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Vitamin D for Established Type 2 Diabetes (DDM2) (DDM2)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01736865
Recruitment Status : Completed
First Posted : November 29, 2012
Results First Posted : January 11, 2019
Last Update Posted : April 1, 2020
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
Tufts Medical Center

Brief Summary:
This research study in adults with established type 2 diabetes will test whether daily vitamin D supplementation affects how the body processes glucose (sugar).

Condition or disease Intervention/treatment Phase
Type 2 Diabetes Drug: Cholecalciferol Drug: Placebo Phase 2 Phase 3

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 127 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Vitamin D for Established Type 2 Diabetes (DDM2)
Study Start Date : December 2012
Actual Primary Completion Date : August 2015
Actual Study Completion Date : August 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D

Arm Intervention/treatment
Placebo Comparator: placebo
One placebo pill daily for 1 year
Drug: Placebo
Active Comparator: cholecalciferol
One cholecalciferol pill daily for 1 year
Drug: Cholecalciferol

Primary Outcome Measures :
  1. Disposition Index [ Time Frame: 6 months ]
    Disposition index by the insulin secretion sensitivity index-2 (ISSI-2). This is an calculated value which represents the ability of a person's pancreatic beta cells to lower blood glucose. A higher number means the pancreas is better able to secrete insulin and improve glucose levels.

Secondary Outcome Measures :
  1. Number of Participants With Change in Glycemia [ Time Frame: 12 months ]
    Change in glycemia (categorical variable, composite outcome) defined as [1] a decrease in diabetes medications or [2] a reduction of equal to or more than 0.4 HbA1c units from baseline without increasing medications.

Other Outcome Measures:
  1. Hemoglobin A1c [ Time Frame: 12 months ]
  2. Change in Diabetes Medications [ Time Frame: 6 and 12 months ]
  3. Variability of Response to Vitamin D Supplementation in Subgroups. [ Time Frame: Baseline and 12 months ]
    Variability of response to vitamin D supplementation in subgroups defined by baseline characteristics: (1) race; (3) 25OHD concentration; (3) diabetes treatment.

  4. Effect of Vitamin D Supplementation on Blood 25-hydroxyvitaminD Concentration [ Time Frame: 12 months ]
  5. Cardiovascular Risk Factors [ Time Frame: 6 and 12 months ]
    Cardiovascular risk factors defined as blood pressure, lipid profile, C-reactive protein and urine albumin excretion

  6. Effect of Vitamin D Supplementation on Plasma Concentrations of Surrogate Biomarkers of Cholesterol Absorption (Campesterol and β-sitosterol) and Endogenous Synthesis (Lathosterol and Desmosterol) [ Time Frame: 6 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   25 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Established type 2 diabetes, defined by one of the following two criteria:
  • Age ≥ 25 years and ≤ 75 years
  • BMI: 23 to 40 kg/m2 inclusive
  • Provision of signed and dated written informed consent prior to any study procedures.

Major Exclusion Criteria

  • "Severe" diabetes defined by one of the following criteria:
  • - (a) Symptoms of hyperglycemia;
  • - (b) Screening HbA1c ≥ 7.5 [may indicate potential for rapid progression during the trial necessitating need to amplify diabetes-specific pharmacotherapy]
  • History of nephrolithiasis or hypercalcemia

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01736865

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United States, Massachusetts
Tufts Medical Center
Boston, Massachusetts, United States, 02111
United States, Ohio
Cincinnati VA Medical Center
Cincinnati, Ohio, United States
Sponsors and Collaborators
Tufts Medical Center
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Tufts Medical Center Identifier: NCT01736865    
Other Study ID Numbers: DK76092-06
R01DK076092 ( U.S. NIH Grant/Contract )
First Posted: November 29, 2012    Key Record Dates
Results First Posted: January 11, 2019
Last Update Posted: April 1, 2020
Last Verified: March 2020
Additional relevant MeSH terms:
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Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Calcium-Regulating Hormones and Agents
Physiological Effects of Drugs
Growth Substances
Bone Density Conservation Agents