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Vitamin D Supplementation Requirement in Obese Subjects

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: NCT00996866
Recruitment Status : Completed
First Posted : October 16, 2009
Last Update Posted : December 15, 2014
Information provided by (Responsible Party):
Winthrop University Hospital

Brief Summary:
Vitamin D deficiency is common in obese patients. Most of vitamin D supplementation studies were done with non-obese subjects. This study looks at vitamin D supplementation requirements in obese patients as compared to non-obese subjects. This study also looks at changes in vitamin D level in obese patients undergoing medical weight loss. It is thought that obese patients have vitamin D deficiency through storage of vitamin D in the fat compartment not readily available for blood measurement. The investigators' hypothesis is that with medical weight loss vitamin D levels will increase in obese subjects.

Condition or disease Intervention/treatment Phase
Vitamin D Deficiency Drug: Vitamin D3 Drug: placebo Not Applicable

Detailed Description:

We intend to study changes in serum 25(OH)D level with calorie restricted weight loss in obese subjects. This will be a double dummy, placebo controlled randomized trial. Subjects whose serum 25(OH)D level is below 80 nmol/L will be assigned randomly to either the vitamin D supplemented or the placebo group. Those who are assigned to the placebo group will be weighed on a weekly basis and serum 25(OH)D level will be followed every 8 weeks for a minimum of 16 weeks and extended to the duration of weight loss along with serum calcium level. Changes in serum 25(OH)D level will be obtained with weight loss through restricted caloric intake.

To study the 25(OH)D dose-response curve with vitamin D supplementation in obese subjects, vitamin D supplemented group will receive initial daily vitamin D3 supplementation dose based on their baseline serum 25(OH)D level as described in Methods and Procedures section. Serum 25(OH)D levels will be drawn at 8 weeks and adjustments to the dose will be made based on the an algorithm to achieve serum 25(OH)D levels between 80 and 140 nmol/L. The dose-response curve obtained at 8 weeks will be compared to the one already established with non-obese subjects. Serum 25(OH)D level will be obtained at 16 weeks and compared with the data available from non-obese subjects.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 23 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: Vitamin D Supplementation Requirement in Obese Subjects
Study Start Date : December 2008
Actual Primary Completion Date : June 2011
Actual Study Completion Date : August 2011

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Placebo Comparator: Placebo
Half of subjects will be randomized to the placebo group.
Drug: placebo
The placebo group will receive sugar pills appearing similar to the vitamin D capsules.

Active Comparator: Vitamin D3
This is the study group that receives Vitamin D supplementation.
Drug: Vitamin D3
Vitamin D supplementation will follow an algorithm for initial vitamin D dosing and for dose changes. Subjects will receive 100 ug/day of vitamin D3 if their 25(OH)D level is less than 50nmol/L and 50 ug/day if their 25(OH)D level is between 50 and 80 ug/day.

Primary Outcome Measures :
  1. Mean level of 25(OH)D during calorie restricted weight loss from the placebo group. [ Time Frame: baseline and at 8 weeks ]

Secondary Outcome Measures :
  1. Dose response curve (the 'slope' i.e. the ratio of ∆ 25(OH)D/ initial vitamin D3 dose) in vitamin D supplemented group. [ Time Frame: 8 weeks ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Healthy men or women between the ages of 18 and 70 years old who are enrolled in our Weight Management Program with baseline BMI > 30 Kg/m2.

Exclusion Criteria:

  • Pregnancy,
  • Serum 25(OH)D level greater than 80 nmol/L,
  • Hypercalcemia (serum calcium level greater than the upper limit of normal),
  • Recent surgery or illness,
  • Those with chronic use of medications that influence calcium/vitamin D metabolism such as anti-convulsants, lithium and steroids. Thiazide diuretics for hypertension will be acceptable.
  • Subjects with sarcoidosis will be excluded.
  • Those who do not qualify to participate in the Weight Management Program will be excluded. They include subjects with active substance abuse and unstable cardiac disease.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00996866

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United States, New York
Winthrop University Hospital
Mineola, New York, United States, 11501
Sponsors and Collaborators
Winthrop University Hospital
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Principal Investigator: John Aloia,, MD Winthrop-Unviersity Hospital
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Responsible Party: Winthrop University Hospital Identifier: NCT00996866    
Other Study ID Numbers: 08028
First Posted: October 16, 2009    Key Record Dates
Last Update Posted: December 15, 2014
Last Verified: December 2014
Additional relevant MeSH terms:
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Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents
Calcium-Regulating Hormones and Agents