Winter serum 25-hydroxyvitamin D levels, winter serum parathyroid hormone levels and HLA-DRB1*1501 frequency in multiple sclerosis patients and control subjects
| MS overall | Controls overall | MS Donegal | MS Wexford | MS South Dublin | |
| Mean serum 25(OH) D (nmol/l) | 38.57 | 36.41 | 36.90 | 39.71 | 50.74 |
| Range | 13.30–161.90 | 14.30–97.20 | 13–97 | 15–114 | 13–161 |
| Mean PTH (ng/l) | 41.07 | 42.04 | 42.93 | 39.94 | 38.95 |
| Range | 14.90–321.70 | 5–131.50 | 13–97 | 18–90 | 8–39 |
| % with HLA-DRB1*1501 | 62.90 | 35.20 (p<0.01) | 69 | 63 | 52 |
25(OH)D, 25-hydroxyvitamin D; HLA, human leucocyte antigen; MS, multiple sclerosis; PTH, parathyroid hormone.