclusion Criteria:

* Subjects receiving any treatment with calcifediol, vitamin D analogues, vitamin complexes or vitamin D supplements.
* Subjects taking drugs that could modify vitamin D levels.
* Subjects taking calcium supplements.
* Uncorrected hypercalcaemia, known hypercalciuria or nephrolithiasis.
* Severe renal impairment.
* Subjects diagnosed with liver or biliary failure, congestive heart failure, malabsorption, primary hyperparathyroidism, hypothyroidism, prolonged immobilisation, sarcoidosis, tuberculosis or other granulomatous diseases or hyperthyroidism.
* Any present or previous malignancy.
* Known contraindications or sensitivities to the use of the IP or any of its components.
* Pregnant woman, breastfeeding woman or woman planning a pregnancy.
* Subject has received an IP within 30 days before the start of the screening or is currently enrolled in an investigational interventional study.
* Any condition that may jeopardise the clinical trial conduct according to the protocol.
* Employees of the investigator or clinical trial site, as well as family members of the employees or the principal investigator.
* Person committed to an institution by virtue of an order issued either by judicial or other authorities.