Is Vitamin D a Ray of Hope for Patients With MS?

ATLANTA—Increasing evidence supports an association between vitamin D deficiency and multiple sclerosis (MS), as researchers have found that high supplemental doses of the vitamin are safe and significantly reduced relapse rates in patients with the disease.

Among patients who received a mean of 14,000 IU/day of vitamin D3—which is more than three times the daily amount recommended by the FDA for many adults and included doses as high as 40,000 IU/day—16% had a relapse, compared with 38% of controls who had taken an average of 1,000 IU/day, reported Jodie Burton, MD, a neurologist at St. Michael’s Hospital, University of Toronto, and colleagues at the 23rd Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC).

Potential environmental and genetic causes have been a recent focus of MS research. Studies have shown that a higher incidence of MS occurs in regions where sunlight is not as prevalent and that vitamin D levels and ultraviolet radiation exposure early in life may have an impact on the risk of MS.

“If you are unfortunate enough to live at either pole, you basically don’t have sufficient ultraviolet radiation/sun exposure to produce much vitamin D,” said Dr. Burton. “If you live in North America, you have roughly six months or less of ultraviolet radiation to produce a reasonable amount of vitamin D. Closer to the equator, you have the bulk of the year getting good ultraviolet radiation exposure and the potential for vitamin D sufficiency.”

Vitamin D is produced naturally in the skin when ultraviolet radiation is absorbed and is then converted to 25-hydroxyvitamin D [25(OH)D] and the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D] form. Serum concentration of 25(OH)D is regarded as the most reliable indicator of vitamin D status.

Some investigators have hypothesized that vitamin D may act as an immune modulator in decreasing proliferation of proinflammatory T leukocytes and in decreasing production of various cytokines. “We know MS is predominantly an immune-mediated disease, so presumably vitamin D would have to act on the immune system to be biologically valid,” said Dr. Burton.

If Effective, What Is an Appropriate Dose?

The current recommended daily dose of vitamin D is based on the amount believed to prevent rickets in children, “which is great when you are worried about getting rickets, and which is not so great when you are trying to accomplish something else,” said Dr. Burton. “So if you are looking for compelling evidence that that amount of vitamin D has any impact on the immune system, you are not going to find any.” The FDA recommends 200 IU/day for those up to age 50, 400 IU/day for those 51 to 70, and 600 IU/day for those older than 70. “The amounts are pretty low,” said Dr. Burton.

Dr. Burton and colleagues sought to determine whether vitamin D could have a positive impact on patients already diagnosed with MS and what a safe and effective dose would be. The randomized controlled trial included 25 patients on an escalating dose regimen of vitamin D3 and 24 control subjects who took an average of 1,000 IU/day. The dose of vitamin D was escalated for six months to 40,000 IU/day and then was de-escalated down to zero, for a mean of 14,000 IU/day, with about 70% of the year spent at 10,000 IU/day or higher. All participants also received 1,200 mg/day of calcium throughout the trial.

Calcium was used for two reasons, noted Dr. Burton. “People take calcium regularly, so we wanted to make sure you could add vitamin D to calcium without consequences,” she said. “Second, in studies with the animal model of MS—experimental autoimmune encephalitis—as well as cancer prevention studies, vitamin D and calcium appear to work synergistically.”

The primary outcome measures were those of safety, and included mean change in serum calcium in the treatment group for each dose change and mean difference in serum calcium treatment compared with controls. Secondary outcomes were efficacy related and included changes within and between patient groups for relapse activity, Expanded Disability Status Scale (EDSS) score, and ambulation index. A total of 23 treatment patients completed the trial, along with 22 controls. Patients were seen about every six weeks in the treatment group and at four time points in the control group.

Safety and Efficacy of High-Dose Vitamin D

Dr. Burton and colleagues found that serum calcium levels remained steady and within normal limits throughout the dosing regimen, and there were no significant differences between treated patients and control patients at any time point. Mean urine calcium/creatinine levels in the treatment group were also well within normal, increasing slightly at the higher dosing levels, which is to be expected, according to Dr. Burton.

However, serum 25(OH)D levels increased with high vitamin D doses. At 40,000 IU/day, the mean 25(OH)D level approached 420 nmol/L, “which would scare most people,” said Dr. Burton, adding that 250 nmol/L is the “so-called” normal acceptable level of toxicity. “Despite these values, nobody had any calcium-related consequences whatsoever. So it makes you question exactly how you define toxicity.”

