Search Results (1,679)

Objective: Visceral adipose tissue is a primary driver of insulin resistance and dysglycemia in type 2 diabetes (T2D), yet its clinical assessment remains challenging. This study aimed to validate neck circumference (NC) as a novel, practical anthropometric biomarker for estimating visceral fat area (VFA) and identifying metabolic risk in a T2D cohort, facilitating its integration into public health and primary care screening strategies. Methods: In a cross-sectional study of 1139 T2D patients, we collected data on NC, biochemical parameters (fasting plasma glucose, hemoglobin A1c, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides), and precisely measured VFA and subcutaneous fat area (SFA) via bioelectrical impedance analysis (Omron HDS-2000). We employed Pearson’s correlation and multivariate logistic regression to analyze the relationship between NC and metabolic indicators. Receiver operating characteristic (ROC) curve analysis was used to establish sex-specific NC cut-off values for predicting abnormal VFA. Results: The cohort comprised 687 (60.3%) males and 452 (39.7%) females. NC demonstrated strong positive correlations with VFA (p < 0.001), as did body mass index (BMI), waist–hip ratio (WHR), and SFA. In males, NC was further positively correlated with key metabolic biomarkers including fasting insulin, Insulin Resistance Index, triglycerides, and creatinine. ROC analysis identified NC > 39.5 cm for males and >35.5 cm for females as the optimal cut-off points for detecting abnormal visceral adiposity, highlighting its diagnostic utility. Conclusions: NC serves as a highly accessible and effective biomarker for visceral adiposity and associated metabolic dysfunction in patients with T2D. The established sex-specific cut-off values provide a simple, non-invasive tool for risk stratification in clinical and public health settings, enabling early intervention and improved management of metabolic disease. Full article

Type 2 diabetes mellitus (T2DM) and obesity represent a growing global public health challenge, strongly associated with excess body weight, unhealthy dietary habits, and a sedentary lifestyle. The ketogenic diet (KD), characterized by very low carbohydrate intake, moderate protein intake, and high fat consumption, induces a metabolic state known as ketosis, in which the body switches from glucose to fat as its primary energy source. KD has gained increasing interest as a strategy to improve glycemic control, reduce body weight, and improve lipid profiles in individuals with obesity and T2DM. The purpose of this narrative review is to summarize the current scientific evidence on the effects of KD on key metabolic parameters, including blood glucose levels, glycated hemoglobin (HbA1c), body weight, and body composition. The analysis is based on peer-reviewed articles retrieved from PubMed, Embase, and Scopus with particular emphasis on clinical studies that provide robust evidence on the efficacy and safety of KD in the treatment of metabolic disorders. Full article

Background/Objectives: The Prognostic Nutritional Index (PNI), which integrates serum albumin and lymphocyte count, reflects both nutritional and inflammatory status. However, its role in early renal function decline among patients with type 2 diabetes (T2D), particularly in relation to glycemic control, remains unclear. This study aimed to: (1) characterize the dose–response relationship between PNI and early renal function decline in type 2 diabetes using restricted cubic splines; (2) identify whether glycemic control (HbA1c) modifies the PNI–renal decline association; and (3) evaluate the clinical utility of combining PNI and HbA1c for risk stratification. Methods: We analyzed data from 1711 community-based participants with T2D who had preserved renal function at baseline. The PNI was calculated as serum albumin (g/L) + 5 × lymphocyte count (×10⁹/L). The primary outcome was a composite of rapid estimated glomerular filtration rate (eGFR) decline (>3 mL/min/1.73 m² per year) or incident chronic kidney disease (CKD) stage 3. Restricted cubic spline models, multivariable regression, and Johnson–Neyman analyses were used to examine non-linearity and effect modification by glycated hemoglobin (HbA1c). Results: A consistent inverse linear association was observed between PNI and the rate of eGFR decline (P for non-linearity > 0.05). Johnson–Neyman analysis further demonstrated that the protective association of PNI was statistically significant within an HbA1c range of 7.24% to 8.71%. Stratification by clinical cut-offs revealed a significant effect modification by glycemic status. The inverse linear association between PNI and renal risk was most pronounced under hyperglycemic stress, as evidenced by the markedly elevated incidence (50.0%) among individuals with both poor glycemic control (HbA1c ≥ 8%) and low PNI (<50). Conversely, under good glycemic control (HbA1c < 8%), this inverse association was substantially attenuated, with a lower incidence observed in the low-PNI subgroup (6.7%) than in the high-PNI subgroup (15.9%). These findings indicate that the protective role of PNI is conditional upon the glycemic milieu. Conclusions: The PNI demonstrates a stable linear association with early renal function decline in T2D, with its protective effect most pronounced at suboptimal HbA1c levels. Combining PNI and HbA1c effectively identifies a high-risk subgroup characterized by synergistic risk, underscoring the need for integrated nutritional and glycemic management. Full article

