Clinical trial NCT00996866: Vitamin D Supplementation Requirement in Obese Subjects
Official title: Vitamin D Supplementation Requirement in Obese Subjects
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Vitamin D Deficiency
Lead sponsor: Winthrop University Hospital
Sponsor class: OTHER
First posted: 2009-10-16
Enrollment: 27
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

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.

Primary outcomes:
measure: Mean Level of 25(OH)D
timeFrame: Baseline
measure: Mean Level of 25(OH)D
timeFrame: Week 8
Secondary outcomes:
Other outcomes:
Locations:
city: Mineola
country: United States
facility: Winthrop University Hospital
state: New York
Study officials:
affiliation: Winthrop-Unviersity Hospital
name: John Aloia,, MD
role: PRINCIPAL_INVESTIGATOR
References: