IMPACT OF MONTHLY HIGH DOSE ORAL CHOLECALCIFEROL ON SERUM 25 HYDROXY VITAMIN D LEVELS IN BARIATRIC SURGERY SUBJECTS
Background: Vitamin D deficiency is a common problem in obese individuals both before and after bariatric surgery and may lead to bone mineralization problems and other health risks. Individuals having malabsorptive bariatric surgeries such as Roux-en-Y gastric bypass and duodenal switch surgeries are at increased risk of vitamin D malabsorption and deficiency. The ideal dose and form of vitamin D supplementation for patients after bariatric surgeries is still being debating, and more research is needed. Thus, the purpose of this study is to determine if a once monthly dose of 100,000 units of cholecalciferol results in an improvement of serum 25 hydroxy vitamin D levels in subjects having bariatric surgery.
Methods: A total of 32 morbidly obese subjects were randomly assigned to receive 100,000 IU of cholecalciferol monthly after bariatric surgery (TREATMENT: n=11) or no additional vitamin D after bariatric surgery (CONTROL: n=21). The CONTROL group received 1600 IU cholecalciferol with multivitamin and calcium daily while the TREATMENT group received an average total of 4933 IU cholecalciferol every day. Body Mass Index (BMI), serum 25 (OH) D, calcium, and % hemoglobin A1C were measured preoperatively and 3 months after bariatric surgery. Questionnaires were used to assess sun exposure, vitamin intake, tanning, medications, and any other supplement usage before each blood sample was taken.
Results: Three months after bariatric surgery, a significant increase was seen in mean serum 25 (OH) D levels (17.8±7.2 versus 33.8±14.7 ng/mL; P=0.01) in the vitamin D group receiving additional 100,000 IUs cholecalciferol per month. A significant difference was also observed in post-trial mean serum 25 (OH) D levels between the control and vitamin D groups (23.8 ± 10.7 vs 33.8 ± 14.7; P=0.04). A significant decrease was observed in serum calcium levels among CONTROL group subjects (9.4±0.4 versus 9.1±0.4 mg/dl; P=0.01).
Conclusion: The findings of this study showed 100,000 IUs cholecalciferol once a month is a safe and effective treatment for vitamin D deficiency and insufficiency in most patients having bariatric surgery.