Serum Vitamin D, A, and E Concentrations and Their Associations with Chronic Diseases in Adult Patients Referred to Italian General Practitioners' Offices.

BACKGROUND

Vitamin deficiencies remain prevalent worldwide and contribute to chronic disease burden. This study evaluated serum concentrations of vitamins D, A, and E in Italian general practice populations and examined their associations with prevalent chronic diseases.

METHODS

This multicenter cross-sectional study enrolled 500 adult patients (median age: 60.7 years; 40.4% male) attending 21 general practice offices across Italy between January 2021 and December 2024. Serum concentrations of 25-hydroxyvitamin D [25(OH)D], vitamin A, and vitamin E were measured alongside demographic, clinical, and biochemical parameters. Statistical analyses included chi-square tests, correlation analyses, and stepwise logistic regression.

RESULTS

The median 25(OH)D concentration was 20.4 ng/mL, below optimal levels. Vitamin D deficiency was significantly associated with osteoporosis (p = 0.015), arterial hypertension (p = 0.047), and coronary artery disease (p = 0.002). The median vitamin A (654 μg/L) and vitamin E (11.3 mg/L) concentrations were within normal ranges. Notably, elevated vitamin A levels were significantly associated with arterial hypertension (p = 0.005), diabetes mellitus (p = 0.036), and cancer (p = 0.010). In the multivariate analysis, elevated vitamin A levels emerged as an independent predictor of multiple comorbidities (p < 0.001) and cancer presence (p = 0.014), alongside age, male gender, and body mass index.

CONCLUSIONS

Vitamin D insufficiency is highly prevalent in Italian primary care populations. Vitamin A concentrations show independent associations with multimorbidity and cancer, suggesting a potential negative influence of an animal-based diet, warranting prospective investigation. These findings highlight the importance of comprehensive vitamin assessment in general practice settings.