Among clinical outcomes, the treatment group did significantly better, achieving a 41% reduction in annualized relapse rate, compared with a reduction rate of 17% in the control group. “This is with the caveat that this was not blinded, so the result has to be taken with a grain of salt,” commented Dr. Burton.

However, the researchers found a significant change when comparing disability status at time of study entry to disability status at the end of the trial. About 8% of the treatment group left the trial with a greater EDSS score than when they started, versus 37.5% in the control group. “The caveat is that these were small changes in EDSS, so again the clinical interpretation is open to debate, but certainly this was a very robust outcome.”

Regarding immunologic changes, the treatment group compared with the control group, and participants with 25(OH)D levels of 100 nmol/L or greater had a significant drop in their T-cell reactivity and proliferation, a finding not observed in patients who had taken lower doses of vitamin D.

Dr. Burton offered some other reasons as to why patients with MS have low levels of 25(OH)D, including that they may intentionally avoid sun exposure, they do not engage in enough physical activity, and they use steroids. The only adverse event was mild constipation in four treatment patients, and with a change or discontinuation in the calcium supplement, all had resolution of this symptom. One patient had a benign breast calcification on mammography, but the lesion was later found to have been present before the trial.

“We believe that vitamin D3 intake up to 40,000 IU/day for a brief period of time and 10,000q IU/day for a year appears to demonstrate biochemical safety, evidence of clinical benefit, with a grain of salt, and evidence of decreased T-cell proliferation,” Dr. Burton concluded.

Vitamin D Deficiency Linked to MS Severity

In a second trial presented at the 2009 CMSC, researchers found that vitamin D deficiency was associated with a higher disability score and a faster rate of disease progression in patients with MS.

Allison Drake, Neurology-Psychology Research Coordinator, University at Buffalo, State University of New York, and colleagues included 349 patients with MS from the New York State Multiple Sclerosis Consortium in their retrospective study. They used the EDSS to measure disability and the MS Severity Scale (MSSS) to measure the rate of disease progression. Patients also completed a questionnaire regarding clinical and demographic data and provided a blood sample.

A majority of patients were female and Caucasian, the average age was about 50, and most had relapsing-remitting MS. Levels of vitamin D greater than 32 ng/mL were regarded as sufficient, levels between 20 and 32 were insufficient, and levels less than 20 were deficient. About 37% of participants had sufficient levels of vitamin D, 41% had insufficient levels, and 22% had deficient levels.

Due to seasonal changes in exposure to ultraviolet radiation that occur in Buffalo, the researchers examined fluctuations in mean vitamin D levels collected during different seasons and by disease severity. As expected, vitamin D levels were highest during seasons when sun exposure was at its peak, between July and September. On average, less than sufficient levels were detected in all patients during all other seasons. “Interestingly, patients with severe disability, as noted by EDSS scores greater than 6, did not reach sufficient levels at any time during any month,” said Ms. Drake.

In an ordinal regression analysis, after controlling for age, gender, age of disease onset, season, and MS subtype, the researchers found that serum vitamin D levels were significantly predictive of EDSS score. “Patients who were vitamin D deficient were more likely to have high EDSS scores and high disability,” said Ms. Drake. “Also significant were non–relapsing-remitting diagnoses and increasing age. Logistic regression revealed that patients who were vitamin D deficient were 3.3 times more likely to be severely disabled with EDSS scores of greater than 6, compared with patients who had sufficient levels.”

Linear regression analysis also demonstrated that vitamin D levels and MS disease subtype significantly predicted MSSS score. “Though it wasn’t the strongest predictor, decreasing vitamin D levels did make a statistically significant contribution,” said Ms. Drake.

“The results of this study demonstrate that serum vitamin D levels are associated with MS-related disability and disease severity assessed by the EDSS and MSSS,” concluded Ms. Drake. “Patients with deficient vitamin D levels are more likely to have higher EDSS scores, showing more disability, and to have higher MSSS scores, showing more rapid rate of progression. These [findings] can be interpreted in that vitamin D levels in patients with MS may have a potentially protective role if they are sufficient or they may have a detrimental effect if they are deficient.”

