Super vitamin: The body’s “D”-fender

Imagine a treatment that could strengthen bones, bolster the immune system, and lower the risk of diseases ranging from heart disease to cancer to Alzheimer’s.

Well, this super therapy might already exist. It’s vitamin D, a nutrient that the body produces from sunlight and that can also be found in dairy products, salmon and fortified foods.

Vitamin D is present in virtually every part of the human body and is essential in bone formation, proper cell growth and calcium processing, as well as a host of other functions. But in this age of sun avoidance and indoor jobs, more and more Americans find themselves lacking in this vital nutrient.

Insufficient levels of vitamin D have been implicated in the development of osteoporosis, certain cancers, heart and neuromuscular disorders, and diabetes. Recent studies even link severely low vitamin D levels to a significant increase in the development of Alzheimer’s disease.

“Many Oklahomans don’t get enough vitamin D,” said Oklahoma Medical Research Foundation researcher Judith James, M.D., Ph.D. “We were surprised, given the amount of sunshine the state gets, that the vitamin D levels were lower than expected in Oklahoma.”

Working with researchers at Stanford University, James and her OMRF colleagues found that low levels of vitamin D also could lead to the production of autoantibodies—proteins that attack the body’s own tissues—in genetically susceptible patients.

In a study of 1,000 volunteers, scientists compared people with the highest levels of vitamin D with those who had the lowest levels.

“We found that healthy volunteers with lower levels of vitamin D still had adequate numbers of immune cells to protect against most infections,” said James, who holds the Lou C. Kerr Endowed Chair in Biomedical Research at OMRF. “But the differences we found could be more serious in patients suffering from autoimmune diseases like lupus, rheumatoid arthritis and multiple sclerosis.”

There is still debate about whether low levels of vitamin D are a direct cause of disease or simply a result of other factors, such as diet or sun avoidance. But, said James, “Vitamin D deficiency is especially troubling in autoimmune disease patients, because it could exacerbate their illness.”

For most people, limited sun exposure and a diet rich in vitamin D-containing foods, like dairy, yogurt, salmon and fortified cereals and juice, can help boost numbers to a healthy level. Supplements can also help allay deficiencies.

“A mounting body of evidence suggests that maintaining proper vitamin D levels is important for good health,” said James. “This seems to hold true not just for people suffering from autoimmune diseases, but for everybody.”

The new OMRF research was published in the journal PLOS ONE. Former University of Oklahoma Health Sciences Center graduate student Lauren Ritterhouse, M.D., Ph.D., who is now a fellow at Boston’s Brigham and Women’s Hospital, and current OUHSC graduate student Rufei Lu contributed to the research.