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CompletedNCT01741181DIMENSIONUpdated Nov 18, 2014

Vitamin D Supplementation in Patients With Diabetes Mellitus Type 2

A Phase 4 interventional study of Vitamin D supplementation and Placebo Pill in Diabetes Mellitus Type 2 and Vitamin D Deficiency, sponsored by Tan Tock Seng Hospital. Completed at 1 site in Singapore. Open to participants aged 21 Years to 80 Years. Per ClinicalTrials.gov, last updated 2014-11-18.

Sponsored by Tan Tock Seng Hospital · Phase 4, Interventional, and Prevention

Phase
Phase 4
Study type
Interventional
Enrollment
64
Allocation
Randomized
Ages
21 Years to 80 Years
Sex
All
01

Study summary

Background and Objectives :

The presence of vitamin D deficiency in patients with type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD). We aim to see whether supplementation of vitamin D in these patients helps to improve the endothelial function (EF) a surrogate marker of CVD risk.

Hypothesis: Vitamin D supplementation in patients with T2DM and low serum 25(OH) D concentrations (\<30ng/ml) will improve EF as measured by the Endo-PAT machine by 0.4 units (30% improvement over baseline) and/or will result in a increase of EPCs (CD133+/KDR+) and CD45dim CD34+/KDR.

The investigators will test this hypothesis by comparing 2 groups of T2DM patients randomized to placebo or vitamin D3 for 16 weeks.

Methods:

This is a 16 weeks trial in which 120 T2DM patients will be screened with the aim to recruit 60 T2DM patients with vitamin D deficiency or insufficiency. Out of these 60 patients , 30 patients will be started on vitamin D supplementation and 30 patients will be given a matched placebo. Endothelial function (EF) will be checked before and after supplementation to see a change in EF.

Significance of Project:

If this study shows a significant improvement of EF, it would justify larger scale studies to show that vitamin D supplementation in patients with T2DM mitigates CVD risk and vitamin D supplementation in patients with T2DM and vitamin D deficiency to improve CVD risk.

Read the detailed description

Overall Aims: Type 2 Diabetes Mellitus (T2DM) is increasingly more prevalent in Singapore and is a high cardiovascular diseases (CVD) risk factor (1,2). The presence of low serum 25(OH)D concentrations (\<30ng/ml) has also been classified as an independent predictor of CVD(3,4) and has been seen to be more prevalent in T2DM (5-7). We aim to see whether replacement with vitamin D in these patients helps to mitigate CVD risk. Since endothelial dysfunction is one of the earliest manifestations of CVD and is a very robust surrogate marker, we aim to measure the endothelial function (EF) before and after vitamin D supplementation to evaluate for beneficial impact on this endpoint.

Specific Aims: Although, there are some small scale studies done with a single high dose replacement of vitamin D2/D3, no studies have been done using regular daily supplementation with vitamin D3 and with measurement of EF using the Endo-PAT machine or measurement of endothelial progenitor cells (EPCs).We are doing this pilot study to see whether replacement with vitamin D results in an improvement of EF as measured using the Endo-PAT and estimation of EPCs and some biomarkers as independent established surrogate markers of CVD risk. The estimation of endothelial progenitor cells has been proposed as a surrogate marker of vascular dysfunction and is known to be reduced in patients with cardiovascular risk factors (8). The no. of circulating endothelial cells (CECs) and endothelial microparticles have been seen to be elevated in patients with cardiovascular risk factors and DM and has also been proposed as a effective surrogate marker. We aim to quantify the no. of endothelial progenitor cells (EPCs) staining positive for CD133+/KDR (kinase insert domain-containing receptor),CD34+/KDR and CD45dim CD34+/KDR , CECs (CD 146+/CD45- ) and EMPs derived from endothelial progenitors (CD45-/CD146+/CD34+/CD117+) and from mature endothelial cells (CD45-/CD146+/CD34+/CD117-).using flow cytometry.

Primary Hypothesis:

Vitamin D supplementation in patients with T2DM and low serum 25(OH) D concentrations (\<30ng/ml) will improve EF as measured by the Endo-PAT machine by 0.4 units (30% improvement over baseline) and/or will result in a increase of EPCs (CD133+/KDR+) and CD45dim CD34+/KDR. The investigators will test this hypothesis by comparing 2 groups of T2DM patients randomized to placebo or vitamin D3 for 16 weeks.