Background/Objectives: The Mediterranean (Med)-style and Dietary Approaches to Stop Hypertension (DASH) eating patterns are evidence-based nutrition interventions given their protective effects from cardiometabolic diseases. Little is known about adherence to each eating pattern among the Hispanic/Latine population. The objective of this cross-sectional analysis is to assess the alignment of reported dietary intakes of Hispanic/Latine adults to Med-style and DASH eating patterns and associations with clinical outcomes for diabetes mellitus and cardiovascular diseases. Methods: A sample of 5406 Hispanic/Latine adults from the National Health and Nutrition Examination Survey (2007–2018) was utilized. Alignment to the Med-style and DASH eating patterns was calculated by scoring indices tailored for overconsumption in the United States. Multiple linear regression determined associations between each respective eating pattern and clinical outcomes. Results: Hispanic/Latine adults in the United States have a mean DASH score of 11.2 and a Med-style score of 8.4 (out of 100), indicating poor alignment. Adjusted regression analysis showed increased alignment of both eating patterns was associated with a decrease in average blood pressure (DASH ꞵ = −0.095, p = <0.0001; Med-style: ꞵ = −0.128, p = 0.0002). Greater adherence to a Med-style eating pattern score was also associated with improved average hemoglobin A1c (ꞵ −0.007, p = 0.017). Neither diet pattern score was associated with total cholesterol. Conclusions: Evidence of low alignment to the Med-style and DASH eating patterns among Hispanic/Latine populations exacerbates the need for future work to understand cultural tailoring of evidence-based eating patterns to increase adherence and support improved cardiometabolic outcomes. Full article

Background/Objectives: Branched-chain fatty acids (BCFAs) exhibit a range of biological activities; however, their limited natural abundance and high cost have constrained in vivo research. Lanolin represents a promising source for enriching BCFAs. Nevertheless, the in vivo application, safety, and dose-effect relationship of BCFAs derived from lanolin (BCFAs-DFL) remain unassessed. Methods: In this study, the acute toxicity in C57BL/6J mice was first evaluated for 7 days by a single oral administration of 5000 mg/kg BW of BCFAs-DFL. Subsequently, 40 mice were divided into four groups (control group, low dose of 100 mg/kg BW, medium dose of 300 mg/kg BW, and high dose of 600 mg/kg BW) and were continuously administered by gavage for 28 days to study the effects of BCFAs-DFL on the growth, blood biochemistry, intestinal morphology, and intestinal flora of the mice. Results: In the acute toxicity test, BCFAs-DFL exhibited no lethality or abnormalities in mice, indicating its non-toxic nature. Throughout the 28-day trial, mice in the medium- and high-dose groups experienced a notable decrease in average daily feed intake (p < 0.05), yet their weight gain remained unaffected (p > 0.05). Hemoglobin and hematocrit levels declined in the high-dose group (p < 0.05). Conversely, serum aspartate aminotransferase and total bilirubin levels escalated in the medium- and high-dose groups, while triglycerides and urea nitrogen levels decreased (p < 0.05). The serum’s total antioxidant capacity and immunoglobulin levels (IgA, IgG) rose in proportion to the dosage (p < 0.05). BCFAs-DFL notably enhanced the villus height of the jejunum and ileum in mice (p < 0.05). Gut microbiota analysis indicated no significant impact on overall α and β diversity. Conclusions: The 28-day intervention revealed that BCFAs-DFL can modulate feeding behavior, TG, T-AOC, and immunoglobulin levels in mice. Additionally, it promotes the development of intestinal villi. Based on various indicators, a dosage of 100 mg/kg BW effectively induces beneficial metabolic regulation, such as the reduction of triglycerides, without causing a burden on liver metabolism. This dosage may represent a more suitable application for potential use. Full article

