Vitamin and Mineral Deficiency 12 Years After Roux-en-Y Gastric Bypass a Cross-Sectional Multicenter Study

Micronutrient deficiencies are common after Roux-en-Y gastric bypass (RYGB). This study explores whether vitamin and mineral deficiency was associated with adherence to recommended supplementation 12 years after RYGB.

The cross-sectional Bariatric Surgery Observation Study (BAROBS) was conducted in 2018-2020 at three hospitals in Central Norway. We report data on 490 patients' self-reported adherence to recommended supplements and vitamin and mineral levels in the blood. The patients, who had RYGB between 2003 and 2009, were recommended an over-the-counter multivitamin-mineral supplement, calcium/vitamin D (1000 mg/20 µg) and vitamin B₁₂ injections (reimbursed), since bariatric supplements were not available then.

Mean (SD) age was 40.1 ± 9 years at RYGB, and time to follow-up 11.7 ± 1.6 years. Of 490 patients, 393 (80%) were women. Among 361 (74%) patients' adherent to multivitamin-mineral supplements; folate, vitamin B_2, and vitamin B₆ deficiency were present in 39 (11%), 103 (29%), and 63 (17%) patients, respectively. The same deficiencies occurred in 44 (34%), 67 (52%), and 67 (52%) patients' non-adherent to recommendations. Although 466 (95%) patients reported adherence to vitamin B₁₂ supplements, sub-optimal levels were found in 73 (16%) patients. Though 336 (69%) patients adhered to calcium/vitamin D supplements (1000 mg/20 µg), sub-optimal vitamin D levels (< 75 nmol/l) were found in 174/336 (52%) adherent patients and 120/154 (78%) non-adherent patients.

Twelve years after RYGB, adherence to supplements, though in sub-optimal doses of new recommendations, decreases the probability of vitamin and mineral deficiency, especially for thiamine, vitamin B₂, vitamin B₆, folate, vitamin B₁₂, and vitamin D, but does not eliminate it.