Can Vitamin D3 Improve Cognitive Function in Individuals With Type 2 Diabetes? (THINK-D)

Summary

Diabetes increases the risk of cognitive dysfunction. The incidence of dementia is 1.5 to 2.5 times higher in persons with diabetes than the general population. There is evidence that cognitive decline significantly impacts the ability to self-manage diabetes. Strategies to prevent cognitive decline in persons with diabetes has 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. The investigators propose a small, randomized controlled trial to determine the effects of vitamin D3 supplementation in persons with type 2 diabetes who have symptoms of cognitive impairment. Persons will be 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. A sample of persons with type 2 diabetes (n=62), who have a subjective complaint of a cognitive dysfunction or scoring at least one standard deviation below normal on a cognitive functioning screening test, have vitamin D levels less 30 ng/ml, are not depressed (as this impacts cognitive function), and do not have severe diabetes complication will be recruited. Participants will be phone screened and complete two baseline visits prior to randomization. They will then have phone call and follow-up visits to assess (1) cognitive function using standardized tests to assess for executive function (2) serum measurements (HBA1c, fasting glucose, vitamin D levels, and cardiometabolic profile) and (3) surveys to assess cognitive function as well as self-management behaviors.

Conditions

• Diabetes
• Executive Dysfunction

Interventions

DRUG

Cholecalciferol

Participants will take randomly assigned high dose cholecalciferol once weekly for three months

DRUG

Cholecalciferol

Participants will take randomly assigned active comparator cholecalciferol once weekly for three months

Sponsors & Collaborators

• University of Chicago

  collaborator OTHER

• Loyola University

  lead OTHER

Principal Investigators

• Mary A Byrn, Ph.D., R.N. · Loyola University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2015-09-23

Primary Completion

2018-07-12

Completion

2018-07-12

FDA Drug

Yes

Countries

• United States

Study Locations