Background: Intravascular hemolysis is a common complication in patients undergoing extracorporeal membrane oxygenation (ECMO), with plasma free hemoglobin (pfHb) serving as a biomarker for detection. Without standardized protocols, laboratories face challenges in interpreting and reporting results. Hemolysis indices may enhance reporting accuracy. Methods: This retrospective observational study at University Hospital Center Zagreb included 61 lithium heparin plasma samples from ECMO patients. pfHb was measured using the Harboe method (fHb) and estimated from hemolysis indices on Abbott Alinity c analyzer (efHb). Total and conjugated bilirubin, hemolysis, icterus, and lipemia indices (HIL) were recorded. Method comparison used Passing-Bablok regression and Bland–Altman analysis. An algorithm for pfHb reporting accounting for HIL interferences was developed. Results: Significant differences were observed between methods, with Harboe yielding higher median fHb (261 mg/L) versus efHb (58 mg/L). Regression analysis showed constant negative bias of −91 mg/L (95% CI: −143 to −16) for efHb relative to fHb. Bland–Altman analysis demonstrated wide limits of agreement. Correlation between fHb and efHb was moderate (Spearman’s rho = 0.618, p < 0.001). The delta between methods increased with higher bilirubin concentrations. An algorithm integrating HIL indices with the Harboe method was developed to guide result validation and reporting. Conclusions: Accurate hemolysis assessment in ECMO patients requires careful interpretation, appropriate method selection, and laboratory–clinician collaboration. The proposed algorithm improves the clinical utility of pfHb testing by accounting for analytical interferences and supporting informed decision-making. Full article

This study evaluated the effects of water renewal rate and temperature on the growth performance and physiological responses of juvenile Piaractus brachypomus reared in a recirculating aquaculture system (RAS). A total of 336 fish (1.35 ± 0.24 g) were distributed in six RAS units under two water renewal rates (42 and 128 L h⁻¹) and three temperatures (26, 29, and 32 °C) for 45 days. Temperature was the main factor affecting growth, with higher final weight and total length at 29 and 32 °C throughout the experimental period. Water renewal rate significantly influenced feeding efficiency and energy allocation. Higher renewal (128 L h⁻¹) increased dissolved oxygen and daily feed intake and resulted in higher hemoglobin levels and hepatic lipid deposition, particularly at 32 °C, indicating greater metabolic activity. Conversely, the lower renewal rate (42 L h⁻¹) was associated with better feed conversion ratios at 29 °C and higher muscle lipid content at 26 °C, suggesting reduced energy expenditure. Hematocrit, total plasma protein, and cholesterol were primarily influenced by temperature, with higher values at 29 and 32 °C, while glucose, triglycerides, and liver enzymes were unaffected. Overall, temperatures of 29–32 °C optimized growth, while water renewal rate modulated feed utilization, physiological responses, and lipid deposition. These findings highlight the importance of jointly optimizing temperature and water renewal rate in RAS to enhance growth performance and metabolic balance in juvenile P. brachypomus. Full article

