Efficacy of Vitamin D Supplementation in Bariatric Surgery Patients

January 18, 2018 updated by: Vadim Sherman, MD

Preoperative Vitamin D Status and Efficacy of Therapeutic Vitamin D Supplementation Postoperatively in Bariatric Surgery Patients

As the use of bariatric surgery for treatment of extreme obesity adults continues to rise, clinicians must be aware of pre-existing nutritional deficiencies in overweight and obese patients. Nutritional deficiencies are common in patients undergoing bariatric surgery and these deficiencies should be detected and addressed early to avoid post-operative complications. To improve long-term outcomes following bariatric surgery, nutritional screening and prescribing appropriate supplementation to prevent nutrient deficiencies is needed. Vitamin D deficiency is common following bariatric surgery and has been reported to occur in 50-80% bariatric patients.The goal of this pilot study is to help develop nutrient supplementation interventions following two types of bariatric surgery: Roux-en Y gastric bypass and sleeve gastrectomy.

Recently, several studies in adults have revealed an inverse relationship between body fat and blood 25-hydroxyvitamin D3 [25(OH)D] levels, the relevant marker of low vitamin D status. Although vitamin D is well known for its essential role in bone metabolism and calcium homeostasis, increasing evidence is linking vitamin D to obesity. This study will evaluate vitamin D status during post operative daily supplementation of 2,000 IU of vitamin D3 and 1500 mg of calcium through assessment of changes in serum 25(OH)D, parathyroid hormone (PTH), calcium and phosphorus at baseline, 4 weeks, and 12 weeks following surgery. The dietary contribution of vitamin D and calcium will be estimated by food records analyzed using the University of Minnesota 2010 Nutrition Data System for Research (NDSR) program.

Primary Hypothesis: Daily supplementation with 2,000 IU of vitamin D3 for 12 weeks will significantly increase mean serum 25(OH)D levels in obese subjects following bariatric surgery compared to baseline levels.

Secondary Hypothesis: The percent response above baseline to daily supplementation with 2,000 IU of vitamin D3 will significantly differ between Roux-en Y and sleeve gastrectomy patients.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The prospective pilot study is designed to evaluate vitamin D status pre-operatively and post-operatively in 37 female patients undergoing either Roux-en Y gastric bypass or sleeve gastrectomy at The Methodist Hospital with 32 patients expecting to complete the 12 week trial. Women scheduled for either of these two types of bariatric surgery will be considered for inclusion in the pilot study. Based on previous research experience at The Methodist Hospital, the majority of bariatric patients are women. No children are treated at the Methodist Hospital bariatric center.

Subjects will be excluded if they have evidence of vitamin D deficiency (25(OH)D <20 ng/mL), hypercalcemia (calcium > 2.63 mmol/L), hypocalcemia (calcium < 1.75 mmol/L), renal insufficiency (GFR < 50 ml/min), or a history of primary hyperparathyroidism or renal tubular acidosis. Participants will be excluded if they take medications that interfere with vitamin D metabolism, have significant sun exposure, plan to travel to sunny climates during the study, or a history of hypercalcemia.

Baseline measures of serum 25(OH)D, PTH, calcium and phosphorus will be obtained. Values will be determined one week prior to surgery and during the follow-up visit at 12 weeks postoperatively. In addition, 25(OH)D will be measured at the 4th week post-operative clinic visit. Baseline information obtained will include age, height (centimeter), weight (kilogram), body mass index, sex, and race or ethnicity. A full medication list and medical history to identify any co-morbid conditions will be collected. Participants will be instructed to avoid traveling to sunny locations during the 12 week study.

Laboratory measurements pre-operative: 25(OH)D, PTH, CBC/Diff, glucose, calcium, albumin, total protein, sodium, potassium, CO2, BUN, creatinine, ALP, ALT, AST, bilirubin, lipid panel, ferritin, folate, iron, total iron binding capacity, hemoglobin A1c, insulin, vitamin B12, PT/PTT, TSH, HCG, C-reactive protein.

Laboratory measurements at week 4: 25(OH)D

Laboratory measurements at week 12: 25(OH)D, PTH, CBC/Diff, glucose, calcium, albumin, total protein, sodium, potassium, CO2, BUN, creatinine, ALP, ALT, AST, bilirubin, lipid panel, ferritin, folate, total iron binding capacity, vitamin B12, and TSH.

Nutrient intake assessments: Dietary intake of macronutrients, vitamin D, calcium, and other micronutrients will be assessed using the University of Minnesota 2010 Nutrition Data System for Research (NDSR) program. NDSR is a comprehensive nutrient calculation software program used for research purposes. The NDSR database contains values for 160 nutrients and includes more than 18,000 foods.

Participants' baseline laboratory will be used to measure the response to vitamin D and calcium supplementation over the course of 12 weeks. Bariatric patients participating in the study will be instructed to take a total of 1500 mg of calcium (as calcium citrate) plus 1000 IU of vitamin D3 as three chewable tablets (Celebrate ®). An addition 1000 IU of vitamin D3 per day will be taken as two chewable multi-vitamin bariatric supplements (Celebrate ®). Supplement compliance will be assessed by daily written records and inspection of supplement bottle containers at each clinic visit.

