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 .
Vitamin D and multiple sclerosis hospital admissions in Scotland.
It is now acknowledged that seasonality is a main feature of the complex neurological disorder multiple sclerosis ( MS ) . Having a spring birthday and being exposed to low levels of sunshine significantly increase the risk of MS later in life.1,2 Although global environment is dominated by seasonality , the observation that vitamin D status is inversely associated with risk of MS later in life and that vitamin D regulates the expression of a large number of MS associated genes , strongly indicate that ultra-violet ( UV ) light exposure and consequent effects on vitamin D production are involved in MS etiology.3,4 Intriguingly this essential hormone appears to also play an important role in influencing MS disease course . Studies have shown an inverse association between 25-hydroxyvitamin D ( 25-OH-D ) levels and clinical MS severity and relapse rate.5 Furthermore , in a recent prospect i ve investigation of a large cohort of MS patients , vitamin D status inversely correlated with relapses over the subsequent 6 months.6 Similar
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 .