In Vitro Diagnostics (IVD) is central to precision medicine, enabling disease screening, diagnosis, and therapeutic monitoring. While mass spectrometry (MS) remains the dominant platform for metabolomics, Nuclear Magnetic Resonance (NMR) spectroscopy has emerged as a robust complementary technology due to its high reproducibility, quantitative reliability, and non-destructive nature. This review systematically evaluates the role of NMR-based metabolomics in clinical IVD, focusing on applications in oncology, cardiovascular disease, and neurology. This study critically examines technical strengths and limitations and identifies key barriers to clinical translation, particularly in standardization, data harmonization, and regulatory validation. Finally, we propose a framework to facilitate the integration of NMR into routine clinical workflows.