New Research have found a possible genetic link between low vitamin D levels and multiple sclerosis.
- Something that has long been suspected, but difficult to prove.
- Scientists are already testing whether giving people extra vitamin D might prevent or ease Multiple Sclerosis.
According to Dr. Brent Richards, associate professor of medicine and human genetics at McGill University, “Our finding is important from a public health perspective because vitamin D insufficiency is common, especially in northern countries like Canada where exposure to sunlight — a common natural source of vitamin D — is decreased through the long winter and where we see disproportionately high rates of Multiple Sclerosis.”
The researchers conducted a genome-wide study using health data on 14,498 people with MS and 24,091 people without the disease. They found that a genetic decrease of the natural use of low vitamin D could be linked to a doubling of the risk for developing MS. After establishing four genetic variants associated with low vitamin D levels.
The researchers wrote that, based on this, increasing vitamin D levels by 1.5 times in a patient should reduce the risk of MS by 50 percent.
Dr. Lisa Melton, MS Research Australia’s Research Development Manager, says the finding is an important link between the observational evidence and the next step, which is testing whether vitamin D supplements can prevent or treat multiple sclerosis.
“It’s looking at people who have had their first episode, first demyelinating event — which is potentially a precursor to multiple sclerosis — and supplementing those people with one of three doses of vitamin D or placebo … to see whether that supplementation can prevent a second relapse or second event,” Melton said.
The cells of the immune system are known to be responsive to vitamin D, while the mechanism by which vitamin D levels influence multiple sclerosis risk is not yet understood.
“We know that vitamin D can modulate the immune system and the evidence show it modulates it in a way that makes the immune system more tolerant, it calms the immune system down, [which] fits with the development of multiple sclerosis,” Melton said.
Multiple sclerosis (MS), also known as disseminated sclerosis or encephalomyelitis disseminata, is a demyelinating disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to communicate, resulting in a wide range of signs and symptoms, including physical, mental, and sometimes psychiatric problems. MS takes several forms, with new symptoms either occurring in isolated attacks (relapsing forms) or building up over time (progressive forms). Between attacks, symptoms may disappear completely; however, permanent neurological problems often occur, especially as the disease advances.
While the cause is not clear, the underlying mechanism is thought to be either destruction by the immune system or failure of themyelin-producing cells. Proposed causes for this include genetics and environmental factors such as infections. MS is usually diagnosed based on the presenting signs and symptoms and the results of supporting medical tests.
There is no known cure for multiple sclerosis. Treatments attempt to improve function after an attack and prevent new attacks. Medications used to treat MS while modestly effective can have adverse effects and be poorly tolerated. Many people pursue alternative treatments, despite a lack of evidence. The long-term outcome is difficult to predict, with good outcomes more often seen in women, those who develop the disease early in life, those with a relapsing course, and those who initially experienced few attacks. Life expectancy is on average 5 to 10 years lower than that of an unaffected population.
Multiple sclerosis is the most common autoimmune disorder affecting the central nervous system. As of 2008, between 2 and 2.5 million people are affected globally with rates varying widely in different regions of the world and among different populations. In 2013, 20,000 people died from MS, up from 12,000 in 1990. The disease usually begins between the ages of 20 and 50 and is twice as common in women as in men. The name multiple sclerosis refers to scars (sclerae—better known as plaques or lesions) in particular in the white matter of the brain and spinal cord. MS was first described in 1868 by Jean-Martin Charcot. A number of new treatments and diagnostic methods are under development.IMAGE/Alamy