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Effects of Vitamin D Supplementation on Glucose Metabolism in Women With Former Gestational Diabetes Mellitus

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: NCT01992133
Recruitment Status : Completed
First Posted : November 25, 2013
Last Update Posted : November 25, 2013
Information provided by (Responsible Party):
Toh-Peng Yeow, RCSI & UCD Malaysia Campus

Tracking Information
First Submitted Date  ICMJE November 12, 2013
First Posted Date  ICMJE November 25, 2013
Last Update Posted Date November 25, 2013
Study Start Date  ICMJE June 2011
Actual Primary Completion Date August 2012   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: November 18, 2013)
Change in glucose metabolism as assessed by change in Insulin sensitivity index as calculated by HOMA -IR28 [ Time Frame: 6 months ]
Original Primary Outcome Measures  ICMJE Same as current
Change History No Changes Posted
Current Secondary Outcome Measures  ICMJE
 (submitted: November 18, 2013)
  • Change in Insulin Sensitivity index as calculated by Oral Glucose Insulin Sensitivity Index (OGIS) [ Time Frame: 6 months ]
  • Change in plasma 25-OH- Vitamin D level pre and post replacement [ Time Frame: 6 months ]
Original Secondary Outcome Measures  ICMJE Same as current
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Effects of Vitamin D Supplementation on Glucose Metabolism in Women With Former Gestational Diabetes Mellitus
Official Title  ICMJE The Effects of Vitamin D Supplementation on Blood Glucose and Markers of Metabolic Syndrome in Women With Vitamin D Deficiency and Previous Gestational Diabetes Mellitus
Brief Summary Gestational Diabetes Mellitus (GDM) and vitamin D deficiency are related to insulin resistance and impaired beta-cell function, with heightened risk for future development of diabetes. The investigators hypothesize that vitamin D supplementation to women with previous gestational diabetes may improve glucose metabolism.
Detailed Description

Gestational diabetes mellitus (GDM) is a state of glucose intolerance occurring during pregnancy and is related to both resistance to peripheral action of insulin and impairment of beta (β)-cell function. Its transient presence during pregnancy alerts to a heightened risk of diabetes in the future. About 10-50% of women with GDM develop diabetes mellitus later on in life. Data from Malaysia found that 50% of GDM women had developed diabetes at an interval of five to seven years post index pregnancy. Therefore, it is paramount that the investigators identify effective measures to prevent diabetes progression in this high-risk group.

Vitamin D deficiency has been shown to be associated with insulin resistance and impaired pancreatic function. Vitamin D deficiency is more prevalent in women with GDM and low vitamin D levels correlate with insulin resistance.

Interventional studies using vitamin D supplement in an attempt to modify glucose metabolism have yielded mixed results. This may be partly due to variable doses of supplementation used, short duration of follow up and inappropriate target group. A very short duration of less than seven days of supplementation may not be sufficient to demonstrate the potential beneficial effects. Previous studies suggested vitamin D replacement improved glucose metabolism in selected populations only. Benefit was seen in subjects with impaired fasting glucose but not in normal volunteers, nor in patients with established chronic diabetes. It is possible that vitamin D can help with early stage of disturbance in glucose handling, but is unable to augment insulin secretion in subjects with chronic diabetes and exhausted pancreatic function. Lack of adequate dosing may have also accounted for the failure of many previous studies to demonstrate beneficial effects of vitamin D replacement. Adequate vitamin D supplementation would ideally raise blood 25-hydroxyvitamin D (25(OH)D) levels above 80nmol/L because diabetes risk is lowest at this vitamin D level. Supplementation with 4000IU of vitamin D3 per day in a population of South Asian women with proven vitamin D deficiency safely restored the vitamin D level and improved insulin resistance.

Very little is known about the relationship between vitamin D status and glucose metabolism in women with former GDM. This study aimed to evaluate the effect of adequate vitamin D supplementation on insulin sensitivity, pancreatic β-cell function and markers of cardio-metabolic risk in Malaysian women with former GDM and vitamin D insufficiency.

Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Condition  ICMJE
  • Gestational Diabetes Mellitus in Pregnancy
  • Vitamin D Deficiency
Intervention  ICMJE
  • Dietary Supplement: Vitamin D3
  • Dietary Supplement: Placebo
Study Arms  ICMJE
  • Experimental: Vitamin D3
    Vitamin D3 at 4000 iu per day for 6 months
    Intervention: Dietary Supplement: Vitamin D3
  • Placebo Comparator: Placebo
    matching placebo- capsules containing soya oil at 4 capsules a day for 6 months
    Intervention: Dietary Supplement: Placebo
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: November 18, 2013)
Original Actual Enrollment  ICMJE Same as current
Actual Study Completion Date  ICMJE August 2012
Actual Primary Completion Date August 2012   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Women with Gestational Diabetes (GDM) on the most recent pregnancy- between 6 and 48 months post partum at time of recruitment to study
  • Previous GDM defined as-Fasting plasma glucose ≥ 7.0 mmol/l or 2-h plasma glucose ≥ 7.8 mmol/l on 75g OGTT performed during gestation OR As determined by treating physician during index pregnancy
  • With no plan to conceive again within the 6 months of study duration
  • With 75g OGTT at study baseline confirming either Normal respond, Impaired Fasting Glucose (IFG) or Impaired Glucose Tolerance (IGT)
  • Vitamin D deficiency at baseline - defined as Plasma 25-(OH) D concentration of between 15 and 50nmol/L

Exclusion Criteria:

  • Pregnancy or Breast feeding
Sex/Gender  ICMJE
Sexes Eligible for Study: Female
Ages  ICMJE Child, Adult, Older Adult
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Malaysia
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT01992133
Other Study ID Numbers  ICMJE NMRR-10-679-6202
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Toh-Peng Yeow, RCSI & UCD Malaysia Campus
Study Sponsor  ICMJE RCSI & UCD Malaysia Campus
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Principal Investigator: Toh Peng Yeow, MB BCH BAO, FRCP(Edin) Penang Medical College, 4 Jalan Sepoy Lines, 11450, Penang, Malaysia
PRS Account RCSI & UCD Malaysia Campus
Verification Date November 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP