Objective To investigate the causal relationships between various circulating micronutrients and aneurysms at different sites using Mendelian randomization (MR) analysis. Methods Summary-level genetic data for 15 common blood micronutrients, including vitamin D, calcium, iron, copper, selenium, zinc, folate, carotene, vitamin C, vitamin B12, vitamin E, magnesium, vitamin B6, omega-3 fatty acids, and homocysteine, were obtained from the IEU Open GWAS database. Genetic associations with aneurysms, including intracranial aneurysm and thoracic aortic aneurysm, were retrieved from the GWAS Catalog and the FinnGen consortium. Bidirectional MR analyses were performed using seven MR approaches, with the inverse-variance weighted (IVW) method as the primary analysis. Multiple sensitivity analyses and visualization tools were used to assess pleiotropy and heterogeneity. Furthermore, multivariable MR was applied to explore the interactions and independent effects of multiple micronutrients on aneurysm risk, and meta-analysis was employed to integrate results from different data sources and minimize bias. Results Through multiple MR and sensitivity analyses, combined with multivariate MR and meta-analysis, the results confirmed that elevated blood levels of vitamin D could significantly increase the risk of intracranial aneurysm [odds ratio (OR)=1.65, 95% confidence interval (CI) (1.20, 2.29), P=0.002], while omega-3 fatty acids [OR=0.82, 95%CI (0.73, 0.92), P=0.001] could significantly reduce the risk. For thoracic aortic aneurysm, selenium [OR=1.08, 95%CI (1.00, 1.15), P=0.042] and folate [OR=1.45, 95%CI (1.13, 1.87), P=0.004] were identified as potential risk factors. No heterogeneity or horizontal pleiotropy was detected, and no reverse causality was found between micronutrients and aneurysm development. Conclusions Variations in circulating micronutrient levels can influence the risk of aneurysm development. These findings provide new insights into the potential roles of micronutrients in aneurysm prevention and treatment and offer a scientific basis for developing targeted clinical intervention strategies.