Causal associations between micronutrients and malignant neoplasms: a two-sample mendelian Randomization study

Background Malignant neoplasms remain a major global public health issue and are among the most serious diseases affecting human health. Micronutrients play a critical role in physiological processes, yet existing literature presents inconsistent findings regarding their relationship with malignancies. Methods A two-sample Mendelian randomization (MR) design was employed to investigate the potential causal associations between 15 micronutrients and the risk of malignant neoplasms. Summary statistics were sourced from large-scale genome-wide association studies (GWAS). MR analyses were conducted using inverse variance weighted (IVW), MR-Egger, weighted median, weighted mode, and simple mode methods. Selenium and folate were further analyzed using multivariable MR to assess independent effects. Result MR analysis revealed a significant inverse association between selenium levels and malignant neoplasms (OR = 0.96, 95% CI: 0.94–0.98, p = 0.002). Selenium remained independently associated with reduced cancer risk in multivariable MR analysis (OR = 0.967, 95% CI: 0.945–0.989, p = 0.003). Conversely, folate did not show an independent causal effect (p = 0.157). Conclusions These findings suggest selenium may have a protective role against malignant neoplasms. Further research is warranted to explore underlying mechanisms and validate these associations.