Sunshine 2 Study for Women With Diabetes

Phase 2

Completed

Brief Summary: This is a randomized clinical trial (RCT) to determine the effectiveness of vitamin D3 supplementation on depressive symptoms, self-management, and blood pressure in approximately 180 adult women with type 2 diabetes who have significant depressive symptoms. Consenting adult women who are eligible to participate will be randomly assigned to either a weekly dose of 50,000 international units of vitamin D3 supplementation or a matching weekly active comparator of 5,000 international units of vitamin D3 for six months. Participants will complete approximately four in-person study visits and several telephone visits throughout the six month trial period, where the researchers will assess depressive symptoms, diabetes self-management, and systolic blood pressure.

Detailed Description: The primary aim of this study is to determine the effect of vitamin D supplementation on depressive symptoms, self-management, and systolic blood pressure compared to placebo. The hypothesis is that women receiving vitamin D supplementation will report fewer depressive symptoms, increased diabetes self- management mediated by depression improvement, and will have a lower systolic blood pressure compared to those taking placebo at three and six months follow-up.

The secondary aim is to explore the mechanistic effect of vitamin D supplementation on inflammatory biomarkers and their association with depression. Here, the hypothesis is that women receiving vitamin D supplementation will have a decrease in inflammatory biomarkers which will be associated with fewer depressive symptoms compared to those taking placebo at three and six months follow-up.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Current alcohol or substance use disorder
Any unstable or severe psychiatric disease including diagnoses of schizophrenia, bipolar affective disorder, dementia, delirium, or other psychotic disorder
Severe complications of diabetes, such as blindness and/or amputation
Any malabsorption disorder, such as Crohn's disease and/or celiac sprue
Elevated serum calcium level deemed significant by the Principal Investigator
Use of 1,000 or more international units daily vitamin D 60 days before enrollment and unwillingness to discontinue vitamin D supplementation 30 days before enrollment.
Use of St. John's Wort and unwillingness to discontinue St. John's Wort three weeks prior to enrollment.
Participants who are pregnant, nursing, or planning to become pregnant during the study.
Baseline systolic blood pressure (SBP) greater than 160 millimeters of mercury (mmHG) or diastolic blood pressure (DBP) greater than 100 mmHG.
Other serious medical conditions (e.g., cancer, multiple sclerosis, etc.) deemed clinically significant by the Principal Investigator

Arm && Interventions

Group	Intervention	Description
Vitamin D3 comparator	Vitamin D3 comparator	5,000 international units (IUs) of a weekly Vitamin D3 comparator
Vitamin D3	Vitamin D3	50,000 international units (IUs) weekly Vitamin D3

Primary Outcome Measures

Name	Time	Method
Change in Center for Epidemiologic Studies Depression (CES-D) Score From Baseline (Month 0) to Month 6 for the High Dose Cohort Versus Low Dose Cohort	Baseline and 6 months	The Center for Epidemiologic Studies Depression (CES-D) is a self-report questionnaire assessing frequency and severity of depression symptoms. Raw scores range from 0 to 60, where higher scores indicate worse mood. For each participant, her baseline CES-D score is subtracted from her month 6 CES-D score to create a CES-D change score.

Secondary Outcome Measures

Name	Time	Method
Change in Diastolic Blood Pressure From Baseline (Month 0) to Month 6 for the High Dose Cohort Versus Low Dose Cohort	Baseline and 6 months	Diastolic blood pressure is measured in millimeters of mercury (mmHg). For each participant, her baseline diastolic blood pressure is subtracted from her month 6 diastolic blood pressure to create a diastolic blood pressure change score.
Change in Problem Areas in Diabetes (PAIDS) Score From Baseline (Month 0) to Month 6 for the High Dose Cohort Versus Low Dose Cohort	Baseline and 6 months	The Problem Areas in Diabetes (PAIDS) score is a self-report questionnaire that assesses diabetes burden and treatment. Scores range from 0 to 100, where higher scores indicate greater distress. For each participant, her baseline PAID score is subtracted from her month 6 PAID score to create a PAID change score.
Change in Systolic Blood Pressure From Baseline (Month 0) to Month 6 for the High Dose Cohort Versus Low Dose Cohort	Baseline and 6 months	Systolic blood pressure is measured in millimeters of mercury (mmHg). For each participant, her baseline systolic blood pressure is subtracted from her month 6 systolic blood pressure to create a systolic blood pressure change score.