took a placebo or omega-3 fatty acids alone after slightly more than five years of follow-up, and these effects were more pronounced after two years.
Omega-3 fatty acids alone didn’t significantly lower the incidence of autoimmune disease. Many autoimmune diseases are marked by inflammation, and fish oil is known to help cool inflammation.
Costenbader and colleagues plan to continue to follow participants for a few more years. “We want to see who benefits the most in terms of which autoimmune diseases were prevented and whether vitamin D works as well or better in people who are at high risk for autoimmune disease,” she notes.
This is important as there are more than 80 autoimmune diseases, she explains.
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How to get the appropriate amount of vitamin D
Vitamin D and fish oil are safe, Costenbader shares. “I suggest vitamin D 2,000 IU/day and 1 g/day of marine omega-3 fatty acids (fish oil) — the same doses used in VITAL.”
You can get all of the vitamin D you need by spending 15 minutes in the sun every day. But “this is tricky as a lot of sun exposure leads to skin cancer,” she says.
Still, Costenbader cautions not everyone should jump on the vitamin D supplement bandwagon. “There are some people who need to avoid vitamin D because they have a history of kidney stones or other diseases,” she notes. “Check with your doctor before you start taking supplements.”
VITAL was designed to see if vitamin D could reduce the risk of developing cancer, heart disease and stroke. The risk for developing autoimmune disease was another endpoint in this trial.
“There’s a lot of evidence suggesting that vitamin D would help to reduce the risk for autoimmune disease, and this study confirms that vitamin D status, even if you are vitamin D sufficient, is associated with decreased risk for developing autoimmune diseases,” says Holick.
Dr. Michael Holick has devoted his career to studying vitamin D. He’s a professor of medicine, physiology, biophysics and molecular medicine at Boston University School of Medicine.
This makes sense, he said: “Vitamin D is a major modulator of immune function at every level.”
There’s no downside to increasing your vitamin D intake, and there’s a whole lot of upside, he shares. Studies have linked vitamin D deficiency to a host of diseases and conditions including heart disease, diabetes, the brittle bone disease osteoporosis, certain types of cancer and depression.
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