Vitamin D Supplementation Requirement in Obese Subjects

NCT ID: NCT00996866

Last Updated: 2023-07-03

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: NA
• Total Enrollment: 27 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-12-31
• Study Completion Date: 2013-08-31

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.

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.

Conditions

Vitamin D Deficiency

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Placebo

Half of subjects will be randomized to the placebo group.

Group Type: PLACEBO_COMPARATOR

placebo

Intervention Type: DRUG

The placebo group will receive sugar pills appearing similar to the vitamin D capsules.

Vitamin D3

This is the study group that receives Vitamin D supplementation.

Group Type: ACTIVE_COMPARATOR

Vitamin D3

Intervention Type: DRUG

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.

Interventions

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.

Intervention Type: DRUG

placebo

The placebo group will receive sugar pills appearing similar to the vitamin D capsules.

Intervention Type: DRUG

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Winthrop University Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

John Aloia,, MD

Role: PRINCIPAL_INVESTIGATOR

Winthrop-Unviersity Hospital

Locations

Winthrop University Hospital

Mineola, New York, United States

Countries

United States

Other Identifiers

08028

Identifier Type: -

Identifier Source: org_study_id