PREOPERATIVE VITAMIN D REPLETION STRATEGIES IN BARIATRICMETABOLIC SURGERY: A SYSTEMATIC REVIEW

Background
Although preoperative vitamin D deficiency rates are reported as up to 90% among bariatric-metabolic surgery candidates, evidence on optimal preoperative repletion strategies to guide practice is lacking.

Objectives
To determine the effect of preoperative vitamin D deficiency repletion strategies on pre- and postoperative vitamin D
status and adverse event rates among bariatric-metabolic surgery candidates.

Methods
A systematic review searching four databases was conducted in August 2022 to synthesise interventional or observational studies that delivered preoperative vitamin D to metabolic-bariatric surgery candidates via oral, intravenous, or
intramuscular (IM) routes. Eligible studies were critically appraised, and the GRADE approach evaluated confidence
in findings.

Results
From 10,926 search results, 14 studies (n=21 repletion groups: n=8 from n=4 interventional studies and n=13 from
n=10 observational studies) reported preoperative repletion of vitamin D, with 10 of 14 studies analysing the results
before and after the intervention/surgery (Table 1). Quality was moderate (n=2 positive; n=12 neutral). All n=21
groups reported improved 25OHD levels. One of four studies measuring adverse events reported mild-moderate
symptoms related to supplement use.

Conclusion
All preoperative vitamin D repletion strategies improved 25OHD levels. The strongest evidence was moderate certainty that preoperative vitamin D oral supplementation for 7-8 weeks improved 25OHD levels.