Schizophrenia (SCZ) and antipsychotic use are associated with clinically significant weight gain and subsequent increased mortality (1). The prevalence of obesity and other modifiable cardiometabolic risk factors (e.g., smoking, type-2 diabetes mellitus (T2DM), hypertension, dyslipidemia, and metabolic syndrome) is higher in individuals with SCZ, with relative risks for each factor ranging between 1.5 and 5 compared with the general population (2).

The weighted lifetime prevalence of SCZ varies by country and region between 0.3 and 1.3% (3). Chronic forms of SCZ experience marked cognitive impairment with multiple negative symptoms that invalidate social behavior (4).

SCZ most frequently appears in late adolescence or between 20 and 30 years of age, and in men it usually manifests earlier than in women, despite not being as common as many other mental disorders (5). People with SCZ are two to three times more likely to die prematurely than the general population, often from cardiovascular, metabolic, or infectious diseases (6).

1,25 (OH)₂D₃ (vitamin D) is well-recognized as a neurosteroid that modulates multiple brain functions. Vitamin D could be involved in the clinical presentation of psychotic disorders, and the correlation has been implicated in meta-analysis (7–9). A growing body of evidence indicates that vitamin D plays a pivotal role in brain development, neurotransmission, neuroprotection, and immunomodulation (7). Accumulating data show that there may be an association between vitamin D deficiency and SCZ (9), and also, low maternal vitamin D was proposed as a risk factor for SCZ almost two decades ago (10). However, the precise molecular mechanisms by which vitamin D exerts these functions in the brain are still unclear (7).

Multiple risk factors, such as genetic, environmental factors (9), as well as psychiatric patients’ lifestyle (11) and antipsychotic drugs (12) may contribute to vitamin D deficiency, leading to a high risk of general dysfunction (13).

Patients with SCZ and bipolar disorder (BD) had significantly lower bone mineral density (BMD) and significantly higher prevalence of low bone mass and osteoporosis compared with healthy controls. Binary regression analysis showed that SCZ or BD was an independent risk factor for low bone mass and osteoporosis. In addition, sex, age, and bone turnover markers also influenced the occurrence of low bone mass and osteoporosis (14). A multiple regression analysis by Carswell et al. found an increased risk of low BMD associated with lower folate and glycated hemoglobin levels, older age, and higher serum ferritin and follicle-stimulating hormone (FSH) levels. In female patients, BMD was mainly associated with age and serum hormones (FSH and testosterone), whereas BMD in male patients was mainly related to age, trace elements (serum ferritin and 25-hydroxyvitamin D [25(OH)D]), and parathyroid hormone (15).

There is an increased risk of chronic kidney disease (CKD) amongst people who have severe mental illness compared with those who do not. However, people who have severe mental illness and CKD are less likely to receive specialist nephrology care (16). Individuals with severe mental illness, including conditions such as SCZ and BD, are at a higher risk of developing CKD. Higher incidences of CKD in this population can be partially explained by known risk factors, such as treatment with lithium carbonate and higher rates of cardiovascular disease (17).

Although nutritional status plays a critical role in health outcomes, there is a paucity of data on the nutritional profiles of Latin American patients diagnosed with SCZ. Most existing research has focused on North American and European populations, leaving a gap in understanding dietary intake, anthropometric parameters, and micronutrient deficiencies in Latin American contexts. This deficiency in evidence hinders the development of personalized nutritional interventions and public health strategies. Comprehensive studies are urgently needed to elucidate nutritional status and inform robust, culturally appropriate, and evidence-based guidelines for this vulnerable demographic.

Our hypothesis is that individuals with SCZ will exhibit increased visceral adiposity and reduced serum levels of 25-hydroxyvitamin D [25(OH)D] compared with those without SCZ. The purpose of our study was to analyze the nutritional status of patients with SCZ and other mental illnesses.