Serum 25(OH)D will be measured by ARUP Laboratories (Salt Lake City, UT, USA) using a chemiluminescent immunoassay. Serum calcium and phosphorus will be determined by The Methodist Hospital Clinical Chemistry Department as part of the standard bariatric protocol comprehensive metabolic panel. Intact PTH (iPTH) assays will be performed using the ADVIA Centaur ® XP Immunoassay System.

Vitamin D deficiency will be defined as 25(OH)D levels less than 20 ng/mL (50 nmol/L) and vitamin D insufficiency as 21 to 29 ng/mL (50 to 80 nmol/L). Secondary hyperparathyroidism will be defined as iPTH ≥ 70 ng/L. An increase in serum intact PTH level will be taken to be indicative of a possible negative calcium balance or a vitamin D deficiency (or both). Hypercalcemia will be defined as calcium > 2.63 mmol/L.

Statistical analysis:

Primary Hypothesis: Daily supplementation with 2,000 IU of vitamin D3 for 12 weeks will significantly increase mean serum 25(OH)D levels in obese subjects following bariatric surgery compared to baseline levels.

Secondary Hypothesis: The percent response above baseline to daily supplementation with 2,000 IU of vitamin D3 will significantly differ between Roux-en Y and sleeve gastrectomy patients.

Subject Withdrawal:

Participants will be withdrawn from the study if serum 25(OH)D levels are identified as within the deficient range so that the patient can receive needed treatment. A vitamin D deficiency will be defined as 25(OH)D concentrations less than 20 ng/mL (50 nmol/L) and vitamin D insufficiency as 21 to 29 ng/mL. In addition, if an abnormally high level of 25(OH)D is obtained (200 ng/mL or 500 nmol/L), we will have the 25(OH)D measurement repeated. If the second test is confirmed to be high, then we will withdraw that particular patient from the study for medical follow-up. If we find a trend of excess vitamin D among participants, however, we will re-evaluate and consider termination of the study.

Study Type

Interventional

Enrollment (Actual)

37

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Houston, Texas, United States, 77030
        • The Methodist Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria: Adult female obese patients undergoing either Roux-en Y gastric bypass or sleeve gastrectomy at The Methodist Hospital may participate in the study. Obese patients with a body mass index (BMI) > 40 or BMI >35 with a co-morbidity will be eligible.

-

Exclusion Criteria:Subjects will be excluded if they have evidence of vitamin D deficiency (< 20 ng/mL), hypercalcemia (calcium > 2.63 mmol/L), hypocalcemia (calcium < 1.75 mmol/L), renal insufficiency (GFR < 50 ml/min), or a history of primary hyperparathyroidism or renal tubular acidosis.Participants will be excluded if they take medications that interfere with vitamin D metabolism, have significant sun exposure, plan to travel to sunny climates during the study, or a history of hypercalcemia.

-

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Vitamin D3 and Calcium
Dietary supplement of vitamin D3 and calcium
Dietary supplement: Vitamin D3 and Calcium
1500 mg of calcium citrate plus 1000 IU of vitamin D3 and 1000 IU of vitamin D3 bariatric supplements per day
Other Names:
  • Celebrate ® calcium citrate plus vitamin D3
  • Celbrate ® multi-vitamin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Vitamin D Concentrations, Pre Operative and Post Bariatric Surgery Following 12 Weeks of Vitamin D Supplementation
Time Frame: baseline and 12 weeks
Serum 25(OH)D ng/ml levels at baseline and 12 weeks following bariatric surgery
baseline and 12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Serum 25-hydroxyvitamin D Levels at Baseline and 12 Weeks of Daily Vit D Supplementation Post Roux-en Y OR Sleeve Gastrectomy
Time Frame: Baseline and 12 weeks
We anticipate that vitamin D supplementation of Roux-en Y bariatric surgery patients will be less effective in improving or maintaining vitamin D status.
Baseline and 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vadim Sherman, MD

Collaborators

Texas Woman's University
The Methodist Hospital Research Institute

Investigators

  • Study Chair: Susan Miller, MD, The Methodist Hospital Research Institute
  • Principal Investigator: Vadim Sherman, MD, The Methodist Hospital Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2011

Primary Completion (Actual)

May 1, 2013

Study Completion (Actual)

September 1, 2015

Study Registration Dates

First Submitted

June 28, 2011

First Submitted That Met QC Criteria

June 28, 2011

First Posted (Estimate)

June 29, 2011

Study Record Updates

Last Update Posted (Actual)

January 23, 2018

Last Update Submitted That Met QC Criteria

January 18, 2018

Last Verified

January 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Pro00005625
  • 0311-0034 (Other Identifier: HMRI IRB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Obesity

Clinical Trials on Vitamin D3 and Calcium

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Slovakia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe