Multiple Sclerosis: Drug, Vitamin D & Diet Evidence and Funding

Table of contents

• Evidence summary
• What multiple sclerosis is
• Symptoms and red flags
• Causes and risk factors
• Diagnosis: the McDonald criteria
• Treatments: what works and what does not
• Medicines in detail
• Supplements, diet and lifestyle claims
• Risks and side effects
• Who to see
• Follow the money: who makes the drugs and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

Independent evidence and credibility scorecard

Independence tiers: 1 = regulator or government body; 2 = academic, charity or Cochrane team with no declared commercial funding for the work; 3 = independent authors analysing mostly manufacturer-run trials, or minor declared industry ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D. Our sources cluster in Europe and the US. Most DMT evidence comes from trials sponsored by a handful of Swiss, German, US and Israeli companies, so the pivotal evidence reflects industry priorities more than patient priorities such as long-term disability.

What multiple sclerosis is

MS affects the brain and spinal cord. The immune system attacks nerve tissue, symptoms come and go as relapses or worsen steadily, and there is no cure (NHS). An estimated 2.9 million people live with MS worldwide (Atlas of MS), and the MS Society reports more than 150,000 in the UK (MS Society). The NHS describes three main courses:

• Relapsing-remitting MS: flare-ups (relapses) followed by recovery. It often becomes secondary progressive over time.
• Secondary progressive MS: symptoms that slowly worsen, usually following relapsing-remitting MS.
• Primary progressive MS: steady worsening from the start, with no remissions. It is less common.

Most people with MS live into old age, though average life expectancy is a few years shorter than in the general population (NHS). The 2024 revision of the diagnostic criteria offers one framework for relapsing and progressive disease at any age (Montalban et al. 2025).

Symptoms and red flags

Common symptoms are fatigue, vision problems, numbness or tingling, dizziness or poor coordination, muscle cramps or stiffness, bladder control problems, memory and concentration problems, and sexual problems (NHS). These have many other causes, so the NHS advises seeing a GP rather than assuming MS.

A relapse, as defined in NICE's guideline, means new symptoms or worsening of old ones lasting more than 24 hours, without infection or another cause, after a stable period of at least a month. NICE says infection (especially urinary and respiratory) must be ruled out first, and that not every relapse needs steroids (NICE NG220, as summarised in search extracts, because the NICE site blocked us from opening the full page).

Causes and risk factors

The cause is unclear. The NHS lists higher risk in people aged 20 to 50, women, people with a close relative with MS, smokers (about twice as likely) and people who have had Epstein-Barr virus (NHS). The strongest single finding is from a US military cohort of more than 10 million young adults: among 955 who developed MS, risk rose 32-fold after Epstein-Barr infection and not after other viruses such as cytomegalovirus (Bjornevik et al. 2022). That study was paid for by the US National Institutes of Health and the Howard Hughes Medical Institute. It shows a strong link, not what to do about it.

Low vitamin D and low sunlight exposure have also been linked to MS risk (PrevANZ abstract). Whether taking vitamin D once MS has begun changes anything is a separate question, covered below.

Diagnosis: the McDonald criteria

There is no single test. A GP refers to a neurologist, who may use examination, blood tests, MRI, lumbar puncture and nerve response tests (NHS). Specialists use the McDonald criteria, which require evidence of damage in different parts of the nervous system (dissemination in space) and at different times (dissemination in time), and no better explanation.

• 2017 revision: spinal fluid bands (oligoclonal bands) can support the diagnosis in people with a typical first episode who already show dissemination in space; symptomatic lesions and cortical lesions can count (Thompson et al., Lancet Neurol 2018).
• 2024 revision: the optic nerve becomes a fifth region; the central vein sign, paramagnetic rim lesions and spinal fluid kappa free light chains can give supportive evidence; certain people with silent MRI findings (radiologically isolated syndrome) can meet criteria; there is guidance for people aged 50 or over and those with other illnesses (Montalban et al. 2025). The panel was convened by ECTRIMS and the National MS Society (Practical Neurology), which are also its listed funders.

