Vitamin D and Type 2 Diabetes Study (D2d)

Tufts University

Status: Completed

Conditions: Prediabetes; Type 2 Diabetes

Treatments: Dietary Supplement: Vitamin D (Cholecalciferol); Other: Placebo

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT01942694

U01DK098245 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The goal of the Vitamin D and type 2 diabetes (D2d) study is to determine if vitamin D supplementation works to delay the onset of type 2 diabetes in people at risk for the disease and to gain a better understand how vitamin D affects glucose (sugar) metabolism.

Full description

The goal of the Vitamin D and type 2 diabetes (D2d) study is to determine if vitamin D supplementation works to delay the onset of type 2 diabetes in people at risk for the disease and to gain a better understand how vitamin D affects glucose (sugar) metabolism. Researchers at US sites will enroll people with pre-diabetes (people who have higher than normal blood glucose level but not high enough to meet the diagnosis of diabetes). The study will enroll participants over approximately 2 years and participants will be followed for approximately 3 years. Participants will receive either Vitamin D or a placebo by chance. Participants will take 1 pill a day for the duration of the study.

Enrollment: 2,423 patients

Sex: All

Ages: 30+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria:

1. Pre-diabetes ("at increased risk for diabetes") defined by meeting 2-out-of-3 of the following glycemic criteria at the baseline visit:

   1. Fasting plasma glucose (FPG) 100-125 mg/dL
   2. 2-hour plasma glucose (2hPG) 140-199 mg/dL
   3. Hemoglobin A1c (HbA1c) 5.7-6.4%

2. Age ≥ 30 years .(≥25 years for people of the following races: American-Indian, Alaska Native, Native Hawaiian or Other Pacific Islander).

3. Body Mass Index ≥ 24.0 (22.5 for Asians) and ≤ 42.0 kg/m2

4. Provision of signed and dated written informed consent prior to any study procedures.

Major Exclusion Criteria:

1. Diabetes based on either of the following criteria:

   1. History (past 1 year) of hypoglycemic pharmacotherapy (oral or injectable medication approved by the FDA for type 2 diabetes), used for any condition (e.g. pre-diabetes, diabetes, polycystic ovarian syndrome.
   2. Meeting the diagnosis criteria for diabetes

2. History (past 3 years) of hyperparathyroidism, nephrolithiasis or hypercalcemia.

3. Pregnancy (past 1 year by report or positive pregnancy test at screening), intent to become pregnant in the next 4 years or unprotected intercourse. History of gestational diabetes is not an exclusion criterion.

4. Currently breastfeeding.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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2,423 participants in 2 patient groups, including a placebo group

Placebo

Placebo Comparator group

Description:

One pill daily

Treatment:

Other: Placebo

Vitamin D (Cholecalciferol)

Active Comparator group

Description:

One vitamin D pill daily

Treatment:

Dietary Supplement: Vitamin D (Cholecalciferol)