RESULTS / DISCUSSION Both cross-sectional and longitudinal studies have fairly consistently demonstrated a strong positive correlation between  vitamin D deficiency and subsequent relapse and /or disability in patients with MS .
As well , there appears to be a negative correlation between vitamin D levels and inflammatory markers in MS patients , suggesting that vitamin D modifies serum cytokines to a more anti-inflammatory profile .
However , the criteria of temporality , dose-response , and experimental evidence are yet to be adequately met , although there is preliminary evidence from longitudinal studies and r and omized clinical trials ( RCTs ) of supplementation that vitamin D can attenuate the autoimmune response in patients , and potentially reduce relapse rates and burden of disease .
Ultimately , the current evidence does not permit inference of a causal relationship between vitamin D deficiency and disease activity in MS .
INTRODUCTION Given that vitamin D has a role in immunomodulation , and its levels appear to correlate with the development of Multiple Sclerosis ( MS ) , it is conceivable that vitamin D may also influence disease activity in MS patients .
In this regard , we conducted a systematic review investigating the evidence for : ( 1 ) the role of vitamin D in disease activity in MS , and ( 2 ) the therapeutic supplementation of vitamin D in MS .
A phase I/II dose-escalation trial of vitamin D3 and calcium in multiple sclerosis
Objective : Low vitamin D status has been associated with multiple sclerosis ( MS ) prevalence and risk , but the therapeutic potential of vitamin D in established MS has not been explored . Our aim was to assess the tolerability of high-dose oral vitamin D and its impact on biochemical , immunologic , and clinical outcomes in patients with MS prospect ively . Methods : An open-label r and omized prospect i ve controlled 52-week trial matched patients with MS for demographic and disease characteristics , with r and omization to treatment or control groups . Treatment patients received escalating vitamin D doses up to 40,000 IU/day over 28 weeks to raise serum 25-hydroxyvitamin D [ 25(OH)D ] rapidly and assess tolerability , followed by 10,000 IU/day ( 12 weeks ) , and further downtitrated to 0 IU/day . Calcium ( 1,200 mg/day ) was given throughout the trial . Primary endpoints were mean change in serum calcium at each vitamin D dose and a comparison of serum calcium between groups . Secondary endpoints included 25(OH)D and other biochemical measures , immunologic biomarkers , relapse events , and Exp and ed Disability Status Scale ( EDSS ) score . Results : Forty-nine patients ( 25 treatment , 24 control ) were enrolled [ mean age 40.5 years , EDSS 1.34 , and 25(OH)D 78 nmol/L ] . All calcium-related measures within and between groups were normal . Despite a mean peak 25(OH)D of 413nmol/L , no significant adverse events occurred . Although there may have been confounding variables in clinical outcomes , treatment group patients appeared to have fewer relapse events and a persistent reduction in T-cell proliferation compared to controls . Conclusions : High-dose vitamin D ( ∼10,000 IU/day ) in multiple sclerosis is safe , with evidence of immunomodulatory effects . Classification of evidence : This trial provides Class II evidence that high-dose vitamin D use for 52 weeks in patients with multiple sclerosis does not significantly increase serum calcium levels when compared to patients not on high-dose supplementation . The trial , however , lacked statistical precision and the design requirements to adequately assess changes in clinical disease measures ( relapses and Exp and ed Disability Status Scale scores ) , providing only Class level IV evidence for these outcomes
RESULTS / DISCUSSION Both cross-sectional and longitudinal studies have fairly consistently demonstrated a strong positive correlation between  vitamin D deficiency and subsequent relapse and /or disability in patients with MS .
As well , there appears to be a negative correlation between vitamin D levels and inflammatory markers in MS patients , suggesting that vitamin D modifies serum cytokines to a more anti-inflammatory profile .
However , the criteria of temporality , dose-response , and experimental evidence are yet to be adequately met , although there is preliminary evidence from longitudinal studies and r and omized clinical trials ( RCTs ) of supplementation that vitamin D can attenuate the autoimmune response in patients , and potentially reduce relapse rates and burden of disease .
Ultimately , the current evidence does not permit inference of a causal relationship between vitamin D deficiency and disease activity in MS .
INTRODUCTION Given that vitamin D has a role in immunomodulation , and its levels appear to correlate with the development of Multiple Sclerosis ( MS ) , it is conceivable that vitamin D may also influence disease activity in MS patients .
In this regard , we conducted a systematic review investigating the evidence for : ( 1 ) the role of vitamin D in disease activity in MS , and ( 2 ) the therapeutic supplementation of vitamin D in MS .