Trial · NCT01942694

Vitamin D and Type 2 Diabetes Study

NCT01942694, Not applicable, Completed, Tufts Medical Center; results first posted 2020-09-09

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Vitamin D and Type 2 Diabetes Study. Trials, record NCT01942694. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01942694

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Vitamin D and Type 2 Diabetes Study
NCT number: NCT01942694
Status: Completed
Phases: Not applicable
Enrollment: 2,423 participants, actual
Lead sponsor: Tufts Medical Center
Conditions: Prediabetes, Type 2 Diabetes
Interventions: Vitamin D (Cholecalciferol), Placebo
First posted: 2013-09-16
Last updated: 2022-08-16
Results first posted: 2020-09-09

Source ClinicalTrials.gov

Registered outcomes27

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Time to Development of Diabetes	Approximately 48 months	New-onset diabetes was based on annual glycemic testing of fasting plasma glucose, glycated hemoglobin, and 2-hour post-load plasma glucose and semiannual testing of fasting plasma glucose and glycated hemoglobin. If two or three of the glycemic measures met the 2010 ADA thresholds for diabetes, the participant was considered to have met the diabetes outcome. When only the measure for fasting plasma glucose or glycated hemoglobin met the threshold, confirmatory testing was performed for the positive measure within 8 weeks. If only the measure for 2-hour post-load plasma glucose met the threshold, then a 75-g oral glucose tolerance test to reassess all three glycemic measures was repeated. If the repeat measure was positive or both fasting plasma glucose and glycated hemoglobin were positive (in the case of a repeat oral glucose tolerance test), than the participant was considered to have met the diabetes outcome.
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: 25OHD Concentration	Approximately 48 months
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Approximately 48 months	Race and ethnic group were reporting by the participant. The category "other" includes American Indian or Alaska Native; Native Hawaiian or other Pacific Islander; and other race. Ethnic group includes any race.
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Pre-diabetes Criteria (Two vs. Three Criteria)	Approximately 48 months	Participants met at least two of three glycemic criteria for prediabetes: fasting plasma glucose level, 100 to 125 mg per deciliter (5.6 to 6.9 mmol per liter); plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter (7.8 to 11.0 mmol per liter) (impaired glucose tolerance); and glycated hemoglobin level, 5.7 to 6.4% (39 to 47 mmol per mole).
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: BMI	Approximately 48 months
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Waist Circumference	Approximately 48 months
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Age	Approximately 48 months
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Geographic Location (as a Proxy for Sun Exposure)	Approximately 48 months
Secondary	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Calcium Intake From Supplements	Approximately 48 months
Secondary	Blood Plasma 25OHD Concentration.	Approximately 48 months

1 to 10 of 27Source ClinicalTrials.gov

See all 27 registered outcomes

Outcomes27

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Units	Measured as
PRIMARY	Time to Development of Diabetes	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: 25OHD Concentration	Approximately 48 months
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Pre-diabetes Criteria (Two vs. Three Criteria)	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: BMI	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Waist Circumference	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Age	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Geographic Location (as a Proxy for Sun Exposure)	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Calcium Intake From Supplements	Approximately 48 months	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Blood Plasma 25OHD Concentration.	Approximately 48 months

1 to 10 of 27Source ClinicalTrials.gov

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Results by group38

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Units
Time to Development of Diabetes	Placebo		323	Participants
Time to Development of Diabetes	Vitamin D (Cholecalciferol)		293	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Placebo	Race: White	806	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Vitamin D (Cholecalciferol)	Race: White	810	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Placebo	Race: Black	315	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Vitamin D (Cholecalciferol)	Race: Black	301	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Placebo	Race: Other	91	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Vitamin D (Cholecalciferol)	Race: Other	100	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Placebo	Ethnic Group: Hispanic	105	Participants
Variability of Response to Vitamin D Supplementation by Baseline Characteristic: Race (as a Proxy for Skin Pigmentation)	Vitamin D (Cholecalciferol)	Ethnic Group: Hispanic	120	Participants

1 to 10 of 38Source ClinicalTrials.gov

See all 38 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Placebo	1,212
Overall Study	STARTED	Vitamin D (Cholecalciferol)	1,211
Overall Study	COMPLETED	Placebo	1,211
Overall Study	COMPLETED	Vitamin D (Cholecalciferol)	1,211
Overall Study	NOT COMPLETED	Placebo	1
Overall Study	NOT COMPLETED	Vitamin D (Cholecalciferol)	0

Source ClinicalTrials.gov

Adverse events12

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Hypercalcemia	Endocrine disorders	Placebo	3	1,212	3
other	Hypercalcemia	Endocrine disorders	Vitamin D (Cholecalciferol)	5	1,211	5
other	Fasting urine calcium: creatinine ratio >0.375	Endocrine disorders	Placebo	1	1,212	1
other	Fasting urine calcium: creatinine ratio >0.375	Endocrine disorders	Vitamin D (Cholecalciferol)	1	1,211	1
other	Low estimated glomerular filtration rate	Endocrine disorders	Placebo	2	1,212	2
other	Low estimated glomerular filtration rate	Endocrine disorders	Vitamin D (Cholecalciferol)	1	1,211	1
other	Nephrolithiasis	Endocrine disorders	Placebo	20	1,212	21
other	Nephrolithiasis	Endocrine disorders	Vitamin D (Cholecalciferol)	24	1,211	25
serious	Death	Cardiac disorders	Placebo	5	1,212
serious	Death	Cardiac disorders	Vitamin D (Cholecalciferol)	5	1,211

1 to 10 of 12Source ClinicalTrials.gov

See all 12 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Placebo	5	1,212
Total, all-cause mortality	Vitamin D (Cholecalciferol)	5	1,211
Total, other adverse events	Placebo	26	1,212
Total, other adverse events	Vitamin D (Cholecalciferol)	31	1,211
Total, serious adverse events	Placebo	153	1,212
Total, serious adverse events	Vitamin D (Cholecalciferol)	173	1,211

Source ClinicalTrials.gov

Papers11

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
25205139	DERIVED	PubMed
27899488	DERIVED	PubMed
29941495	DERIVED	PubMed
31007049	DERIVED	PubMed
31173679	DERIVED	PubMed
31965161	DERIVED	PubMed
33693713	DERIVED	PubMed
35140313	DERIVED	PubMed
35753926	DERIVED	PubMed
37001590	DERIVED	PubMed

1 to 10 of 11

See all 11 papers

Grants1

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

Project	Title	Principal investigators	Organization	Funder	Fiscal years
U01DK098245	Vitamin D and Type 2 Diabetes (D2d)	PITTAS, ANASTASSIOS G	TUFTS MEDICAL CENTER	NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES	2013 to 2020

Source NIH RePORTER

Trial comparisons3

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
Vitamin D (Cholecalciferol) vs Placebo: deaths from any cause	Trial comparisons
Vitamin D (Cholecalciferol) vs Placebo: Time to Development of Diabetes	Trial comparisons
Vitamin D (Cholecalciferol) vs Placebo: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT01942694

GET https://conductscience.org/api/trials/v1/NCT01942694/registered?page=2

API reference For AI assistants