The Vitamin D-Autoimmune Connection

The Vitamin D-Autoimmune Connection

Julian Whitaker, MD

What do type 1 diabetes, MS, inflammatory bowel disease, and rheumatoid arthritis have in common? These autoimmune disorders tend to be more prevalent in colder climes, and their onset and severity reach a peak in the winter. According to researchers, cold weather isn’t the culprit: lack of sunlight and the resultant drop in vitamin D production are to blame. Two just-published reports provide ample support for this theory.

In an 11-year study of nearly 30,000 women aged 55 to 69, those with the highest intake of vitamin D had a 33 percent lower risk of rheumatoid arthritis than those with the lowest intake. And in a long-term study of over 180,000 female nurses, those who took at least 400 IU of vitamin D per day had a 41 percent lower risk of MS than those who took no vitamin D.

Vitamin D’s protective benefits are attributed to its ability to suppress the activity of immune cells called T lymphocytes. In autoimmune disease, these orchestrators of cell-mediated immunity mistake friend for foe and launch an attack on the body’s own tissues. Vitamin D reins in renegade T cells, preventing or halting this destructive process.


  • Make sure you’re protected by taking at least 1,000 IU of vitamin D per day.

Modified from Health & Healing with permission from Healthy Directions, LLC. Photocopying, reproduction, or quotation strictly prohibited without written permission from the publisher. To subscribe to Health & Healing, click here.

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