Abstract Roux‐en‐Y gastric bypass (RYGB) surgery is a highly effective technique for treating obesity. However, it may result in nutritional deficiencies. Here we report the case of a 55‐year‐old woman presenting with chronic diarrhea lasting 2 years, accompanied by lower limb paresthesia, macrocytic anemia, leukopenia, and thrombocytopenia. Her medical history included hypothyroidism treated with levothyroxine, and RYGB surgery performed in 2014, with intermittent micronutrient supplementation. The patient developed copper and zinc deficiencies. To our knowledge, this is the first report of a patient presenting with both deficiencies simultaneously with pancytopenia 10 years after RYGB. This case underscores the need to verify adherence to existing preoperative screening recommendations involving preoperative micronutrient measurements to assess micronutrient deficiency risks and multidisciplinary postoperative follow‐up, the importance of monitoring micronutrient levels, close follow‐up of both symptomatic and asymptomatic patients and evaluating adherence to supplementation regimens.