The causes of MS include environmental conditions and exposures, immune system factors, possibly viruses, and genetic factors. MS is more common among Caucasians, especially those with connections to Northern Europeans, than among other races, and is very rare in groups such as Eskimos who live at high latitudes. Women are twice as likely to have MS as men.
Cognitive dysfunction occurs in about half of patients with multiple sclerosis (MS). Fortunately, only about 10% of MS patients develop cognitive dysfunction severe enough to significantly impact daily life. Family members of MS patients are usually the first to notice changes in personality or changes in their daily routine. Cognitive dysfunction can range from not being able to find the right word in conversation to impaired reasoning ability. Measuring cognitive dysfunction requires specially trained medical professionals known as neuropsychologists. Neuropsychologists conduct a series of tests to determine the level of cognitive dysfunction present and the strengths still retained by the MS patient.
Studies were conducted at the University of Wisconsin to examine the relationship between vitamin D and MS. Working with the basic research used to study the effects of vitamin D3 on mouse models, it was found that vitamin D3 could "completely prevent experimental autoimmune encephalomyelitis (EAE)." EAE is the widely accepted mouse model of human MS. The working hypothesis was that vitamin D produced in the skin a selective immune system regulator capable of suppressing MS. The theory is supported by anecdotal evidence from Switzerland where a profound difference between MS rates exists between the high-altitude Swiss and the low-altitude coastal Norwegians. The study concluded that early intervention with a protocol of hormonally active vitamin D might prevent genetically susceptible people from developing MS (Hayes et al. 1997).
Research into the use of vitamin B12 has been conducted in Japan and England. In Japan, researchers found that massive doses of vitamin B12 (60 mg a day for 6 months) improved visual and auditory potentials over the treatment period (Kira et al. 1994). The study in England arrived at the conclusion that for those patients below the age of 18, early symptoms were associated with lower vitamin B12 levels, compared to those patients who were older than 18 when MS was first detected (Sandyk et al. 1993).