Background/Objectives: Type 2 diabetes (T2D) is a chronic metabolic disorder closely linked to cardiovascular disease and obesity and notably influenced by lifestyle and dietary patterns. The Mediterranean diet has well-established benefits across multiple cardiometabolic risk factors, including those relevant to diabetes. This study aimed to investigate the degree to which adults with T2D adhere to a Mediterranean dietary pattern and to examine how such adherence relates to glycemic and lipidemic regulation. Methods: This cross-sectional study included 100 adults with T2D (54 men and 46 women). Adherence to the Mediterranean diet was assessed using the Mediterranean Diet Score (MDS). Demographic, anthropometric, lifestyle, and clinical data were collected, and glycemic and lipid parameters were analyzed. Associations between Mediterranean diet adherence and metabolic outcomes were examined using correlation analyses and multivariable regression models adjusted for relevant confounders. Results: Most participants showed low adherence to the Mediterranean diet. A significant inverse association was observed between Mediterranean diet adherence and hemoglobin A1c (HbA1c) levels, with individuals scoring ≤35 on the MDS demonstrating higher HbA1c levels. Similar trends were observed in the lowest tertile of adherence. Notably, each one-point increase in MDS predicted a 0.13% reduction in HbA1c. In multivariable regression analyses, Mediterranean diet adherence remained the strongest predictor of glycemic control, independent of age, body mass index (BMI), sex, smoking status, physical activity and the number of antidiabetic treatments. Higher adherence was also significantly associated with lower low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels, as well as higher high-density lipoprotein cholesterol (HDL) concentrations. Conclusions: Greater adherence to the Mediterranean diet is independently associated with improved glycemic regulation and a more favorable lipid profile in adults with T2D. These findings support the Mediterranean diet as a valuable non-pharmacologic strategy for optimizing metabolic outcomes in people with T2D. Full article

Plants from the Zingiberaceae family, particularly Zingiber officinale, Curcuma longa, and Alpinia galanga, are rich sources of bioactive compounds with documented antidiabetic and anti-inflammatory properties. This review summarizes current evidence on their phytochemical profiles and pathways relevant to metabolic regulation. Key compounds, including gingerols, shogaols, curcuminoids, and phenylpropanoids, support glucose homeostasis by enhancing insulin sensitivity, promoting Glucose Transporter Type 4 (GLUT4)-mediated glucose uptake, improving β-cell function, and modulating metabolic signaling pathways such as PI3K/Akt, AMPK, PPARγ, and NF-κB. Their potent antioxidant and anti-inflammatory activities further reduce oxidative stress and chronic low-grade inflammation, both central to the progression of type 2 diabetes and its complications. Evidence from selected clinical and experimental studies suggests that dietary supplementation with whole-rhizome preparations or standardized extracts (including formulation-enhanced products) may improve fasting blood glucose (FBG), glycated hemoglobin (HbA1c), lipid metabolism, and oxidative stress markers. Recent advances in delivery systems, including nanoemulsions, liposomes, and curcumin–piperine complexes, substantially enhance the bioavailability of poorly soluble phytochemicals, strengthening their therapeutic potential. Overall, Zingiberaceae plants emerge as promising natural supplements in nutritional and pharmacological strategies targeting diabetes. Further clinical research is required to refine dosage, confirm long-term efficacy, and support their integration into evidence-based metabolic interventions. Full article

