Vitamin D in Minorities With Prediabetes

Effect of Vitamin D Supplementation on Pre-Diabetes in a Minority Population

Vitamin D supplementation in minority subjects with both pre-diabetes and low vitamin D levels will delay the development of diabetes.

Study Overview

• Status: Completed
• Conditions: Pre-diabetes
• Intervention / Treatment: Drug: placebo; Drug: vitamin D

Detailed Description

Low vitamin D levels 1) are associated with abnormalities in insulin secretion and insulin action, 2) predict the development of diabetes in those without diabetes, and 3) are more common in people with diabetes. Minority populations (African-Americans and Latinos) are more likely to have both low levels of vitamin D and diabetes. This study will identify minority individuals who are at increased risk for diabetes (those with central obesity, family history of diabetes in first degree relatives and either with hypertension or being treated for hypertension), and determine if they have both pre-diabetes, ie, impaired fasting glucose and/or impaired glucose tolerance, and low levels of vitamin D. Those that have both will be randomized to either high doses of vitamin D or placebo and insulin secretion and action as well as changes in the oral glucose tolerance test (reversion to normal, maintenance of pre-diabetes or development of diabetes) will be monitored at 3 month intervals for one year. This study will test the hypothesis that the increased amount of diabetes in minority populations may be due in part to low levels of vitamin D and whether supplementing this vitamin may delay the development of diabetes.

• Study Type: Interventional
• Enrollment (Actual): 117
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90059
      • Charles Drew University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age greater than 40.
2. Impaired fasting glucose (FPG level greater than 100 and less than 126 mg/dl); and/or
3. Impaired glucose tolerance (2-h plasma glucose concentration after 75 gram glucose load greater than 140 and less than 200 mg/dl)
4. Serum 25-OHD less than 30 ng/ml
5. Able and willing to provide informed consent

Exclusion Criteria:

1. FPG greater than 126 mg/dl or 2-hour-OGTT plasma glucose greater than 200 mg/dl
2. Major psychiatric disorder on medication (excluding successfully treated depression)
3. Diagnosed diabetes mellitus
4. HIV/AIDS
5. Major hematological, hepatic (AST/ALT levels greater than or equal to 2 times normal) or renal eGFR less than 60 ml/min) disorder
6. History of carcinoma, except skin basal cell or squamous cell skin carcinomas
7. Heart failure, unstable angina or history of a myocardial infarction
8. Alcohol or substance abuse
9. Current treatment with glucocorticoids
10. Current treatment with diabetes medications, including metformin
11. Cushing's syndrome
12. Primary hyperparathyroidism
13. Nephrolithiasis
14. Pregnancy or breast-feeding
15. Regular visits to a tanning salon (unlikely in this minority population)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: PREVENTION
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
PLACEBO_COMPARATOR: Placebo; Subjects with low vitamin D levels and pre-diabetes	Drug: placebo; medium chain triglyceride given once per week
EXPERIMENTAL: vitamin D; Subjects with low vitamin D levels and pre-diabetes	Drug: vitamin D; liquid vitamin D3 dissolved in medium chain triglyceride once a week

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent of Subjects Who Develop Diabetes	Diabetes defined by a FPG>=126 mg/dl or a 2-hr glucose concentration on an OGTT of >=200 mg/dl	one year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Disposition Index	Measure of insulin secretion multiplied by measure of insulin sensitivity,both derived from oral glucose tolerance test; higher values are better	Baseline, 3, 6, 9, 12 months

Collaborators and Investigators

• Sponsor: Charles Drew University of Medicine and Science
• Collaborators: American Diabetes Association
• Investigators: Principal Investigator: Mayer B. Davidson, MD, Charles Drew University

Publications and helpful links

General Publications

• Sinha-Hikim I, Duran P, Shen R, Lee M, Friedman TC, Davidson MB. Effect of long term vitamin D supplementation on biomarkers of inflammation in Latino and African-American subjects with pre-diabetes and hypovitaminosis D. Horm Metab Res. 2015 Apr;47(4):280-3. doi: 10.1055/s-0034-1383652. Epub 2014 Jul 10.
• Davidson MB, Duran P, Lee ML, Friedman TC. High-dose vitamin D supplementation in people with prediabetes and hypovitaminosis D. Diabetes Care. 2013 Feb;36(2):260-6. doi: 10.2337/dc12-1204. Epub 2012 Oct 1.

Study record dates

Study Major Dates

• Study Start: March 1, 2009
• Primary Completion (ACTUAL): January 1, 2012
• Study Completion (ACTUAL): June 1, 2012

Study Registration Dates

• First Submitted: April 6, 2009
• First Submitted That Met QC Criteria: April 6, 2009
• First Posted (ESTIMATE): April 7, 2009

Study Record Updates

• Last Update Posted (ESTIMATE): June 14, 2013
• Last Update Submitted That Met QC Criteria: April 17, 2013
• Last Verified: April 1, 2013

More Information

Terms related to this study

• Keywords: diabetes; insulin sensitivity; insulin secretion; oral glucose tolerance test; pre-diabetes; minorities; disposition index
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Hyperglycemia; Prediabetic State; Glucose Intolerance; Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Vitamin D
• Other Study ID Numbers: Vitamin D-Prediabetes; 1-09-CR-15 (OTHER_GRANT: American Diabetes Association)