Earlier diagnosis helps people start treatment sooner. It also widens the pool of people who may be offered expensive drugs. We could not find independent data on how many people the 2024 changes will newly include.

Treatments: what works and what does not

Medicines in detail

Relapse treatment

Steroids shorten relapses. In COPOUSEP, 199 people with relapsing-remitting MS had 1000 mg of methylprednisolone daily for 3 days, by mouth or by drip, in a double-blind non-inferiority trial. Improvement by day 28 without further treatment was 81% (oral) versus 80% (intravenous), with a difference of 0.5% (90% CI −9.5 to 10.4); insomnia was more frequent with oral treatment (77% versus 64%) (COPOUSEP). The trial was funded by the French Health Ministry, a French MS charity and Teva. A Cochrane review of five small trials (215 people) agreed that oral steroids may be a practical alternative (Burton et al. 2012). NICE's key recommendation is oral methylprednisolone 0.5 g daily for 5 days, with intravenous treatment if oral steroids fail or admission is needed (NICE NG220, from search extracts). These are doses studied or stated by NICE, not instructions.

Interferons and glatiramer acetate

These older injectable drugs reduce relapses by about 16% over 2 years (interferon beta-1a RR 0.84, 95% CI 0.78 to 0.91; glatiramer RR 0.84, 0.76 to 0.93), less than the stronger drugs, and more people stopped glatiramer than placebo because of side effects (OR 1.48), while the interferon estimate was borderline (Cochrane 2024). NICE appraised interferon beta-1a, interferon beta-1b and glatiramer in TA527 (NICE MS product list); we could not open the full recommendation. Glatiramer's maker, Teva, appears in the funding section below.

Natalizumab

In AFFIRM, 942 people had natalizumab or placebo for up to 116 weeks; relapses fell 68% at one year and disability progression fell 42% (HR 0.58, 95% CI 0.43 to 0.77) (AFFIRM, NEJM 2006). Its Europe PMC record lists a Multiple Sclerosis Society grant, while ClinicalTrials.gov names a Biogen employee as study director (registry entry), so we treat it as a manufacturer-linked trial. NICE recommends natalizumab only for rapidly evolving severe relapsing-remitting MS, defined as 2 or more relapses in the previous year plus baseline MRI activity (NICE TA127, wording from search extracts). The key danger is PML, a rare brain infection caused by the JC virus. The EMA says higher-risk people (JC virus antibody positive, treated for more than 2 years, with prior immunosuppressant use or a high antibody index) should continue only if benefits outweigh risks, with more frequent MRI (for example every 3 to 6 months) to be considered (EMA 2016).

Cladribine

CLARITY randomised 1,326 people to cladribine tablets or placebo for 96 weeks. Relapse rates were 0.14 and 0.15 on the two doses versus 0.33 on placebo, and the hazard ratio for 3-month disability progression was 0.67 (95% CI 0.48 to 0.93) at the lower dose. Lymphopenia occurred in 21.6% (lower dose) versus 1.8% on placebo, and herpes zoster in 8 and 12 patients versus none (CLARITY, NEJM 2010). The Europe PMC record has no funding text; four authors were affiliated with Merck Serono, and the drug is marketed by EMD Serono, a Merck KGaA affiliate (BioSpace, EMD Serono release). NICE TA616 recommends cladribine for highly active disease in two defined situations, noting that its effectiveness is not proven but it is likely to beat placebo (NICE TA616, from search extracts). A newer appraisal, TA1053, was published on 15 April 2025; we could not read its outcome.

