It seems like every week brings a new study about the benefits of vitamin D: It builds bones, tames psychotic symptoms in bipolar teens, and strengthens the immune system. It is the immune system benefit that attracted the interest of Dr. Benjamin Terrier and colleagues at the Pitié-Salpêtrière Hospital in Paris, France.

The researchers studied 24 people with lupus to determine the possible benefit of vitamin D supplementation on their immune systems. They presented their findings at this year’s annual meeting of the American College of Rheumatology.

So, did it help? Yes, to some extent. The patients received 100,000 IU of vitamin D weekly for 4 weeks, and then the same amount monthly for 6 months. Serum 25(OH)D levels, which had been below normal in all patients at baseline, were normal when measured after 2 months and 6 months.

Most importantly, the number of regulatory T cells increased and the number of T helper lymphocytes decreased after 2 months and also after 6 months of vitamin D supplementation. In addition, antibody-producing memory B cells decreased after 2 months, and activated CD8+ T cells (thought to be associated with lupus in particular) decreased after 6 months.

An added bonus: None of the patients reported adverse events associated with vitamin D, including hypercalcemia or lithiasis.

The findings are preliminary, Dr. Terrier said, and large, randomized controlled trials are needed to confirm the results.

Currently, no one is advocating that lupus patients increase their vitamin D with heavy supplementation, said Dr. Sam Lim of Emory University in Atlanta, Georgia. Dr. Lim served as moderator at the press conference in which the findings were presented.

However, “the study is very important because it is a link to take [the research] to the next step,” Dr. Lim said.

--Heidi Splete (On Twitter @hsplete)

Image courtesy of Mikael Häggström, via Wikimedia Commons