Peripheral Immunological Effects of High-dose Vitamin D Treatment in Healthy Subjects
Status:
Not yet recruiting
Trial end date:
2024-03-01
Target enrollment:
Participant gender:
Summary
Vitamin D deficiency is associated with the risk of developing MS. Vitamin D treatment has
therefore been tested as a background treatment for this pathology, with a seemingly modest
clinical effect. Indeed, the first therapeutic trials using high doses of vitamin D (SOLAR
and CHOLINE) did not show a significant effect on short-term relapses. However, these two
studies showed a significant decrease in the radiological activity of MS on MRI, suggesting a
significant immunomodulatory efficacy but a weak clinical benefit in the short term.
Vitamin D has a pleiotropic effect on the immune system inducing overall immunomodulation.
However, in vivo, only one therapeutic trial has compared the immunological effect of Vitamin
D in healthy subjects and in patients with a first demyelinating episode. Analysis of PBMC by
flow cytometric cell sorting based on a very small number of markers (CD3, CD8, IL-17, IFN-g)
did not find any significant quantitative modulation of Th17 or of their production of IL-10,
IL-17 and IFN-g after treatment with Vitamin D measured by ELISA. However, the evolution of
anti-inflammatory lymphocyte populations has not been evaluated. A few in vitro studies
suggest that the effect of vitamin D may be incomplete on the lymphocytes of MS patients.
The study investigators will use an immunological FACS approach to describe activation
markers and measure the intensity of changes induced in healthy subjects after 3 months of
high-dose cholecalciferol versus placebo treatment using the same protocol as the D-Lay MS
(NCT01817166) study.