Ocrelizumab, ofatumumab and rituximab

In OPERA (821 and 835 people), ocrelizumab cut the annualised relapse rate from 0.29 to 0.16 against interferon beta-1a, with infusion reactions in 34.3% (OPERA, funded by Roche). NICE recommended it for active relapsing-remitting MS only if alemtuzumab is unsuitable and the company's discount scheme applies; the list price was £4,790 per 300 mg vial (NICE TA533, from search extracts). For early primary progressive MS, NICE reversed an earlier refusal after a lower, confidential price was agreed with NHS England; the list price was £19,160 per patient per year (NICE statement, May 2019). Ofatumumab was recommended for active relapsing-remitting MS under a simple discount scheme, with NICE noting indirect comparisons suggesting similar effect to ocrelizumab and no direct head-to-head trial (NICE TA699). In ASCLEPIOS (Novartis-funded), the annualised relapse rate was 0.11 versus 0.22 in one trial and 0.10 versus 0.25 in the other against teriflunomide, and serious infections were 2.5% versus 1.8% (ASCLEPIOS). Rituximab has public-trial support, discussed above, and a 2021 Cochrane review identified 5 randomised and 10 non-randomised studies (16,429 people), noting pharmaceutical funding for two of them (Cochrane 2021).

Alemtuzumab

The EMA restricted alemtuzumab (Lemtrada) in November 2019 to adults whose disease stays highly active despite at least one DMT or who have rapidly worsening disease, barred its use in people with certain heart, circulation or bleeding disorders or non-MS autoimmune disorders, and required hospital settings with intensive care access, after reports of serious events including deaths (EMA 2019).

Other options and the stem cell question

NICE has also appraised ponesimod (TA767) and diroximel fumarate (TA794) (NICE MS product list); we could not open their full text. Autologous stem cell transplantation is being tested against alemtuzumab, cladribine, ocrelizumab and ofatumumab in RAM-MS (about 100 people, Norway), StarMS (about 94 people, UK) and BEAT-MS (156 people, US). The UK MS Society reports StarMS results are expected in 2027 (MS Society), and RAM-MS lists primary completion for November 2026 (ClinicalTrials.gov).

Symptom management

The NHS lists medicines for spasms, pain, vision and walking, and non-drug care: fatigue advice, physiotherapy, mobility aids, cognitive behavioural therapy, cognitive rehabilitation, and bladder, bowel and sexual health support (NHS). For cannabis-based spray for spasticity, NICE's cannabis guideline allows a 4-week trial in moderate to severe MS spasticity when other medicines have failed, continuing only if symptoms fall by at least 20% on a 0 to 10 scale (NICE NG144, from search extracts). Search summaries also say NICE does not recommend fampridine for mobility because of cost-effectiveness; we could not confirm this from the page itself. See our guides on sleep and neurological disease, amitriptyline, duloxetine and pregabalin for nerve pain and related symptoms.

Supplements, diet and lifestyle claims

Vitamin D

This is the most heavily promoted supplement in MS, and the evidence is split.

• Cochrane 2018: 12 trials and quasi-trials, 933 people (464 on vitamin D, 469 on comparators). No significant effect on annualised relapse rate, EDSS disability score or new enhancing lesions at 52 weeks, all very low quality. Serious and minor adverse effects did not increase (Cochrane summary; Jagannath et al.).
• SOLAR (Merck KGaA-funded): 229 people on interferon beta-1a took placebo or about 14,007 IU of vitamin D3 a day. No evidence of disease activity at 48 weeks was 36.3% versus 35.3% (OR 0.93, 95% CI 0.53 to 1.63). MRI measures favoured vitamin D but were secondary (SOLAR).
• CHOLINE: 129 randomised, 90 completers. The primary endpoint, annualised relapse rate, was not met (rate ratio 0.80, 95% CI 0.48 to 1.32). We read this through a review and could not verify the trial's own funding (Smolders et al., CNS Drugs 2019).
• PrevANZ (MS Australia-funded): 204 people after a first attack with high-risk MRI took placebo or 1,000, 5,000 or 10,000 IU a day. Conversion to MS by 48 weeks occurred in 58%, with hazard ratios against placebo of 0.87, 1.37 and 1.28 (all with intervals spanning 1). Vitamin D3 was safe (PrevANZ; MS Australia).
• D-Lay MS (French Ministry of Health-funded): 316 people after a first attack took 100,000 IU of vitamin D3 or placebo every 2 weeks for 24 months. Disease activity occurred in 60.3% versus 74.1% (HR 0.66, 95% CI 0.50 to 0.87, P = 0.004). The relapse difference alone was not significant (17.9% versus 21.8%, HR 0.69, P = 0.16). Participants had low baseline vitamin D (median 45 nmol/L, with 22.4% below 30 nmol/L). The authors list limits including exploratory secondary results (D-Lay MS; full text).

