Shining a light on the role of vitamin D in healthy living, disease prevention, and multiple sclerosis

Vitamin D has been a topic of active discussion for decades, and as research continues to uncover the full range of health benefits associated with high levels of vitamin D, bringing awareness to the importance of the sunshine vitamin in disease prevention and everyday health becomes increasingly important.

To mark Vitamin D Awareness Month, the Vitamin D Society has been working hard to spread the word about the implications of vitamin D deficiency and how proper vitamin D levels can dramatically impact our health and quality of life.

Part of their efforts involved hosting a forum for researchers, health care professionals and non-profit organizations to come together and discuss the latest evidence on vitamin D in order to develop a consensus that can be used to educate Canadians on the importance of vitamin D levels for good health. I was fortunate to be at the meeting, which came shortly after World Vitamin D Day on November 2.

The truth is, Canadians simply cannot get sufficient levels of vitamin D from sunshine, due to our geographical location and long winters. Research has repeatedly shown that low levels of vitamin D puts us at a higher risk not only for bone weakness and injury, but also for serious conditions like cancer, cardiovascular disease, diabetes, infection, cognitive impairment, and multiple sclerosis.

Research funded by the MS Society is adding to the growing evidence on the link between vitamin D deficiency and risk of MS. This work was prompted by findings which demonstrated a correlation between increasing latitude (resulting in decreased exposure to sunlight and therefore decreased vitamin D concentrations) and an increase in MS frequency. Some studies suggest that vitamin D deficiency may also affect the clinical course of MS.

One MS Society-funded multi-site Canadian genetics study led by Dr. George Ebers and Dr. Dessa Sadovnick found that vitamin D influences activity levels of a gene strongly linked to MS, via a vitamin D receptor. This was some of the first evidence showing that an environmental risk factor – vitamin D deficiency – and a gene strongly associated with MS are directly associated. The team also discovered that fewer people with MS were born November and more people with MS were born in May, suggesting that maternal vitamin D deficiency during seasons with less sunlight may increase the child’s risk of developing MS. One of the more recent studies I came across on vitamin D in MS came from Dr. Alberto Ascherio and colleagues from Harvard School of Public Health, who reported that higher levels of vitamin D predicted reduced MS disease activity and slower progression in a group of 465 patients receiving interferon treatment.

The data on vitamin D in MS and other diseases is overwhelming, which is why the consensus meeting held last week was invaluable. It brought to light not only the research, but also the issue of vitamin D insufficiency or deficiency in Canada. Here are some highlights from the meeting:

• Vitamin D deficiency may contribute to a range of diseases like MS. We need to focus less on a normal level and more on a healthy level of vitamin D

• Vitamin D is needed for all biological and biochemical functions; can influence expression of genes related to repair, metabolism, inflammation and anti-oxidants

• There is currently no standard definition of an ‘optimal’ level of vitamin D. It is generally agreed that levels of vitamin below 30nmol/L in the blood indicate ‘deficiency’, below 50nmol/L are insufficient and everyone should maintain levels of at least above 50nmol/L.

• Based on the growing body of evidence on vitamin D, scientists recommend a level of between 100-150nmol/L for optimal health and disease prevention.

• According to a recent survey, the average level of vitamin D in Canadians aged 6-69 is 67nmol/L.

• Sunlight is one of the most important sources of vitamin D, however UVB radiation from the sun, which is required to produce vitamin D in the skin, changes substantially with season, latitude and time of day

• We produce little, if any, vitamin D from sun exposure during the winter months, which makes intake from supplements and diet critically important.

• It is impractical to offer a one-size-fits all recommendation for the amount of sun exposure that people need to make sufficient vitamin D levels because this varies according to a number of environmental, physical and personal factors i.e. geographical location, skin pigmentation, use of sunscreen etc.

• Vitamin D can also come from fortified products (milk and juice), oily fish (salmon, trout, sardines), and supplements.

• According to vitamin D expert and MS Society-funded research Dr. Reinhold Veith, most Canadians consume less than half the recommended dietary allowance of vitamin D from diet and supplements combined.

• The current Institute of Medicine and Health Canada recommendation for vitamin D intake to maintain a normal concentration of vitamin D in the blood is 600IU per day for adults and children.

• One study found that 10% of people who follow the recommendation of 600IU per day still fall below healthy blood levels of vitamin D, which has serious implications for public health.

• A Dutch study found that contribution of low vitamin D to mortality is similar to that of smoking, physical inactivity and alcohol consumption.

• Research shows that taking 2,000IU of vitamin D each day from sun exposure and intake of food and supplements is safe.

• Edmonton-based physician Dr. Gerry Schwalfenberg noted that raising vitamin D levels to 105nmol/L in kids up to 16 years old may greatly reduce MS rates in Canada.

• Higher vitamin D levels have been shown to be strongly correlated with improved cognitive performance. Cognitive impairment is seen in over half of people with MS.

• People with MS are at a higher risk of osteoporosis due to steroid use and mobility limitations (especially in women).

• There is some discrepancy in what MS specialists recommend, however many advise patients to take between 2,000–4,000IU vitamin D per day

Although research points to a strong link between low vitamin D levels and poor health, the question of whether vitamin D supplementation can serve as a treatment for certain diseases remains unanswered. Large-scale, well-designed clinical trials for vitamin D can be difficult for a number of reasons, such as the length of time needed to see an effect, or determining how much additional vitamin D participants are getting from sun exposure and diet. For MS, smaller clinical trials have not definitively determined if vitamin D can reduce disease activity, although one recent study has shown a positive effect of vitamin D intake on fatigue.  One promising clinical trial that is currently taking place is the Vitamin D to Ameliorate Multiple Sclerosis (VIDAMS) trial. The study will enlist 172 participants across 16 sites in the U.S. Each participant will take glatiramer acetate for one month followed by either 5,000 IU vitamin D or 600 IU vitamin D daily. Researchers will observe relapses, MRI data, patient reported outcomes, and treatment safety. I am hopeful that the results of this study will address whether taking vitamin D can help to control MS, and help policy makers and health care professionals provide evidence-informed health advice regarding vitamin D for people living with MS.

Categories Research

National vice-president, research, past MS researcher, and PhD in Cellular and Molecular Medicine from University of Ottawa. Leads the MS Society's research program to find the cure for MS and improve the quality of life for people affected by the disease.

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