Secondary Objectives:

To explore the prevalence of low serum 25(OH) D concentrations (\<30ng/ml) in T2DM patients and evaluate the difference in the EF in the two groups. To see whether vitamin D supplementation helps to further improve other parameters such as biomarkers, blood pressure, BMI, urine albumin-to-creatinine ratio (ACR), lipid profile of T2DM patients.

02

Conditions studied

  • Diabetes Mellitus Type 2
  • Vitamin D Deficiency

Keywords

  • 25(OH)Vitamin D
  • Diabetes mellitus
  • Endothelial Function
03

In context

Diabetes Mellitus

10,925 studies on the registry are indexed under Diabetes Mellitus; 1,319 are open to participants now.

This study's enrollment of 64 is below the median of 80 across 8,367 interventional studies indexed under Diabetes Mellitus.

Browse Diabetes Mellitus studies →

Lead sponsor

Tan Tock Seng Hospital is the lead sponsor of 103 studies on the registry; 17 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
21 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Subjects with Type 2 Diabetes Mellitus
  • HbA1c : 6.0-10.0%
  • Male of female aged 21-80 years
  • Stable Diabetes, blood pressure and hyperlipidemia medications (a 25% dose adjustment is allowed) in the last three months
  • Baseline serum 25(0H)D concentration \<30ng/ml for randomisation

Exclusion criteria

Exclusion Criteria:

  • Baseline serum 25(OH)D concentration >30ng/ml
  • Baseline HbA1c>10.1%
  • Baseline hypercalcemia (Ca>2.58 mmol/L)
  • Known case of Primary Hyperparathyroidism
  • Known to be on bisphosphonates
  • Known to be on Vitamin D supplementation of 1000 units daily or more in the last one year.
  • Chronic renal failure with eGFR\<30ml/min
  • Known to have cirrhosis of the liver or transaminitis with ALT/AST >3X ULN
  • Patients with h/o sarcoidosis, renal calculi or any malignancy
  • Patients on current treatment for tuberculosis
  • Pregnancy and Lactation
  • Women of childbearing potential not taking effective contraceptive measures.
  • Patients on long term glucocorticoids or anti-retroviral drugs
  • Patients on orlistat or other over the counter preparations that claim to block fat absorption.
  • A change in the type of medications for hypertension, diabetes mellitus and hyperlipidemia in the last three months
  • Patients who have undergone any form of bariatric surgery
  • Patients known to have any malabsorption disorders
  • Patients known to have osteoporosis or of baseline BMD scan shows osteoporosis as T score \<-2.5SD (for randomisation)
05

Study design

Phase
Phase 4
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
64 participants (actual)

Study arms

  • Active comparator
    Vitamin D supplementation

    Vitamin D3 tablets (cholecalciferol)

    Drug: Vitamin D supplementation

  • Placebo comparator
    Placebo pill

    Placebo pill

    Drug: Placebo Pill

Interventions

  • DrugVitamin D supplementation

    Vitamin D3 marketed by oneNine57

    Also known as: Vitamin D3-Cholecalciferol 1000units per tablet.

  • DrugPlacebo Pill

    Placebo pill supplied by oneNine 57 imported to Singapore with approval and import licence from HSA.

    Also known as: Placebo

06

What researchers measure

Primary outcomes

  1. Endothelial function as assessed by the reactive hyperemia index and endothelial progenitor cells

    Endothelial function will be tested by using the EndoPAT machine which measures the reactive hyperemia index and by estimating the no. of endothelial progenitor cells in the peripheral blood by flow cytometry.

    Time frame: 16 weeks

Secondary outcomes

  1. Markers of endothelial cell activation and thrombogenesis

    Biomarkers measured include hsCRP, e-selectin,von-willebrand factor(vWF)

    Time frame: 16 weeks

  2. No. of circulating endothelial cells and endothelial microparticles

    The no. of circulating endothelial cells and endothelial microparticles will be estimated before and after intervention.

    Time frame: 16-20 weeks

07

Study locations

1 site
  • Tan Tock Seng Hospital
    Singapore, 308433, Singapore
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 18, 2014, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT01741181
Lead sponsor
Tan Tock Seng Hospital
Collaborators
Duke-NUS Graduate Medical School, National Healthcare Group, Singapore
Responsible party
Rinkoo Dalan (Consultant, Tan Tock Seng Hospital) — Principal investigator
First posted
Dec 4, 2012
Start date
Sep 2012
Primary completion
Nov 2014
Completion
Nov 2014
Last update
Nov 18, 2014

Study contacts

Rinkoo Dalan, MBBS, FRCP
principal investigator · Tan Tock Seng Hospital

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Nov 2014. You cannot join it, but the record below documents what was studied.

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