—Colby Stong

ATLANTA—Increasing evidence supports an association between vitamin D deficiency and multiple sclerosis (MS), as researchers have found that high supplemental doses of the vitamin are safe and significantly reduced relapse rates in patients with the disease.

Among patients who received a mean of 14,000 IU/day of vitamin D3—which is more than three times the daily amount recommended by the FDA for many adults and included doses as high as 40,000 IU/day—16% had a relapse, compared with 38% of controls who had taken an average of 1,000 IU/day, reported Jodie Burton, MD, a neurologist at St. Michael’s Hospital, University of Toronto, and colleagues at the 23rd Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC).

Potential environmental and genetic causes have been a recent focus of MS research. Studies have shown that a higher incidence of MS occurs in regions where sunlight is not as prevalent and that vitamin D levels and ultraviolet radiation exposure early in life may have an impact on the risk of MS.

“If you are unfortunate enough to live at either pole, you basically don’t have sufficient ultraviolet radiation/sun exposure to produce much vitamin D,” said Dr. Burton. “If you live in North America, you have roughly six months or less of ultraviolet radiation to produce a reasonable amount of vitamin D. Closer to the equator, you have the bulk of the year getting good ultraviolet radiation exposure and the potential for vitamin D sufficiency.”

Vitamin D is produced naturally in the skin when ultraviolet radiation is absorbed and is then converted to 25-hydroxyvitamin D [25(OH)D] and the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D] form. Serum concentration of 25(OH)D is regarded as the most reliable indicator of vitamin D status.

Some investigators have hypothesized that vitamin D may act as an immune modulator in decreasing proliferation of proinflammatory T leukocytes and in decreasing production of various cytokines. “We know MS is predominantly an immune-mediated disease, so presumably vitamin D would have to act on the immune system to be biologically valid,” said Dr. Burton.

If Effective, What Is an Appropriate Dose?

The current recommended daily dose of vitamin D is based on the amount believed to prevent rickets in children, “which is great when you are worried about getting rickets, and which is not so great when you are trying to accomplish something else,” said Dr. Burton. “So if you are looking for compelling evidence that that amount of vitamin D has any impact on the immune system, you are not going to find any.” The FDA recommends 200 IU/day for those up to age 50, 400 IU/day for those 51 to 70, and 600 IU/day for those older than 70. “The amounts are pretty low,” said Dr. Burton.

Dr. Burton and colleagues sought to determine whether vitamin D could have a positive impact on patients already diagnosed with MS and what a safe and effective dose would be. The randomized controlled trial included 25 patients on an escalating dose regimen of vitamin D3 and 24 control subjects who took an average of 1,000 IU/day. The dose of vitamin D was escalated for six months to 40,000 IU/day and then was de-escalated down to zero, for a mean of 14,000 IU/day, with about 70% of the year spent at 10,000 IU/day or higher. All participants also received 1,200 mg/day of calcium throughout the trial.

Calcium was used for two reasons, noted Dr. Burton. “People take calcium regularly, so we wanted to make sure you could add vitamin D to calcium without consequences,” she said. “Second, in studies with the animal model of MS—experimental autoimmune encephalitis—as well as cancer prevention studies, vitamin D and calcium appear to work synergistically.”

The primary outcome measures were those of safety, and included mean change in serum calcium in the treatment group for each dose change and mean difference in serum calcium treatment compared with controls. Secondary outcomes were efficacy related and included changes within and between patient groups for relapse activity, Expanded Disability Status Scale (EDSS) score, and ambulation index. A total of 23 treatment patients completed the trial, along with 22 controls. Patients were seen about every six weeks in the treatment group and at four time points in the control group.

Safety and Efficacy of High-Dose Vitamin D

Dr. Burton and colleagues found that serum calcium levels remained steady and within normal limits throughout the dosing regimen, and there were no significant differences between treated patients and control patients at any time point. Mean urine calcium/creatinine levels in the treatment group were also well within normal, increasing slightly at the higher dosing levels, which is to be expected, according to Dr. Burton.

However, serum 25(OH)D levels increased with high vitamin D doses. At 40,000 IU/day, the mean 25(OH)D level approached 420 nmol/L, “which would scare most people,” said Dr. Burton, adding that 250 nmol/L is the “so-called” normal acceptable level of toxicity. “Despite these values, nobody had any calcium-related consequences whatsoever. So it makes you question exactly how you define toxicity.”

