Trends in vitamin D level and risk of vitamin D deficiency after gastrectomy for gastric cancer: A retrospective study of a single high-volume center experience.

BACKGROUND & AIMS: Post-gastrectomy vitamin D deficiency can result in osteoporosis and fractures, which can decrease patient quality of life and increase their socioeconomic burden. However, because there is no consensus around preoperative measurement and regular postoperative monitoring of serum vitamin D [25(OH)vitD] level for gastric cancer patients, we performed a retrospective study with a single high-volume center experience.

METHODS

We reviewed a database of 614 gastric cancer patients who underwent curative gastrectomy between December 2015 and December 2019. Multivariate analyses were performed to identify risk factors for 25(OH)vitD deficiency after one year postoperative (n = 546). A linear mixed model was used to evaluate changes between preoperative (n = 585) and postoperative (6 [n = 504] and 12 months [n = 572]) 25(OH)vitD values.

RESULTS

Preoperative 25(OH)vitD deficiency occurred in 67.7% of patients with gastric cancer. Patients who underwent postoperative chemotherapy for advanced pathologic disease were more likely to be 25(OH)vitD deficient at postoperative year one than those who did not receive chemotherapy (P = 0.005). Postoperative chemotherapy was an independent risk factor along with preoperative 25(OH)vitD level for one year postoperative 25(OH)vitD deficiency (P = 0.002). Meanwhile, there was significant change in 25(OH)vitD level after surgery according to reconstruction (increased in Billroth I group compared to gastrojejunostomy group, P = 0.016), pathologic stage (increased in stage I group, decreased in stage II and III group, P = 0.005), postoperative chemotherapy (increased in non-chemotherapy group, decreased in chemotherapy group, P = 0.001), and season of surgery (increased when the blood tests were performed at summer, decreased when tested in non-summer season, P = 0.009).

CONCLUSION

More than half of gastric cancer patients had preoperative 25(OH)vitD deficiency, and those who had postoperative chemotherapy were at risk for 25(OH)vitD deficiency one year after surgery. There was a significant change in 25(OH)vitD level after surgery according to reconstruction method and postoperative chemotherapy. Preoperative measurement and regular postoperative monitoring should be considered for high-risk patients.