From the Ectrims site:

http://www.akm.ch/ectrims2006/

Longitudinal study of serum 25-hydroxyvitamin D and PTH levels in multiple sclerosis

M. Soilu-Hänninen, M. Laaksonen, I. Laitinen, J.-P. Erälinna, E.-M. Lilius, I. Mononen (Turku, FIN)

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Background: Past sun exposure and vitamin D supplementation have been associated with a reduction in the risk of multiple sclerosis (MS). In an earlier cross-sectional study we showed that newly diagnosed MS patients have lower levels of 25-hydroxyvitamin D (25[OH]D) during MS relapses than in remission. There are no previous longitudinal studies of 25(OH)D levels in MS.

Methods: We measured the serum concentrations of 25(OH)D serially during the first year of the PRISMS study in 23 MS patients and during one year in 23 individually age and sex-matched healthy controls.

In MS patients, the serum 25(OH)D levels were compared with the clinical and MRI disease activity and the therapy received. To compare regulation of 25(OH)D metabolism by parathyroid hormone (PTH) between MS patients and healthy controls, serum levels of intact PTH (iPTH) were determined in these two groups.

Results: 25(OH)D and iPTH levels were similar in MS patients and healthy controls, but 25(OH)D levels were lower and iPTH levels were higher during MS relapses than in remission. All 21 relapses identified during the study occurred at PTH levels above 20 ng/L, whereas 38% of patients in remission had PTH less or equal to 20 ng/L There was no correlation with 25(OH)D or iPTH levels and MRI BOD or T2 activity. Interferon-beta had no effect on the serum levels of 25(OH) D or iPTH.

Conclusion: Vitamin D is a potential regulator of the clinical disease activity in MS. Elevation of intact PTH above 20 ng/L is an indicator of a risk for MS relapse.