This study shows a high prevalence of anemia, low vitamin D levels, low HDL cholesterol, high total cholesterol, low bone mass, and low serum creatinine levels. Visceral fat and body fat percentage were variables that have a high impact on nutritional status and should be constantly monitored. According to the GLIM criteria, including phenotypic components (weight loss, low body mass index, and reduced muscle mass) and etiological components (reduced food intake or assimilation and inflammation), none of our participants met the definition of malnutrition.

These results are noteworthy because the external catering service provided nutritious meals to the patients, and most of them spent several hours physically active and exposed to sunlight. A study from China found that the rate of anemia in patients with CZS was 26.36% (18). A study in a Palestinian population found that 55.9% of women and 13.7% of men with CZS suffered from anemia (19). Furthermore, chronic psychiatric patients in Turkey had a high prevalence of anemia (25.4%), including BD, psychotic disorder, conversion disorder, obsessive-compulsive disorder, generalized anxiety disorder, and other psychiatric conditions. It was also determined that women (35%) with SCZ suffer more from anemia than men (10%) with the same disorder (20).

The frequency of anemia was highest among patients with a psychotic disorder (35%). Vitamin B12 deficiency may be related to psychiatric symptoms and imbalance. Previous studies have shown that vitamin B12 deficiency can lead to psychiatric symptoms (21–24).

The prevalence of anemia and vitamin D deficiency in patients with SCZ may vary substantially across regions due to differences in dietary intake, sun exposure, healthcare infrastructure, and sociocultural factors. In Qatar, recent cross-sectional studies reveal suboptimal levels of hemoglobin, ferritin, and vitamin D among patients with SCZ, with inflammatory and metabolic abnormalities, such as BMI (25–28). Elevated HbA1c and triglycerides are prominent, especially in treatment-resistant cases. These metabolic alterations, potentially driven by antipsychotic-induced weight gain and chronic low-grade inflammation, may impair iron metabolism and reduce vitamin D bioavailability. Furthermore, intense sun avoidance due to cultural dress codes and limited nutritional screening programs worsens micronutrient deficiencies. Together, these findings highlight the critical role of integrative and context-specific nutritional surveillance in the care of SCC.

Anemia-induced cerebral hypoxia and oxidative stress impair neurotransmitter metabolism, particularly serotonin and glutamate, increasing the risk of suicide. A recent longitudinal study of major depressive disorder identified a low baseline red blood cell count as a significant predictor of suicidal ideation trajectories, suggesting erythrocyte-mediated modulation of neuroinflammatory circuits (e.g., IL-6 and TNFα). These findings imply that anemia and decreased red blood cell function contribute to suicidality by disrupting oxygen delivery and inflammatory pathways. The overall prevalence of serum 25(OH) D < 75 nmol/L (21.63 ng/mL) was estimated to be 76.6% between 2000 and 2022 (29).

This result is similar to that of a study published in the New England Journal. Vitamin D deficiency is a major challenge worldwide and does not appear to be exclusive to patients with multiple sclerosis (30). A study conducted in the Netherlands, which evaluated serum vitamin D levels in 118 participants, showed that 65.8% of those diagnosed with SCZ had low vitamin D levels (≤12 ng/mL: deficient + insufficient) (31). Another study, conducted between 2018 and 2022 in Ecuadorian cities, such as Quito, Ambato, Ibarra, and Santo Domingo, reported that approximately 68.8% of participants from the general population had serum 25(OH) D levels < 30 ng/mL (32).

Several studies have reported a high prevalence of fracture risk and osteoporosis in patients with SCZ (14, 33). Marthoenis et al. found that compared with healthy individuals, patients with SCZ had a higher prevalence of underweight and a lower prevalence of overweight and obesity. They also reported that SCZ diagnosis was significantly associated with reduced muscle mass, reduced bone mass, higher basal metabolic rate, older metabolic age, and increased total body water (34). In contrast, Tang et al. found no evidence to support a definitive association between mental illness and osteoporosis risk, contradicting many previous observational studies (35).

