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Completed

NCT Number: NCT01736865

Vitamin D for Established Type 2 Diabetes (DDM2)

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

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Key information

Conditions

Type 2 Diabetes Diabetes Mellitus Diabetes Mellitus, Type 2 Endocrine System Diseases Glucose Metabolism Disorders Metabolic Diseases Nutritional and Metabolic Diseases

Age range

25 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Tufts Medical Center, Boston, Massachusetts, United States

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Cholecalciferol

Drug

Placebo

Drug

Primary outcomes

  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 outcomes

  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 outcomes

  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

Sponsors and collaborators

Lead sponsor

Tufts Medical Center

Other

Collaborators

  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Registry information

Acronym: DDM2

Important dates

Study start
2012
Primary completion
2015
Study completion
2015
First posted
Nov 29, 2012
Registry last updated
Apr 1, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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