Among clinical outcomes, the treatment group did significantly better, achieving a 41% reduction in annualized relapse rate, compared with a reduction rate of 17% in the control group. “This is with the caveat that this was not blinded, so the result has to be taken with a grain of salt,” commented Dr. Burton.

However, the researchers found a significant change when comparing disability status at time of study entry to disability status at the end of the trial. About 8% of the treatment group left the trial with a greater EDSS score than when they started, versus 37.5% in the control group. “The caveat is that these were small changes in EDSS, so again the clinical interpretation is open to debate, but certainly this was a very robust outcome.”

Regarding immunologic changes, the treatment group compared with the control group, and participants with 25(OH)D levels of 100 nmol/L or greater had a significant drop in their T-cell reactivity and proliferation, a finding not observed in patients who had taken lower doses of vitamin D.

Dr. Burton offered some other reasons as to why patients with MS have low levels of 25(OH)D, including that they may intentionally avoid sun exposure, they do not engage in enough physical activity, and they use steroids. The only adverse event was mild constipation in four treatment patients, and with a change or discontinuation in the calcium supplement, all had resolution of this symptom. One patient had a benign breast calcification on mammography, but the lesion was later found to have been present before the trial.

“We believe that vitamin D3 intake up to 40,000 IU/day for a brief period of time and 10,000q IU/day for a year appears to demonstrate biochemical safety, evidence of clinical benefit, with a grain of salt, and evidence of decreased T-cell proliferation,” Dr. Burton concluded.

Vitamin D Deficiency Linked to MS Severity

In a second trial presented at the 2009 CMSC, researchers found that vitamin D deficiency was associated with a higher disability score and a faster rate of disease progression in patients with MS.

Allison Drake, Neurology-Psychology Research Coordinator, University at Buffalo, State University of New York, and colleagues included 349 patients with MS from the New York State Multiple Sclerosis Consortium in their retrospective study. They used the EDSS to measure disability and the MS Severity Scale (MSSS) to measure the rate of disease progression. Patients also completed a questionnaire regarding clinical and demographic data and provided a blood sample.

A majority of patients were female and Caucasian, the average age was about 50, and most had relapsing-remitting MS. Levels of vitamin D greater than 32 ng/mL were regarded as sufficient, levels between 20 and 32 were insufficient, and levels less than 20 were deficient. About 37% of participants had sufficient levels of vitamin D, 41% had insufficient levels, and 22% had deficient levels.

Due to seasonal changes in exposure to ultraviolet radiation that occur in Buffalo, the researchers examined fluctuations in mean vitamin D levels collected during different seasons and by disease severity. As expected, vitamin D levels were highest during seasons when sun exposure was at its peak, between July and September. On average, less than sufficient levels were detected in all patients during all other seasons. “Interestingly, patients with severe disability, as noted by EDSS scores greater than 6, did not reach sufficient levels at any time during any month,” said Ms. Drake.

In an ordinal regression analysis, after controlling for age, gender, age of disease onset, season, and MS subtype, the researchers found that serum vitamin D levels were significantly predictive of EDSS score. “Patients who were vitamin D deficient were more likely to have high EDSS scores and high disability,” said Ms. Drake. “Also significant were non–relapsing-remitting diagnoses and increasing age. Logistic regression revealed that patients who were vitamin D deficient were 3.3 times more likely to be severely disabled with EDSS scores of greater than 6, compared with patients who had sufficient levels.”

Linear regression analysis also demonstrated that vitamin D levels and MS disease subtype significantly predicted MSSS score. “Though it wasn’t the strongest predictor, decreasing vitamin D levels did make a statistically significant contribution,” said Ms. Drake.

“The results of this study demonstrate that serum vitamin D levels are associated with MS-related disability and disease severity assessed by the EDSS and MSSS,” concluded Ms. Drake. “Patients with deficient vitamin D levels are more likely to have higher EDSS scores, showing more disability, and to have higher MSSS scores, showing more rapid rate of progression. These [findings] can be interpreted in that vitamin D levels in patients with MS may have a potentially protective role if they are sufficient or they may have a detrimental effect if they are deficient.”

