Vitamin D as an Immunomodulator: Risks with Deficiencies and Benefits of Supplementation

Vitamin D refers to a class of fat-soluble secosteroids often associated with their role in absorption and metabolism of minerals such as calcium and phosphate. In recent years, our understanding of vitamin D has expanded to include its role in modulating the immune system. Of particular focus are the effects of vitamin D deficiency and supplementation on patients suffering from disorders due to dysregulation of the immune system. In patients with multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease, deficiencies in vitamin D have been associated with an increased risk of disease activity. In this review, we will look at the current state of research in regards to the relationship between vitamin D and immune-dysregulation. We will focus on both the risks associated with vitamin D deficiency as well as the benefits of vitamin D supplementation.