.....................They found that for every 10-ng/mL (25nmol/l) increase in 25-hydroxyvitamin D levels, subsequent EDSS (Expanded Disability Status Scale) scores were 0.05 points lower, and subsequent normalized gray matter volume was 7 cc higher
Based on the results and a growing body of literature suggesting a role for vitamin D in MS, lead investigator Dr. Ellen Mowry, an assistant professor of neuroimmunology at Johns Hopkins University, Baltimore, often supplements her patients to a vitamin D level of 40-60 ng/mL =100-150nmol/l, which usually takes 2,000-4,000 international units a day.
People who live north of Baltimore may require more. In the UK it is likely to take more than 5000iu/daily.
CityAssays Birmingham NHS Path lab will send a postal 25(OH)D test for £25 UK or £30 for International. IMO as MS is an inflammatory condition and the highest anti-inflammatory action of vit d is found at 125nmol/l or 50ng/ml Up to 10,000iu daily is safe (it's the amount your skin would create if you were able to live naked outdoors)
BigVits or Amazon UK now offer 5000 iu drops/capsules around £12 for a years supply, Almost as cheap as Iherb/Vitacost or other US discount supplier.