The Effect of VItamin D Supplementation on Nutritional STatus and Adverse Outcomes in Bariatric Surgery (VISTA)

An estimated 2 in 3 American adults are either overweight (BMI 25-29.9 kg/m2) or obese (BMI 30-39.9 kg/m2). The prevalence of obesity, morbid obesity (BMI 40-44.9 kg/m2), and even super obesity (BMI ≥ 45 kg/m2) are increasing. Obesity is a leading contributor to global mortality and contributes to the burden of disease associated with diabetes, cardiovascular disease, musculoskeletal disorders such as osteoarthritis, and some cancers. Morbid obesity reduces life expectancy by 8 to 10 years, similar to the effect of being a regular cigarette smoker.

Several studies have demonstrated that most obese adults are vitamin D (VitD) insufficient (<75 nmol/L, 30 ng/ml) or deficient (<50 nmol/L, 20 ng/ml). The inverse relationship between body mass index (BMI) or body fat mass and VitD status is hypothesized to be due to sequestration of VitD by adipose tissue, reducing the bioavailability of VitD. The classical role of VitD is in the maintenance of bone calcification, but more recent research has elucidated a more varied role for this hormone. Lack of VitD has been associated with increased susceptibility to infection, autoimmunity, cancer, and chronic disease.

Bariatric surgery is currently the most successful means of long-term weight loss. Since deficiency in fat-soluble vitamins, such as VitD, is considered a metabolic complication of bariatric surgery, determining the VitD status of these individuals and perhaps correcting it prior to surgery may prove greatly beneficial. Potential complications relating to VitD insufficiency and deficiency include adverse surgical outcomes such as improper wound healing, infection of the surgical incision, and atrial fibrillation. Since the indications for bariatric surgery are obesity and obesity-related comorbidities, bariatric surgery patients are at an increased risk of having an adverse surgical outcome.

The Johns Hopkins Center for Bariatric Surgery (JHCBS) is designated as a Center of Excellence by the American College of Surgeons. To comply with this designation, the center must maintain a certain standard of care (SoC) and minimize complication rates. Given the potential relationship between VitD status and adverse surgical outcomes, the investigators are currently reviewing pre-operative VitD status (serum 25(OH)D concentration) collected as routine SoC and investigating the relationship with surgical outcomes under an Institutional Review Board (IRB) approved protocol (NA_00087502). The investigators findings reveal that most of bariatric surgery patients are VitD insufficient and deficient pre-operatively. To date, there is no standard regarding treating these deficiencies pre-operatively and as such the center does not intervene prior to surgery. A randomized, double-blinded, placebo-controlled pilot trial is needed to assess the causality of the relationship between pre-operative VitD status and adverse surgical outcomes in the bariatric surgical patient.

The investigators plan to identify new patients approved for bariatric surgery at the JHCBS. These patients will be randomized consecutively in a 1:1 ratio to either 30 days of 10,000 International Units (IU) of VitD3 plus SoC or 30 days of placebo plus SoC immediately prior to surgery. The investigators will monitor these patients for any adverse surgical outcomes, including wound infection, dehiscence, and prolonged length of hospital stay. The investigators will also monitor their long-term clinical outcomes such as malnutrition, weight loss, and resolution of comorbidities at their routine clinic care visit: 2 weeks, 6 weeks, 3 months, 6 months, and 12 months post-operatively. At these visits the patients are assessed for wound healing, weight loss, nutritional status, and other key markers of health, such as vital signs.