Background: The aim of this study was to evaluate the diagnostic and prognostic performance of albumin-based inflammatory–nutritional indices in hyperemesis gravidarum (HG) and to determine their associations with disease severity and risk of re-hospitalization. Methods: This retrospective case–control study included 246 women with HG and 246 gestational-age-matched healthy pregnant controls at 6–16 weeks of gestation. Disease severity was classified as mild, moderate, or severe using the Pregnancy-Unique Quantification of Emesis (24 h scale) (PUQE-24) score. A comprehensive panel of albumin-based inflammatory indices—including C-reactive protein-to-albumin ratio (CAR), fibrinogen-to-albumin ratio (FAR), neutrophil-to-albumin ratio (NAR), leukocyte-to-albumin ratio (LAR), neutrophil percentage-to-albumin ratio (NPAR), monocyte-to-albumin ratio (MAR), hemoglobin–albumin–lymphocyte–platelet (HALP) score, modified HALP (m-HALP) score, prognostic nutritional index (PNI) score, systemic immune-inflammation index-to-albumin (SII/Alb), and systemic inflammatory response index-to-albumin (SIRI/Alb)—was calculated from routine complete blood count and serum biochemistry results obtained at diagnosis. Receiver operating characteristic analysis, along with univariate and multivariate logistic regression models, was performed to evaluate diagnostic performance and identify predictors of severe HG and re-hospitalization. Results: Albumin-based indices exhibited severity-associated alterations, with an overall trend toward worsening immuno-nutritional status across increasing HG severity. Among these, m-HALP score demonstrated the strongest inverse correlations with PUQE-24 score, ketonuria grade, length of hospital stay, and re-hospitalization risk (r = −0.74 to −0.52; all p < 0.001) and achieved the highest discriminative accuracy for both severe HG (AUC 0.864, 95% CI 0.836–0.892, p < 0.001) and re-hospitalization (AUC 0.722, 95% CI 0.675–0.766, p < 0.001). In multivariable analysis, higher HALP, m-HALP, and PNI were independently associated with a lower likelihood of severe HG. For re-hospitalization, higher m-HALP and HALP were independently associated with a lower risk, whereas higher NPAR, higher ketonuria grade, and higher PUQE-24 score were independently associated with an increased risk of re-hospitalization. Conclusions: Albumin-based indices, particularly m-HALP, demonstrated robust diagnostic and prognostic performance in HG compared with conventional biomarkers. These readily available, cost-neutral composite biomarkers enable objective severity stratification and accurate identification of patients at elevated risk of recurrent hospitalization, offering immediate potential to guide personalized, evidence-based clinical management. Full article

Prediabetes is a serious and major global problem afflicting approximately 21% of the world’s population. It is the intermediate stage between normal glucose levels and type 2 diabetes mellitus (T2DM). Prediabetes is associated with major complications including the development of T2DM and increased cardiovascular disease (CVD). It can be easily diagnosed with an inexpensive plasma glucose level and/or a hemoglobin A1c (HbA1c) measurement. The mainstay of treatment is intensive lifestyle (ILS) intervention, including reduction in calories, especially saturated fats, refined carbohydrates, etc., coupled with regular physical activity of 150 min per week since ILS changes, with at least a 5% weight loss, have been shown to reduce progression to T2DM in multiple studies globally. Also, metformin therapy has been shown to prevent the progression to T2DM. In conclusion, serious consideration by guideline committees to classify prediabetes as a disease is highly recommended based on its global burden, easy and cost-effective diagnosis, association with serious conditions of diabetes and CVD, and effective ILS intervention. Therapy targeting those at an especially high risk for T2DM, such as persons with impaired glucose tolerance (IGT), impaired fasting glucose (IFG) with values ≥ 110 mg/dL (6.1 mmol/L), and/or HbA1c ≥ 6.0% (42 mmol/mol) coupled with overweightness or obesity. Full article