What this means: the one positive trial was in people with low vitamin D after a first episode, and the negative trials mostly enrolled people with higher levels or established disease. That is a reasonable idea, not a proven one, and no trial replaced a DMT with vitamin D. Doses above are trial doses, not advice. See our general guide to vitamin D for safety limits and deficiency testing.

Diet

The 2020 Cochrane review of dietary interventions covered 30 trials (11 on polyunsaturated fats, 10 on antioxidants, 3 on whole-diet programmes and 6 on other supplements). Polyunsaturated versus monounsaturated fats showed no difference in relapses (RR 1.02, 95% CI 0.88 to 1.20; very low certainty), and antioxidants versus placebo showed none either (RR 0.98, 0.59 to 1.64; low certainty). The authors concluded there is insufficient evidence for any dietary intervention (Parks et al. 2020). Newer small randomised trials of fasting, ketogenic and anti-inflammatory diets exist, but we could not open them, so we do not grade their results. See also omega-3.

Smoking, exercise and mood

The NHS lists smoking as roughly doubling risk. We did not find a trustworthy source for stopping smoking altering the course once MS has started, so we make no claim. For general support see our guides on exercise and social support for mental health, CBT and mindfulness. NICE's guideline covers fatigue, cognition, mood and sleep within its comprehensive review, with depression and anxiety handled under separate guidelines (NICE NG220, from search extracts).

Risks and side effects

We have not reviewed interactions, vaccination timing or pregnancy planning in this article. These decisions need an MS specialist, and we found no source we could open that addresses them well, so we say nothing further.

Who to see

A GP refers suspected MS to a neurologist (NHS). NICE's guideline expects a comprehensive review of fatigue, cognition, sleep, vision, mood and respiratory function, and a person's DMT choice sits with their MS specialist team. People with a relapse should have it assessed by a clinician with MS expertise before steroids, because infection must be excluded and not every relapse needs treatment (NICE NG220).

Follow the money: who makes the drugs and who funded the evidence

Who makes and sells MS drugs

• Roche (Switzerland): funded the OPERA and ORATORIO trials of ocrelizumab. Roche's January 2026 results named Ocrevus among the top growth drivers of its pharmaceuticals division (Roche, 2025 results). We could not find the exact Ocrevus sales figure.
• Novartis (Switzerland): funded ASCLEPIOS; the paper lists Novartis staff in Basel and East Hanover, New Jersey (ASCLEPIOS).
• Merck KGaA, Darmstadt (Germany), with EMD Serono: funded SOLAR and is linked to cladribine tablets (SOLAR; BioSpace).
• Biogen (US): its Tysabri was the subject of AFFIRM (study director affiliation per ClinicalTrials.gov) and, with Avonex and Tecfidera, of the settlement below.
• Teva (Israel and US): maker of Copaxone (glatiramer) and a co-funder of COPOUSEP.

Prices

In the US, nine DMTs tracked from 1993 to 2013 rose in price at 5 to 7 times the rate of prescription drug inflation. First-generation drugs went from $8,000 to $11,000 to about $60,000 a year; newer drugs commonly launched 25% to 60% above existing ones; and US prices were roughly 2 to 3 times those in the UK, Canada and Australia (Hartung et al. 2015). Natalizumab launched at $25,850 a year in 2004 and fingolimod at $50,775 in 2010 (same paper). In the UK, ocrelizumab's list price was £4,790 a vial, with discounts that NICE and the company keep confidential (NICE TA533). Rituximab, off patent, is the contrast: the Bergen group says its low cost saves the Norwegian health system about NOK 500 million a year, a figure from their own release that we did not verify (Bergen).

