BACKGROUND: Diabetes mellitus (DM) is a globally growing chronic disease and is associated with numerous complications. In recent years, its potential impact on cognitive functions has gained increasing attention. This study was conducted to investigate the relationship between cognitive performance and micronutrient status in non-geriatric individuals with type 2 DM (T2DM). MATERIAL AND METHODS: This case-control study included 120 patients with T2DM aged 18-65 years. Patients with cognitive impairment constituted the case group, while age-matched patients without cognitive impairment served as controls, based on Montreal Cognitive Assessment scores. Individuals with malabsorption syndromes, severe acute or chronic illnesses, prior gastrointestinal surgery, dementia, Parkinson's disease, cerebrovascular events, psychiatric disorders, use of cognition-affecting medications, or micronutrient supplementation were excluded. Fasting blood glucose (FBG), HbA1c, renal and liver function tests, total protein, albumin, iron, zinc, magnesium, calcium, vitamin B12, folate, and vitamins A, C, D, and E were measured and compared between groups. RESULTS: 75 females and 45 males, a total of 120 patients were included in the study. The mean age was 53.0 ± 8.4 years. Cognitive dysfunction was present in 50% of the patients. There were no statistically significant differences in the levels of FBG, HbA1c, urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, folic acid, vitamin A, vitamin C, vitamin E according to age, gender, and cognitive dysfunction variables. Albumin, iron, zinc, magnesium, calcium, vitamin B12, vitamin D levels were significantly lower in the group with cognitive dysfunction than in the group without cognitive dysfunction. Albumin, iron, zinc, magnesium, calcium, vitamin B12, vitamin D levels in univariate model and iron, magnesium, calcium, vitamin B12 levels in multivariate model were effective in differentiating patients with and without cognitive dysfunction. CONCLUSION: This study shows that there is a significant relationship between cognitive functions and micronutrient levels in non-geriatric patients with DM. Screening of micronutrient levels and appropriate replacement of deficiencies during diabetes management is important for the protection and improvement of cognitive functions.