Low Levels of Vitamin D

Vitamin D has anti-inflammatory, anti-infectious, immunomodulatory, and antiproliferative qualities in many autoimmune diseases, including MS.5 Low levels of vitamin D or smoking may potentiate the immunological effects of past EBV infection. It is possible that vitamin D decreases inflammation by favorably influencing the activity of regulatory T lymphocyte cells and restoring a more favorable ratio between the lymphocytes Th2 (protective) and Th1 (aggressive).5

Numerous studies have corroborated the impact of low vitamin D on MS risk. The multinational Environmental Factors in Multiple Sclerosis (EnvIMS) study compared 953 MS patients with maximum disease duration of ten years to 1,717 controls regarding cod liver use (a rich source of vitamin D) during childhood. The researchers found that supplement use during ages 13–18 was associated with reduced risk of MS. They concluded that their findings “not only support the hypothesis relating to low vitamin D as a risk factor for MS, but further point to adolescence as an important susceptibility period for adult-onset MS.”14

Obesity and Poor Diet as Risk Factors

An increasing body of evidence suggests a link between elevated body mass index (BMI) and MS. Obesity is an inflammatory disease, which might be linked either causally or through common pathophysiological pathways with MS.15 A recent study found that women who reported higher BMI in adolescence and young adulthood were younger at MS onset.16 A retrospective five-year study of women with MS examined the relationship between baseline BMI and MS progression, The odds of having increased disability was eight times greater in obese patients than in those with normal BMI (P=.017). The odds of having new brain MRI lesions was 6.2 times greater in overweight subjects (P<.0001) and 2.6 times greater in obese subjects (P=.047) than in non-obese subjects.15