Who funded the evidence

Each pivotal trial for a new brand-name drug was paid for by its maker. Publicly or charity-funded trials exist for steroids, rituximab and vitamin D, partly because no company has an incentive to test a cheap or off-patent product. That means independent evidence is thinnest exactly where it would save the most money. The Cochrane analysis rated sponsor influence as high risk in 68% of studies and noted that most agents' effects were measured only to 24 months (Cochrane 2024). A Cochrane group says this same review underpinned the first three MS drugs entering the 2023 WHO Essential Medicines List (Cochrane MS group), which shows how far the public reviews feed policy.

Documented integrity events

• Biogen, September 2022: agreed to pay about $900 million to resolve False Claims Act allegations that from 2009 to March 2014 it paid speaker honoraria, consulting fees and meals to induce prescribing of Avonex, Tysabri and Tecfidera. The settlement resolves allegations only. A former employee brought the case (US Department of Justice; trade summary in Becker's).
• Teva, October 2024: was reported to agree to pay $450 million across two matters, $425 million of it for allegations that donations to two copay charities helped Medicare patients afford Copaxone while its price rose. Teva did not admit wrongdoing (Fierce Pharma; HealthExec). Earlier, the complaint said Copaxone's price went from about $17,000 to more than $73,000 a year (PolicyMed).
• Lemtrada, 2019: EU restrictions after reports of deaths and serious events, described above.

What this means: the claim that MS drugs reduce relapses stands up even with sponsor bias, because regulators, Cochrane and public trials broadly agree. The claims that are hardest to check are long-term disability benefit, comparisons between expensive brands, and real prices. Those depend mostly on company-funded trials and confidential discounts. Vitamin D is an area where the money works the other way: no one sells it as an MS drug, so charities and ministries paid for the trials, and the results disagree.

Related research

For wider, evidence-graded context, see these Pure City Research guides:

• Vitamin D: D2 vs D3, deficiency, benefits and safety
• Sleep and neurological disease
• Stroke: emergency signs and treatment
• Omega-3: fish oil, krill, algal
• Amitriptyline: independent evidence
• Duloxetine: independent evidence
• Pregabalin: independent evidence
• Cognitive behavioural therapy (CBT)
• Mindfulness-based cognitive therapy and MBSR
• Exercise and social support for mental health
• Depression in older adults
• Crohn's disease: another immune-driven condition

Frequently asked questions

Sources and funding notes

What we could not verify: NICE's website blocked automated reading, so NICE statements on NG220, TA533, TA616, TA699, TA127 and NG144 come from search-result extracts, not the full pages. We could not read the full recommendation text of TA527, TA767, TA794 or TA1053. We saw no funding text for the Cochrane DMT, vitamin D, diet, steroid or rituximab reviews, or for the CLARITY and 2017 McDonald records. We could not open the US Department of Justice pages directly (Biogen details are from the search extract and trade coverage). We checked OVERLORD-MS against its PubMed abstract (218 randomised; no new or enlarging T2 lesions in 92.2% on rituximab versus 94.8% on ocrelizumab, risk difference -2.6 points, 95% CI -9.4 to 4.3), but not the full text, and infections were more common on rituximab (82% versus 69%). We did not open the recent diet trials, the original CHOLINE paper, any Roche sales table, or the MS Society prevalence page (it blocked us). We did not check how NICE, EMA or Cochrane are funded. The Teva figures ($450 million in total, $425 million of it for the Copaxone copay matter, no admission of wrongdoing) and the Biogen figure (about $900 million, no admission of liability) were each corroborated by several law-firm and trade reports, but we could not open the Department of Justice releases themselves. We made no claims on pregnancy, vaccines, exercise trials or interaction data.

