Cape Town - Research has linked vitamin D deficiency with a debilitating neurological condition – multiple sclerosis (MS) – showing, for the first time, that a decrease in the sunshine vitamin may increase the risk of the disease.
The Australian Broadcasting Corporation reports that the researchers found a possible genetic link between low vitamin D levels and multiple sclerosis.
The study, published in PLoS Medicine shows individuals carrying certain genetic traits that predispose them to having lower vitamin D also have a higher risk of multiple sclerosis; a chronic disease in which the immune system attacks the nervous system.
There has been a long-standing hypothesis that low vitamin D and multiple sclerosis are linked.
However these studies don't necessarily show that low vitamin D causes multiple sclerosis; at best, they merely suggest an association that could actually be caused by other factors, says co-author Dr. Brent Richards, associate professor at McGill University in Montreal.
ABC reports that in the current research, the team used data from an earlier study of nearly 34 000 people that looked for genetic markers of low vitamin D, and singled out four genetic variants strongly linked with low vitamin D levels.
Then in another group of nearly 14 500 people with MS and 24 000 controls, they looked at the association between these four genetic markers and the risk of multiple sclerosis.
They found that individuals with any one of these genetic markers, and who were therefore vitamin D deficient, were much more likely to have multiple sclerosis.
MS is an incapacitating neurological and auto-immune disorder that affects the nerves in the brain and spinal cord.
During the disorder, an abnormal immune-mediated response attacks the myelin or the fatty tissue that forms an insulating sheath around nerve fibres. The damage caused by scarring of myelin then slows down or blocks the transmission of electrical signals along the nerves to and from the brain – causing symptoms such as loss of vision, muscle stiffness, fatigue and balance problems.
* Another disease linked to vitamin D deficiency is tuberculosis. In recent years, UCT researchers have suggested that other than the HIV factor, insufficient vitamin D increased the risk of TB in black people, both in the UK and Cape Town. Prolonged Cape Town winters were blamed for the lack of the “sunshine” vitamin, which is acquired by the body through exposure to the sun.
Cape Argus, IOL