Loyola University Chicago

Marcella Niehoff School of Nursing

Mary Byrn, PhD, RN

Can Vitamin D3 Improve Cognitive Function in Persons with Type 2 Diabetes? The THINK-D Study

‌Investigator: Mary Byrn, PhD, RN

Accumulating evidence demonstrates that diabetes increases the risk of cognitive dysfunction.  For example, the incidence of dementia is 1.5 to 2.5 higher in persons with diabetes than the general population. These findings have major implications, as there is evidence that cognitive decline significantly impacts the ability to self-manage diabetes. Strategies to prevent cognitive decline in persons with diabetes have not been well studied.  A recent study reported that in persons who had vitamin D deficiency, the risk for all-cause dementia and Alzheimer’s was doubled.  Vitamin D receptors are located in the brain and deficiency of vitamin D has been reported to negatively affect the development of brain. Therefore, providing vitamin D supplementation to improve cognitive function is worthy of study.  A small, randomized controlled trial is underway to determine the effects of vitamin D3 supplementation in persons with type 2 diabetes who have symptoms of cognitive impairment.  Participants are randomized to receive either weekly vitamin D3 supplementation (50,000 IUs) or a matching comparator (5000 IUs) for a period of three months. The study aims are to determine (1) the effect of vitamin D3 supplementation on cognitive function and (2) the effect of vitamin D3 supplementation on diabetes self-management. The importance of this study includes the following:  (1) Vitamin D supplementation is a low cost intervention (2) Vitamin D supplementation has minimal side effects (3) It has potential for high impact for persons with type 2 diabetes who suffer from cognitive impairment which can affect diabetes self-management.