1. NHS. Multiple sclerosis — patient information; UK National Health Service.
2. NICE NG220. Multiple sclerosis in adults: management — UK guideline; public body (read via search extracts).
3. NICE TA533. Ocrelizumab for relapsing-remitting MS; TA585 (primary progressive); TA699 (ofatumumab); TA616 (cladribine); TA127 (natalizumab); MS product list — NICE technology appraisals; public body; company discounts confidential.
4. NICE. Lower price for MS drug paves the way for positive recommendation (May 2019) — NICE news statement via a government news aggregator.
5. NICE NG144. Cannabis-based medicinal products — UK guideline; public body (search extract).
6. Thompson et al. Diagnosis of MS: 2017 revisions of the McDonald criteria. Lancet Neurol 2018 — expert panel; funding not in record.
7. Montalban et al. Diagnosis of MS: 2024 revisions of the McDonald criteria. Lancet Neurol 2025; Practical Neurology summary — expert panel; National MS Society and ECTRIMS.
8. Gonzalez-Lorenzo et al. Immunomodulators and immunosuppressants for relapsing-remitting MS: a network meta-analysis. Cochrane 2024; Cochrane MS group note — systematic review; funding not in record.
9. Hauser et al. OPERA I and II. NEJM 2017 — pivotal trial; funded by F. Hoffmann-La Roche.
10. Montalban et al. ORATORIO. NEJM 2017 — pivotal trial; funded by F. Hoffmann-La Roche.
11. Hauser et al. ASCLEPIOS I and II. NEJM 2020 — pivotal trial; funded by Novartis.
12. Giovannoni et al. CLARITY. NEJM 2010 — pivotal trial; no funding text in record; authors from Merck Serono.
13. Polman et al. AFFIRM. NEJM 2006; registry entry — pivotal trial; MS Society grant listed; Biogen study director per registry.
14. Svenningsson et al. RIFUND-MS. Lancet Neurol 2022 — public trial; Swedish Research Council.
15. Haukeland University Hospital. OVERLORD-MS in NEJM; HealthDay summary — hospital release and news; public funding (KLINBEFORSK).
16. Cochrane. Rituximab for people with MS (2021) — systematic review; funding not in record.
17. Le Page et al. COPOUSEP. Lancet 2015; Burton et al. Cochrane 2012 — steroid evidence; French Health Ministry, Ligue Française contre la SEP and Teva (COPOUSEP).
18. Jagannath et al. Vitamin D for the management of MS. Cochrane 2018; Cochrane summary — systematic review; funding not in record.
19. Hupperts et al. SOLAR. Neurology 2019 — Merck KGaA-funded trial.
20. Smolders et al. An update on vitamin D and disease activity in MS. CNS Drugs 2019 — review of CHOLINE; no targeted funding.
21. Butzkueven et al. PrevANZ. Brain 2024; MS Australia announcement — MS Australia (charity).
22. D-Lay MS. JAMA 2025; full text — French Ministry of Health grant.
23. Parks et al. Dietary interventions for MS-related outcomes. Cochrane 2020 — systematic review; no grants listed.
24. Bjornevik et al. Epstein-Barr virus and MS. Science 2022 — US NIH (NINDS) and Howard Hughes Medical Institute.
25. EMA. Tysabri and PML (2016); EMA. Lemtrada (2019) — EU regulator.
26. RAM-MS registry; BEAT-MS registry; StarMS registry; MS Society on stem cell trials — trial registries; hospital, government institute (NIAID) and charity.
27. Hartung et al. The cost of MS drugs in the US. Neurology 2015 — price analysis; no targeted funding.
28. US Department of Justice. Biogen settlement (2022); Becker's — government press release (search extract); trade press.
29. Fierce Pharma. Teva settlement (2024); HealthExec; PolicyMed — trade press (search extracts).
30. Roche. 2025 results; BioSpace. EMD Serono CLARITY release — company announcements.
31. MS International Federation. Atlas of MS; MS Society UK — patient federation and charity; donation funded.

Educational research reviewed 6 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.