Circulating irisin, a myokine implicated in energy expenditure and adipose tissue regulation, has been increasingly studied as a potential biomarker of metabolic dysfunction. This study evaluated the relationship between serum irisin and metabolic indices, including the atherogenic index of plasma (AIP), the lipid accumulation product (LAP), and hypertriglyceridemic-waist (HTGW) phenotype in individuals with prediabetes (PreDM) and newly diagnosed type 2 diabetes mellitus (T2DM). A total of 138 participants (48 PreDM, 90 T2DM) were assessed for anthropometric, glycemic, and lipid parameters. Serum irisin levels were measured by enzyme-linked immunosorbent assay (ELISA) and correlated with insulin resistance indices (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Quantitative Insulin Sensitivity Check Index (QUICKI)), glycemic control (glycosylated hemoglobin A1c (HbA1c)), and composite lipid markers (total triglycerides-to-high-density lipoprotein cholesterol (TG/HDL-C)). Group differences were evaluated using non-parametric tests; two-way ANOVA assessed interactions between phenotypes and markers; multiple linear regression (MLR) and logistic regression models explored independent associations with metabolic indices and HTGW; receiver operating characteristic (ROC) analyses compared global and stratified model performance. Serum irisin was significantly lower in T2DM than in PreDM (median 140.4 vs. 230.7 ng/mL, p < 0.0001). Irisin levels remained comparable between males and females in both groups. Post hoc analysis shows that lipid indices and irisin primarily distinguish HTGW phenotypes, especially in T2DM. In both groups, irisin correlated inversely with HOMA-IR, AIP, and TG/HDL-C, and positively with QUICKI, indicating a possible compensatory role in early insulin resistance. MLR analyses revealed no independent relationship between irisin and either AIP or LAP in PreDM, while in T2DM, waist circumference remained the strongest negative predictor of irisin. Logistic regression identified age, male sex, and HbA1c as independent predictors of the HTGW phenotype, while irisin contributed modestly to overall model discrimination. ROC curves demonstrated good discriminative performance (AUC = 0.806 for global; 0.794 for PreDM; 0.813 for T2DM), suggesting comparable predictive accuracy across glycemic stages. In conclusion, irisin levels decline from prediabetes to overt diabetes and are inversely linked to lipid accumulation and insulin resistance but do not independently predict the HTGW phenotype. These findings support irisin’s role as an integrative indicator of metabolic stress rather than a stand-alone biomarker. Incorporating irisin into multi-parameter metabolic panels may enhance early detection of cardiometabolic risk in dysglycemic populations. Full article

Background: A strikingly unusual pattern with a possible up-field shift in Hemoglobin A1c (HbA1c) and A0 (HbA0) peaks and an unexplained hemoglobin F (HbF) peak with capillary electrophoretic shift in the HbA1c chromatograms of a leukemia patient were found while performing a HbA1c screen. Methods: A review of the patient’s history with an exhaustive search of the literature ruled out medications as interfering factors or contributing to the abnormal findings. Other than hyperleukocytosis, the patient did not have the aberrant HbF peak noted previously in the electrophoresis or contributing factors. We hypothesized that the irregular chromatographic pattern and wrong location of the HbA1c peak, hereafter referred to as the downfield shift in the electrophoretic species, was due to various glycation or fructosamine adducts and derivatives within the HbA1c and A0 protein. Results: A literature search offered little guidance. However, the instrument troubleshooting measures suggested a hemoglobin variant or exogenous transfusion as a putative source for the HbF peak, while the downfield shift in the chromatogram remained unexplained. Full article

