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06 August 2019

Omega-3 and vitamin D – a winning combination!

A new randomised control trial has been published evaluating the effects of the combination of omega-3 and vitamin D supplements on a number of outcomes in pwMS. Studies evaluating a combination of both interventions are scarce, and RCTs are even scarcer.

There are now many thousands of OMSers around the world feeling the benefits of regular omega-3 fatty acids in combination with appropriate-dose vitamin D (plus a few other things like a wholefood, plant-based diet, exercise and meditation!). 

As many of you will know however, this is regrettably not yet standard care for people with MS (pwMS), and one sometimes still hears from our medical advisors “there’s no evidence for that”.  Of course, we at OMS know there is a wealth of evidence, but we continue to strive to build upon this base and promote the highest possible standards of research in lifestyle modification for the management of this condition.

I am pleased to say that we have been greatly assisted in this regard by the work of a team of researchers based in Kashan, Iran.  Published in “The Journal of Nutrition”, they explain the results of a randomised control trial (RCT), evaluating the effects of the combination of omega-3 and vitamin D supplements on a number of outcomes in pwMS.  This is highly significant, as studies evaluating a combination of both interventions are scarce, and RCTs are even scarcer! 

Study methodology

The study was performed over 12 weeks and was double-blinded and placebo controlled. This means that neither the investigators nor the patients in the study knew which intervention they were receiving, with half given the active treatment (omega-3 plus vitamin D), whilst the other half received a placebo (no active drug). This is important, because as a rule, doctors tend to value the results of these types of study much more highly than almost any other, because they remove the potential for bias from both the researchers and patients involved.

60 pwMS were randomly allocated to receive either two omega-3 fatty acid capsules daily (each containing 500mg DHA and 106mg EPA) with vitamin D3 (cholecalciferol 50,000IU fortnightly), or placebos matching in colour, shape, size, packaging, smell and taste. Whether they actually took the treatment was assessed by measuring blood levels of vitamin D, and by participants returning the medication containers.  Each person in the study received a text message daily to remind them to take the supplements. All patients were matched for disease severity based on Expanded Disability Status Scale (EDSS), gender, type of medications, body mass index, and age, ensuring that these factors would not influence the results.

The primary outcome measures of the study were EDSS score and blood markers of inflammation.  Biomarkers of oxidative stress and metabolic profiles were the secondary outcomes.  EDSS scoring was recorded at baseline and at the end of the 12-week intervention, and records of physical activity and diet quality were taken at baseline and weeks 3,6,9 and 12.

53 patients [treatment (n = 26) and placebo (n = 27)] completed the trial.  Overall, most people took their prescribed treatments, with over 90% of capsules consumed in both groups. No side effects were reported in either group.


The results showed that 12 weeks of omega-3 combined with vitamin D significantly decreased the EDSS score between the 2 groups and that common blood markers of inflammation (CRP, TAC, GSH and MDA) all improved significantly in the treatment group compared with the placebo group. In addition, there was a significant reduction in insulin levels (a key hormone in the control of blood glucose levels) and a significant increase in serum HDL cholesterol (commonly known as “good cholesterol”) levels in the treatment group. These are highly beneficial changes in body metabolism.

These findings are extremely important for a number of reasons, not least of which is that this is high quality evidence supporting two of the key recommendations of the OMS program.  It demonstrates that a risk and side-effect free, relatively low-cost treatment makes a significant difference in key outcomes for people with MS (namely disability progression and levels of inflammation).

Of perhaps equal importance are the beneficial effects seen in terms of blood insulin levels and HDL cholesterol.  We know that the more co-mordibities (other health conditions) a pwMS has, the worse the MS tends to be.  This study may suggest that co-administration of omega-3 and vitamin D provides protection against the development of metabolic disease such as type 2 diabetes, and there is already high-quality evidence to show that a better blood lipid profile is associated with lower levels of disability.

Let us all be glad then that we OMSers are ahead of the curve on this one, and continue to enjoy the delicious benefits of flax oil salad dressings and as much vitamin D as the British Summer will afford us – or at least 5,000-10,000IU daily from a packet!

Dr Jonathan White MBChB MRCOG


  1. Ebrahim Kouchaki, Maryam Afarini, Javad Abolhassani, Naghmeh Mirhosseini, Fereshteh Bahmani, Seyed Ali Masoud, Zatollah Asemi, High-dose ω-3 Fatty Acid Plus Vitamin D3 Supplementation Affects Clinical Symptoms and Metabolic Status of Patients with Multiple Sclerosis: A Randomized Controlled Clinical Trial, The Journal of Nutrition, Volume 148, Issue 8, August 2018, Pages 1380–1386,