Data from a large placebo-controlled clinical trial investigating the effects of daily vitamin D and omega-3 use indicates the supplements may reduce the risk of developing autoimmune disease.
At the five-year follow-up, the trial found those taking vitamin D alone, or in conjunction with omega-3, showed lower rates of autoimmune disease compared to those taking placebo.
Called VITAL, the ongoing trial has enrolled more than 25,000 participants who were randomly assigned to one of four groups: vitamin D and omega 3, vitamin D plus placebo, omega-3 plus placebo, or double placebo.
Autoimmune diseases in the trial included rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, psoriasis, and inflammatory bowel disease.
Overall, after five years, those taking either vitamin D alone or vitamin D alongside omega-3 displayed significantly lower rates of autoimmune disease compared to those in the placebo group.
Little difference was seen in rates of autoimmune disease between the placebo group and those taking omega-3 alone, suggesting the benefits detected were primarily due to vitamin D supplementation.
Another important finding was the longer the trial went on, the lower the risk for autoimmune disease in the vitamin D group. Looking at the data from just the last three years of the trial saw 39 percent fewer cases of autoimmune disease in the vitamin D group compared to placebo.
Costenbader is relatively comfortable recommending the vitamin D/omega-3 combination to those over the age of 50 looking for ways to reduce their risk of autoimmune disease.
“Now, when my patients, colleagues, or friends ask me which vitamins or supplements I’d recommend they take to reduce risk of autoimmune disease, I have new evidence-based recommendations for women age 55 years and older and men 50 years and older,” noted Costenbader.
Another recently published study looking at vitamin D and overall mortality tracked more than 20,000 people taking either vitamin D or a placebo for several years.