Vitamin D Supplementation Requirement in Obese Subjects

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.

Study Overview

• Status: Terminated
• Conditions: Vitamin D Deficiency
• Intervention / Treatment: Drug: placebo; Drug: Vitamin D3

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.

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Mineola, New York, United States, 11501
      • Winthrop University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Level of 25(OH)D	Vitamin D (25(OH)D) level at Baseline.	Baseline
Mean Level of 25(OH)D	Vitamin D (25(OH)D) level at Month 2.	Week 8

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Winthrop University Hospital
• Investigators: Principal Investigator: John Aloia,, MD, Winthrop-Unviersity Hospital

Study record dates

Study Major Dates

• Study Start: December 1, 2008
• Primary Completion (Actual): August 1, 2013
• Study Completion (Actual): August 1, 2013

Study Registration Dates

• First Submitted: October 15, 2009
• First Submitted That Met QC Criteria: October 15, 2009
• First Posted (Estimated): October 16, 2009

Study Record Updates

• Last Update Posted (Actual): July 3, 2023
• Last Update Submitted That Met QC Criteria: June 12, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Calcium-Regulating Hormones and Agents; Vitamin D; Cholecalciferol
• Other Study ID Numbers: 08028

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO