Examination of efficacy, safety and tolerability of vitamin D3 in the treatment of Multiple Sclerosis (MS).

Inclusion Criteria:

• Informed consent
• Age between 18 and 65 at randomization
• Relapsing-remitting MS according to the revised McDonald-Criteria (2005)
• EDSS ≤ 6,0
• Stable immunomodulatory treatment for at least 3 months
• Sufficient birth control (Pearl-Index <1) and negative pregnancy test at screening/randomization

Exclusion Criteria:

• Any other MS-course than RRMS

• Treatment with high dose vitamin D within 6 months prior to randomization

• Patients who have received over the last three months prior to randomization, an immunomodulatory therapy with the exception of IFN-β1b (Betaferon ®)

• Any condition that could interfere with MRI or other study related investigation

• Intolerability to Gd-DTPA

• Hypersensitivity to the drug Colecalciferol

• Patients with sarcoidosis

• Presence or history of nephrolithiasis

• Pseudohypoparathyroidism

• Clinically relevant dysfunction of liver, bone narrow or kidney defined by the following laboratory values:

  • HB <8.5 g / dl
  • WBC <2.5 / nl
  • platelet count <100/nl
  • Creatinine clearance by Cockcroft-Gault formula: Cl <110ml/min (male) and Cl <95ml/min (female)
  • AST / ALT> 3.5 times higher than the upper reference value
  • bilirubin> 2.0 mg / dl
  • hypercalcaemia> 2.7 mmol / l
  • calcium / creatinine ratio in urine> 1

• Treatment with hydrochlorothiazide, digitoxin, digoxin, phenytoin, barbiturates

• Pregnancy or lactation period

• Participation in any clinical study within 3 months before or at any time during study

• Any medical, psychiatric or other condition that could interfere with the patient's ability to understand and give the informed consent, to comply with the protocol or to finish the study any ruling commitment or placement in an institution