Autoimmune diseases remain some of the most difficult of all common conditions to prevent and treat. For these 80 or so disorders — from alopecia causing hair loss to rheumatoid arthritis causing foot pain — there are no known cures.

Fortunately, newer medications can often effectively control symptoms or slow progression.

But wouldn't it be good to understand what might cause them in the first place, as well as what could help prevent them from developing?

According to Cleveland Clinic physicians, some medications, a family history, smoking, exposure to toxins, obesity, and infections may increase your risk. So does being female — 78% of people with an autoimmune condition are.

And it turns out that a vitamin D deficiency may promote autoimmune diseases. One study in the journal Biomolecules highlighted the association of vitamin D deficiency with everything from lupus to Sjogren's syndrome and psoriatic arthritis.

A new study now explains that taking vitamin D supplements can help protect you from developing an autoimmune condition.

The Autoimmune Disease Prevention study found that when women 55 and older and men 50 and older took 2,000 IU of vitamin D daily, they reduced their risk of developing any autoimmune disease by 22%. And taking 1,000 mg of omega-3 fish oil daily reduced the risk by 15%.

We think it's smart to take both.