Immunologic Action of a Single Dose Cholecalciferol

Immunologic Functions of a Single Dose of 100.000 I.U. Cholecalciferol (Vitamin D3)

Vitamin D receptors are expressed in activated different immune cells. It is not known, which immune cell type is targeted by exogenous vitamin D. Here, vitamin D-deficient individuals will receive once 100.000 I.U. vitamin D3 either intramuscular or subcutaneous in a double-blind placebo controlled setting. Immune cells will be monitored from the blood over time.

Vitamin D-deficient individuals will receive once

• double-blind, placebo controlled 100.000 I.U.vitamin D3
• intramuscular or subcutaneous

Blood will be taken over time and

• immune cells (T cells, B cells, myeloid antigen presenting cells) are characterized by flow-cytometry
• vitamin D-metabolites will be monitored

Inclusion Criteria:

• informed consent
• 18-60 yrs
• 25-hydroxyvitamin D serum below 50 nmol/L
• women only: effective contraception

Exclusion Criteria:

• 25-hydroxyvitamin D serum above 50 nmol/L
• body-mass index <18 or >30 kg per m2
• planned UV-exposure (UV-index > 5)
• hypersensitivity to vitamin D
• history of hypercalcemia, kidney stones, kidney insufficiency, sarcoidosis, pseudohyperparathyroidism concomitant vitamin A- and/or vitamin D treatment
• treatment with immunosuppressants, immunomodulators, phenytoin, barbiturate, thiazide-diuretics, glycosides
• immobile patients
• out of normal range on screening visit (calcium,phosphate,creatinin,hematology)
• psychiatric hospitalization
• pregnancy / breast-feeding
• dependency / relationship on sponsor
• concomitant participation in other clinical trials (30 days before)
• drug or alcohol abuse
• lack of compliance