Vitamin (B1, B6, B12, D, and Folate) and Mineral (Iron, Selenium, and Magnesium) Status Across the Spectrum of Severe Obesity: An Integrative Multivariate Analysis of Metabolic and Nutritional Profiles.

Background: Obesity is frequently accompanied by metabolic dysfunction and micronutrient deficiencies, yet data on individuals with severe obesity (BMI ≥ 50 kg/m2) remain limited. Understanding how vitamin and mineral status changes across the adiposity continuum may optimize personalized nutritional management in severe obesity. Methods: We analyzed anthropometric, metabolic, hepatic, and micronutrient parameters in a retrospective, single-center cohort of adults evaluated before bariatric surgery, with a BMI range of 30 to 91 kg/m2 (mean 48.7 ± 8.7). Measurements included bioimpedance-derived body composition, liver elastography (CAP and stiffness), and fasting laboratory parameters, vitamins B1, B6, B12, D, and folate and minerals (iron, selenium, and magnesium). Correlation analysis, principal component analysis (PCA), and random forest (RF) classification were applied to identify the variables most strongly associated with BMI and metabolic phenotypes. Results: Several micronutrient concentrations, most notably vitamin D, folate and vitamin B6, declined progressively with increasing BMI. Vitamin D additionally correlated inversely with HbA1c. PCA revealed a separation of participants with extreme obesity driven by anthropometric and hepatic parameters, while micronutrients clustered inversely. RF classification identified HbA1c, hepatic enzymes (ALAT and γ-GT) and body-composition measures (waist circumference and visceral fat) as the strongest discriminators of T2DM, MASLD and high BMI, respectively. Combined MASLD and T2DM was associated with the most pronounced vitamin B6 depletion, whereas vitamin D was low across metabolic subgroups. Conclusions: Severe obesity is associated with distinct micronutrient depletion patterns that mirror metabolic deterioration. Integrating nutritional and metabolic profiling enables refined risk stratification and may, pending prospective validation, inform targeted supplementation strategies in individuals with severe obesity.