SOLARIS: Treatment of vitamin B12 and D deficiency after Stomach Reduction surgery

INTERVENTION: The study will evaluate 154 adult participants with vitamin B12 and D deficiency following bariatric surgery, distributed in a 1:1 ratio through stratified block randomization according to the surgical modality (sleeve gastrectomy or Roux‐en‐Y gastric bypass) performed on the REDcap platform. This is an open‐label clinical trial (without blinding). All participants in both groups will equally receive, continuously by oral route, 10 ml per day of the standard multivitamin Puravit Multi containing 750 mcg of vitamin A, 10 mcg of vitamin D3, 90 mg of vitamin C, 10 mg of vitamin E, 1.2 mg of vitamin B1, 1.3 mg of vitamin B2, 15 mg of micronutrient B3, 5 mg of vitamin B5, 2 mg of vitamin B6, 200 mcg of folic acid, and 6 mcg of vitamin B12. In the Experimental Group (77 participants), the treatment will be divided into two stages: in the Loading Phase, initiated at the baseline visit (D0), 1 sublingual tablet per day of the combination mecobalamin 1,000 mcg + cholecalciferol 7,000 IU will be administered until its complete dissolution, for 60 days; in the Maintenance Phase, initiated at the D60 visit, 1 sublingual tablet per day of mecobalamin 500 mcg + cholecalciferol 2,000 IU will be administered until complete dissolution, for an additional 90 days, completing 150 days of treatment. In the Active Control Group (77 participants), the treatment will also occur in two stages: in the Loading Phase, initiated at the baseline visit (D0), 1 intramuscular dose of hydroxocobalamin 5,000 mcg will be injected and the use of cholecalciferol 7,000 IU will be started, at 1 oral tablet per day for 60 days, with additional doses of 1 intramuscular dose of hydroxocobalamin 5,000 mcg injected at the follow‐up visits D15 and D30; in the Maintenance Phase, initiated at the D60 visit, the treatment will proceed with the administration of cholecalciferol 2,000 IU, at 1 oral tablet per day for an additional 90 days (until completing 150 days of the study), associated with a single intramuscular dose of hydroxocobalamin 5,000 mcg injected at the D90 visit. CONDITION: E02.650.500.062 vitamin D deficiency; vitamin B 12 Deficiency ; Bariatric Surgery PRIMARY OUTCOME: To evaluate the percentage of patients who achieved therapeutic success in correcting vitamin deficiencies between the treatment groups after 150 days; verified by the method of laboratory analysis of blood samples; using as parameters serum levels of 25OHD greater than 30 ng/mL and vitamin B12 greater than 300 pg/mL to determine the comparative efficacy rate between the interventions INCLUSION CRITERIA: Adult participants older than 18 years of age; history of bariatric surgery; diagnosis of vitamin D deficiency with levels below 30 ng/mL; diagnosis of vitamin B12 deficiency with levels below 300 pg/mL; ability to provide informed consent and follow the study protocol guidelines SECONDARY OUTCOME: To evaluate patient perception and experience regarding the proposed treatment; verified through the method of administering a specific perception questionnaire after 150 days; using as parameters the mean score obtained for the items of ease of medication administration, pain or discomfort during administration, and intention to continue using the treatment To evaluate the evolution of peripheral neuropathy symptoms in the participants; verified through the method of administering the Michigan Neuropathy Screening Instrument symptom questionnaire; using as parameters the comparison between the mean score obtained at baseline (D0) and after the end of the study (D150) To evaluate the percentage of patients who achieved therapeutic success during the loading and maintenance phases; verified by the method of laboratory analysis of blood samples; using as parameters serum levels of 25OHD greater than 30 ng/mL and vitamin B12 greater than 300 pg/mL measured after 60 days from the start of the study and after 150 days of the study To evaluate the temporal evolution of vitamin concentrations throughout the treatment; verified by the method of blood biochemical assay; using as parameters the comparison of the mean difference in serum values of 25OHD and vitamin B12 obtained at baseline and after 30, 60, 90, and 150 days of intervention