Background: Feto-maternal hemorrhages (FMHs) due to placenta disruption and bleeding from fetal maternal circulation can lead to life-threatening fetal anemia. These hemorrhages are more often of small volume and remain unreported. Sensitization to fetal red blood cell (RBC) antigens can occur during pregnancy, at delivery, or after invasive procedures. The sensitized mother produces IgG antibodies (abs) that cross the placenta and cause the hemolysis of fetal RBCs, release of hemoglobin, and increased levels of unconjugated bilirubin in the fetus or neonate. The result is hemolytic disease of the fetus and newborn (HDFN). Methods: In this study, we aim to provide a structured overview of RBC alloimmunization in pregnancy. A literature search was conducted using PubMed. English articles published from January 2010 to October 2025 were selected by the authors. The contributing manuscripts focused on managing RBC alloimmunization in pregnancy, FMH screening and quantification, antenatal and postnatal testing, Rh immune globulin (Rh Ig or Anti-D) prophylaxis, and national registry data. Results: Frequencies of RBC abs vary among American, Caucasian, and Asian populations because of genetic diversity, different antibody detection and antibody identification methods, and FMH tests. More specifically, the erythrocyte rosette is a simple screening test for FMH. A positive rosette must be quantified by the Kleihauer–Betke (KB) or flow cytometry (FC). The KB results may be overestimated or underestimated. The advantages of FC include high accuracy, specificity, and repeatability. Ultimately, anti-D prophylaxis protocol varies from country to country. Conclusion: Maternal alloimmunization is an uncommon and highly variable event. Although introducing anti-D prophylaxis has decreased the Rh immunization rate, it is still an unmet medical need. In brief, mitigation strategies for RBC alloimmunization risk include accurate maternal and neonatal testing at different time points, adequate Rh immune globulin prophylaxis in D-negative pregnant women, preventing sensitizing events, adopting a conservative transfusion policy, and upfront ABO and Rh (C/c, E/e) and Kell matching in females under 50 years of age. Full article

Background/Objectives: Chronic low-grade inflammation and nutritional deficiencies, particularly vitamin D deficiency, have emerged as important contributors to Metabolic syndrome (MetS) pathogenesis but remain underexplored. This study aimed to comprehensively evaluate the associations between dietary intake, vitamin D status, and inflammatory biomarkers (high-sensitivity C-reactive protein -CRP- and ferritin) in patients with MetS. Methods: A cross-sectional observational study was conducted on 141 adult MetS patients at a Mexican hospital. Clinical, anthropometric, dietary (using a validated food frequency questionnaire), and biochemical data including serum 25-hydroxyvitamin D, CRP, ferritin, and neutrophil-to-lymphocyte ratio (NLR) were collected. Vitamin D deficiency was defined as serum 25(OH)D < 20 ng/mL, and high inflammation as CRP ≥ 3 mg/L. Logistic regression models adjusted for confounders were used to analyze associations. Mediation analysis assessed whether vitamin D deficiency mediated the link between dietary intake and high CRP or ferritin. Results: Patients with elevated CRP had significantly lower serum vitamin D levels (14.0 ± 5.1 vs. 22.1 ± 7.0 ng/mL; p < 0.001). Multivariable analysis showed vitamin D deficiency (adjusted OR 7.1; 95% CI 2.5–19.4; p < 0.001) and hyperferritinemia (ferritin ≥ 200 μg/L; aOR 8.0, 95% CI 3.5–18.2, p < 0.001) as predictors of high CRP. Conversely, hyperferritinemia was predicted by vitamin D deficiency (aOR 24.69; 95% CI 3.76–162.16; p = 0.001), elevated CRP (aOR 5.06; p = 0.014), Hb (aOR 63.23; p < 0.001), and inversely by grade 2 obesity (aOR 0.11; 95% CI 0.02–0.60; p = 0.03), confirming bidirectional CRP-ferritin associations and hyperferritinemia as an inflammation marker rather than iron overload indicator. Although Hb > 14.3 g/dL associated with hyperferritinemia, it did not independently predict CRP in multivariate analyses. Frequent consumption of vitamin D-rich foods (milk, fish, Manchego and Oaxaca cheese) was associated with lower inflammation. Mediation analysis confirmed that vitamin D deficiency mediated dietary intake-CRP and dietary intake-ferritin links (Sobel test p < 0.05). Conclusions: Vitamin D deficiency is a key mediator linking inadequate dietary vitamin D intake to systemic inflammation in MetS. Nutritional strategies emphasizing vitamin D repletion and consumption of vitamin D fortified foods may effectively reduce chronic inflammation and improve metabolic outcomes. Full article