Efficacy of Vitamin D Supplementation in Bariatric Surgery Patients

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborator:
Texas Woman's University
Information provided by (Responsible Party):
Carolyn Moore, The Methodist Hospital System
ClinicalTrials.gov Identifier:
NCT01385098
First received: June 28, 2011
Last updated: August 2, 2013
Last verified: August 2013
  Purpose

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.


Condition Intervention
Obesity
Vitamin D Deficiency
Dietary Supplement: Vitamin D3 and Calcium

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Preoperative Vitamin D Status and Efficacy of Therapeutic Vitamin D Supplementation Postoperatively in Bariatric Surgery Patients

Resource links provided by NLM:


Further study details as provided by The Methodist Hospital System:

Primary Outcome Measures:
  • Improvement or maintenance of vitamin D status following bariatric surgery after 12 weeks of vitamin D3 supplementation. [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    Efficacy of supplementation with 2,000 IU of vitamin D3 for 12 weeks will significantly increase or maintain mean serum 25(OH)D levels in obese subjects following bariatric surgery compared to baseline levels.


Secondary Outcome Measures:
  • 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. [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    The percent response above baseline to daily supplementation with 2,000 IU of vitamin D3 will be compared between Roux-en Y and sleeve gastrectomy patients. We anticipate that vitamin D supplementation of Roux-en Y bariatric surgery patients will be less effective in improving or maintaining vitamin D status.


Estimated Enrollment: 37
Study Start Date: July 2011
Estimated Study Completion Date: December 2013
Primary Completion Date: May 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

  Hide Detailed Description

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.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

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.

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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.

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  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01385098

Locations
United States, Texas
The Methodist Hospital
Houston, Texas, United States, 77030
Sponsors and Collaborators
The Methodist Hospital System
Texas Woman's University
  More Information

Publications:
Responsible Party: Carolyn Moore, Associate Professor, The Methodist Hospital System
ClinicalTrials.gov Identifier: NCT01385098     History of Changes
Other Study ID Numbers: 0311-0034
Study First Received: June 28, 2011
Last Updated: August 2, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by The Methodist Hospital System:
Vitamin D
Bariatric surgery
Roux-en Y surgery
Gastric sleeve surgery
Parathyroid Hormone

Additional relevant MeSH terms:
Obesity
Vitamin D Deficiency
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Avitaminosis
Deficiency Diseases
Malnutrition
Calcium, Dietary
Cholecalciferol
Vitamin D
Ergocalciferols
Vitamins
Bone Density Conservation Agents
Physiological Effects of Drugs
Pharmacologic Actions
Micronutrients
Growth Substances

ClinicalTrials.gov processed this record on July 20, 2014