—Colby Stong

ATLANTA—Increasing evidence supports an association between vitamin D deficiency and multiple sclerosis (MS), as researchers have found that high supplemental doses of the vitamin are safe and significantly reduced relapse rates in patients with the disease.

Among patients who received a mean of 14,000 IU/day of vitamin D3—which is more than three times the daily amount recommended by the FDA for many adults and included doses as high as 40,000 IU/day—16% had a relapse, compared with 38% of controls who had taken an average of 1,000 IU/day, reported Jodie Burton, MD, a neurologist at St. Michael’s Hospital, University of Toronto, and colleagues at the 23rd Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC).

Potential environmental and genetic causes have been a recent focus of MS research. Studies have shown that a higher incidence of MS occurs in regions where sunlight is not as prevalent and that vitamin D levels and ultraviolet radiation exposure early in life may have an impact on the risk of MS.

“If you are unfortunate enough to live at either pole, you basically don’t have sufficient ultraviolet radiation/sun exposure to produce much vitamin D,” said Dr. Burton. “If you live in North America, you have roughly six months or less of ultraviolet radiation to produce a reasonable amount of vitamin D. Closer to the equator, you have the bulk of the year getting good ultraviolet radiation exposure and the potential for vitamin D sufficiency.”

Vitamin D is produced naturally in the skin when ultraviolet radiation is absorbed and is then converted to 25-hydroxyvitamin D [25(OH)D] and the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D] form. Serum concentration of 25(OH)D is regarded as the most reliable indicator of vitamin D status.

Some investigators have hypothesized that vitamin D may act as an immune modulator in decreasing proliferation of proinflammatory T leukocytes and in decreasing production of various cytokines. “We know MS is predominantly an immune-mediated disease, so presumably vitamin D would have to act on the immune system to be biologically valid,” said Dr. Burton.

If Effective, What Is an Appropriate Dose?

The current recommended daily dose of vitamin D is based on the amount believed to prevent rickets in children, “which is great when you are worried about getting rickets, and which is not so great when you are trying to accomplish something else,” said Dr. Burton. “So if you are looking for compelling evidence that that amount of vitamin D has any impact on the immune system, you are not going to find any.” The FDA recommends 200 IU/day for those up to age 50, 400 IU/day for those 51 to 70, and 600 IU/day for those older than 70. “The amounts are pretty low,” said Dr. Burton.

Dr. Burton and colleagues sought to determine whether vitamin D could have a positive impact on patients already diagnosed with MS and what a safe and effective dose would be. The randomized controlled trial included 25 patients on an escalating dose regimen of vitamin D3 and 24 control subjects who took an average of 1,000 IU/day. The dose of vitamin D was escalated for six months to 40,000 IU/day and then was de-escalated down to zero, for a mean of 14,000 IU/day, with about 70% of the year spent at 10,000 IU/day or higher. All participants also received 1,200 mg/day of calcium throughout the trial.

Calcium was used for two reasons, noted Dr. Burton. “People take calcium regularly, so we wanted to make sure you could add vitamin D to calcium without consequences,” she said. “Second, in studies with the animal model of MS—experimental autoimmune encephalitis—as well as cancer prevention studies, vitamin D and calcium appear to work synergistically.”

The primary outcome measures were those of safety, and included mean change in serum calcium in the treatment group for each dose change and mean difference in serum calcium treatment compared with controls. Secondary outcomes were efficacy related and included changes within and between patient groups for relapse activity, Expanded Disability Status Scale (EDSS) score, and ambulation index. A total of 23 treatment patients completed the trial, along with 22 controls. Patients were seen about every six weeks in the treatment group and at four time points in the control group.

Safety and Efficacy of High-Dose Vitamin D

Dr. Burton and colleagues found that serum calcium levels remained steady and within normal limits throughout the dosing regimen, and there were no significant differences between treated patients and control patients at any time point. Mean urine calcium/creatinine levels in the treatment group were also well within normal, increasing slightly at the higher dosing levels, which is to be expected, according to Dr. Burton.

However, serum 25(OH)D levels increased with high vitamin D doses. At 40,000 IU/day, the mean 25(OH)D level approached 420 nmol/L, “which would scare most people,” said Dr. Burton, adding that 250 nmol/L is the “so-called” normal acceptable level of toxicity. “Despite these values, nobody had any calcium-related consequences whatsoever. So it makes you question exactly how you define toxicity.”

Among clinical outcomes, the treatment group did significantly better, achieving a 41% reduction in annualized relapse rate, compared with a reduction rate of 17% in the control group. “This is with the caveat that this was not blinded, so the result has to be taken with a grain of salt,” commented Dr. Burton.

However, the researchers found a significant change when comparing disability status at time of study entry to disability status at the end of the trial. About 8% of the treatment group left the trial with a greater EDSS score than when they started, versus 37.5% in the control group. “The caveat is that these were small changes in EDSS, so again the clinical interpretation is open to debate, but certainly this was a very robust outcome.”

Regarding immunologic changes, the treatment group compared with the control group, and participants with 25(OH)D levels of 100 nmol/L or greater had a significant drop in their T-cell reactivity and proliferation, a finding not observed in patients who had taken lower doses of vitamin D.

Dr. Burton offered some other reasons as to why patients with MS have low levels of 25(OH)D, including that they may intentionally avoid sun exposure, they do not engage in enough physical activity, and they use steroids. The only adverse event was mild constipation in four treatment patients, and with a change or discontinuation in the calcium supplement, all had resolution of this symptom. One patient had a benign breast calcification on mammography, but the lesion was later found to have been present before the trial.

“We believe that vitamin D3 intake up to 40,000 IU/day for a brief period of time and 10,000q IU/day for a year appears to demonstrate biochemical safety, evidence of clinical benefit, with a grain of salt, and evidence of decreased T-cell proliferation,” Dr. Burton concluded.

Vitamin D Deficiency Linked to MS Severity

In a second trial presented at the 2009 CMSC, researchers found that vitamin D deficiency was associated with a higher disability score and a faster rate of disease progression in patients with MS.

Allison Drake, Neurology-Psychology Research Coordinator, University at Buffalo, State University of New York, and colleagues included 349 patients with MS from the New York State Multiple Sclerosis Consortium in their retrospective study. They used the EDSS to measure disability and the MS Severity Scale (MSSS) to measure the rate of disease progression. Patients also completed a questionnaire regarding clinical and demographic data and provided a blood sample.

A majority of patients were female and Caucasian, the average age was about 50, and most had relapsing-remitting MS. Levels of vitamin D greater than 32 ng/mL were regarded as sufficient, levels between 20 and 32 were insufficient, and levels less than 20 were deficient. About 37% of participants had sufficient levels of vitamin D, 41% had insufficient levels, and 22% had deficient levels.

Due to seasonal changes in exposure to ultraviolet radiation that occur in Buffalo, the researchers examined fluctuations in mean vitamin D levels collected during different seasons and by disease severity. As expected, vitamin D levels were highest during seasons when sun exposure was at its peak, between July and September. On average, less than sufficient levels were detected in all patients during all other seasons. “Interestingly, patients with severe disability, as noted by EDSS scores greater than 6, did not reach sufficient levels at any time during any month,” said Ms. Drake.

In an ordinal regression analysis, after controlling for age, gender, age of disease onset, season, and MS subtype, the researchers found that serum vitamin D levels were significantly predictive of EDSS score. “Patients who were vitamin D deficient were more likely to have high EDSS scores and high disability,” said Ms. Drake. “Also significant were non–relapsing-remitting diagnoses and increasing age. Logistic regression revealed that patients who were vitamin D deficient were 3.3 times more likely to be severely disabled with EDSS scores of greater than 6, compared with patients who had sufficient levels.”

Linear regression analysis also demonstrated that vitamin D levels and MS disease subtype significantly predicted MSSS score. “Though it wasn’t the strongest predictor, decreasing vitamin D levels did make a statistically significant contribution,” said Ms. Drake.

“The results of this study demonstrate that serum vitamin D levels are associated with MS-related disability and disease severity assessed by the EDSS and MSSS,” concluded Ms. Drake. “Patients with deficient vitamin D levels are more likely to have higher EDSS scores, showing more disability, and to have higher MSSS scores, showing more rapid rate of progression. These [findings] can be interpreted in that vitamin D levels in patients with MS may have a potentially protective role if they are sufficient or they may have a detrimental effect if they are deficient.”

—Colby Stong