Multiple sclerosis and vitamin D

WHAT IS VITAMIN D AND WHY IS IT IMPORTANT IN MS?

Vitamin D is a vitamin that acts like a hormone in the human body. We get vitamin D from sunlight, food, or dietary supplements. The study by Stein et al.¹ examines the relationship of vitamin D and MS. In addition, a recent Patient Page in Neurology® focused on the actions of vitamin D and vitamin D deficiency.² The best level of vitamin D for health is uncertain and may vary depending on the part of the body vitamin D acts on. Many experts believe that blood levels of vitamin D above 30 ng/mL are adequate. (Some studies, such as the present study, use different units of measurement [nmol/L] than are common in the United States. A conversion factor of 2.496 is necessary to switch between these unit systems, and a vitamin D level of 30 ng/mL would be approximately 75 nmol/L in the present study.¹)

Vitamin D appears to act on a number of different systems in the human body. In particular, vitamin D seems to be important for function of the immune system. Therefore, deficiency of vitamin D may play a role in diseases thought to be caused by improper immune responses (autoimmune diseases), including multiple sclerosis (MS). A recent Patient Page in Neurology provided a thoughtful summary of what is known about MS.³

Previous studies have found that low vitamin D levels may increase the risk of developing MS.^4,–,8 A number of studies have also suggested that patients with MS with low levels of vitamin D …