Patients with type 2 diabetes (T2D) are at risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD). We investigated the prevalence of compensated advanced chronic liver disease (cACLD) and steatosis in patients with T2D using the new non-invasive diagnostic methods of shear wave measurements (SWMs) and attenuation (ATT) measurements in comparison with those of vibration-controlled transient elastography (VCTE) and the controlled attenuation parameter (CAP), which served as the reference methods. Among 214 T2D patients, steatosis at any grade and cACLD were revealed in 134 (62.6%) and 19 (8.9%) patients, respectively. SWMs showed a high correlation with VCTE (Spearman’s ρ = 0.641), whereas SWMs produced lower (mean of −0.7 kPa) liver stiffness measurements (LSMs) overall. At a LSM of >11.0 kPa (Youden), SWMs had an AUROC of 0.951 that was used to diagnose cACLD (defined as a LSM of >15 kPa through VCTE) with 84.2% sensitivity and 96.4% specificity. The performance of ATT measurements in diagnosing liver steatosis at any grade (defined as the CAP of ≥274 dB/m) was suboptimal (AUROC of 0.744 at the ATT measurement cut-off of >0.63 dB/cm/MHz (Youden) with 59% sensitivity and 81.2% specificity). In conclusion, the prevalence of liver steatosis and previously unrecognized cACLD in patients with T2D is high and SWMs appear to be a reliable diagnostic method for this purpose, whereas further investigation is needed to optimize the diagnostic performance of ATT measurements.

B-group vitamins (B1, B2, B3, B5, B6, B7, B9, B12) are water-soluble micronutrients essential for energy metabolism, one-carbon metabolism, neurotransmitter synthesis, and redox homeostasis. This chapter provides a comprehensive clinical review of B-vitamin status across internal medicinegynaecology, and neurology. In obesity and diabetes, B-vitamin insufficiency frequently coexists with metabolic dysfunction, contributing to insulin resistance, endothelial dysfunction, and cardiovascular risk, with metformin, GLP-based therapies, and bariatric surgery further depleting B12 and folate. In female reproductive medicine, folate-mediated one-carbon metabolism modulates ovulation, implantation, and pregnancy outcomes, with additional specificities in polycystic ovary syndrome and sickle cell disease. Neurologically, B-vitamin deficiency remains an important reversible cause of encephalopathy, myelopathy, peripheral neuropathy, and cognitive decline, while vitamin B6 excess causes dose-dependent sensory neuropathy. In elderly patients, age-related physiological and socioeconomic changes increase deficiency risk, particularly for B12. The chapter emphasizes shared mechanisms of B-vitamin metabolism and deficiencies, including homocysteine regulation, outlines practical monitoring strategies using functional biomarkers, addresses drug-nutrient interactions, and provides evidence-based supplementation guidelines. A unified, precision-medicine approach integrating early recognition, appropriate laboratory evaluation, and targeted supplementation/therapy optimizes outcomes across disciplines.