Patients with severe obesity undergoing bariatric surgery often have micronutrient deficiencies, especially if they have inflammation. A study found that 85.5% of these patients had at least one deficiency, with vitamin D being the most common. High levels of C-reactive protein (CRP), a marker of inflammation, were seen in 65% of patients and were linked to deficiencies in vitamin B12 and folate. Patients with high CRP also had more micronutrient deficiencies overall. The study suggests that checking for multiple deficiencies may be important in patients with high CRP levels before surgery.