Researchers determine whether vitamin D can improve mood in women with diabetes

Loyola University Chicago Marcella Niehoff School of Nursing researchers are recruiting women for a study to determine whether raising blood levels of vitamin D can improve mood in women with diabetes. The study also will examine whether raising vitamin D levels can reduce blood pressure and affect how well women manage their diabetes.

Principal investigator Sue M. Penckofer, PhD, RN, and colleagues hypothesize that women who have low levels of vitamin D and receive weekly doses of 50,000 IUs of vitamin D3 will report a better mood than those who receive weekly doses of 5,000 IUs.

"Using a higher dose of vitamin D is potentially an easy and cost-effective way to improve mood," Dr. Penckofer said. "Improving mood may make these women more likely to eat properly, take their medication, get enough exercise and better manage their disease overall."

Penckofer and her Loyola co-investigators received a $1.49 million grant (R01NR013906) for the study from the National Institute of Nursing Research at the National Institutes of Health. Women who are eligible are between the ages of 21 and 75 and have type 2 diabetes, low levels of vitamin D in their blood, are overweight and report symptoms of depression. Women will be randomly assigned to receive one of the two doses for six months. The study began enrolling women in November 2013 and will continue until 2017.

Earlier studies have found that depressed people have elevated levels of inflammatory biomarkers, notably cytokines and C-reactive protein (CRP). The study will explore whether vitamin D supplementation decreases inflammation, thus providing evidence for a plausible mechanism for how the vitamin works as an antidepressant.

About 1 in 10 people in the United States has diabetes, and the incidence is projected to increase to 1 in 4 persons by 2050. Women with type 2 diabetes have worse outcomes than men. The reason may be due to depression, which affects more than 25 percent of women with diabetes. Depression impairs a patient's ability to manage her disease.

Many Americans do not get enough vitamin D, and people with diabetes are prone to vitamin D insufficiency or deficiency. The exact mechanisms behind this are not known, but may include limited intake of foods high in vitamin D, obesity, lack of sun exposure, and genetic variations.