Risk factors for hepatic steatosis are similar in both the general population and patients with SCZ (36). Patients with SCZ have increased intra-abdominal fat, which could explain their premature death (37). A study conducted in Russia revealed that the median body fat in 110 patients with CZS without metabolic syndrome was 29.9% (38). Marthoenis et al. showed a mean of 25.1 and 7.6% for the percentage of body fat and visceral fat in patients with multiple sclerosis (CZS), similar to our results (34).

Regarding low serum creatinine levels, one possible factor is the occurrence of pharmacological side effects resulting from the use of specific medications or interactions with others. It is possible that psychiatric illnesses may cause indirect damage to muscle tissue, the liver, or the kidneys through as yet unidentified mechanisms, resulting in abnormal serum creatinine levels.

Although the majority of patients have general diets (89% in our sample), INC dietitians indicate specialized diets depending on the case. Most patients use the entire area (about 200 square meters for men and the same for women) to walk at their individual discretion. They sporadically leave the area with technical support. They have a markedly sedentary life, which could contribute to the worsening of their condition.

Quetiapine and chlorpromazine, via H1/5HT2C receptor antagonism, potentiate SREBP1c–driven de novo lipogenesis, increasing visceral adiposity. Carbamazepine induces CYP2R1 and other P450s, accelerating 25-hydroxyvitamin D catabolism, thereby lowering its serum levels. Pregabalin and biperiden have minimal metabolic impact, whereas levomepromazine shares anticholinergic effects that can alter appetite. Levothyroxine elevates basal metabolic rate, preserving lean mass; metformin activates AMPK, mitigating insulin resistance and visceral fat; carvedilol modulates lipid oxidation and oxidative stress; losartan’s AT1R blockade reduces inflammation and may normalize creatinine. Chronic IL6 and TNFα excess further impair iron homeostasis and bone turnover.

Our study integrates anthropometric measures and bioimpedance derived body composition analysis with detailed biochemical profiling in adults with chronic SCZ. Its innovative design not only addresses nutritional disparities within the target region but also evaluates visceral adiposity, BMD, nutrient status, and renal biomarkers to inform comprehensive clinical care strategies.

The limitations of our study include a small sample size and a lack of tests related to creatinine. Further studies could explore creatinine using tests such as glomerular filtration rate, creatinine clearance, and albumin–creatinine ratio. The cut-off points for body composition are based on data from the US and Europe, rather than Latin America. Additional testing, including dual-energy X-ray absorptiometry, procollagen I N-terminal propeptide, and osteocalcin, among other potential candidates, could facilitate a more comprehensive understanding of bone health. Moreover, the secondary effects of drugs on the body, diets, sample sizes, and epigenetic mechanisms require further investigation.

Here we suggest some recommendations. In chronic SCZ care, mental health clinicians should:

The findings of this study highlight the high prevalence of anemia, low vitamin D levels, low HDL, high total cholesterol, low bone mass, and low serum creatinine in individuals with chronic SCZ and other mental illnesses. These results emphasize the need for targeted nutritional interventions to address these deficiencies and improve overall health outcomes. The significantly higher visceral fat accumulation in patients with SCZ suggests that metabolic alterations, possibly linked to antipsychotic medication use and dietary habits, could contribute to increased cardiovascular and metabolic risks.

Given the markedly sedentary lifestyle observed in this population, structured physical activity programs should be incorporated into treatment plans to mitigate the risks associated with obesity, metabolic syndrome, and osteoporosis. Future research should explore the molecular mechanisms underlying metabolic alterations in SCZ, the long-term impact of nutritional deficiencies on cognitive function, and the effects of psychiatric medication on metabolic health. A multidisciplinary approach, including psychiatric, nutritional, and physical health interventions, is essential to improve the quality of life for individuals with chronic SCZ.