Vitamin D Deficiency, Obesity, and Metabolic Parameters in Chilean Older Adults

Background/Objectives: Vitamin D deficiency and obesity are prevalent public health concerns among older adults, with potential impacts on metabolic health. Despite high deficiency rates reported globally, data on their relationship in Chilean older populations remain limited. This study investigates the relationship between 25(OH)D status, obesity, and metabolic parameters in Chilean older adults using data from the 2016-2017 National Health Survey (ENS). Methods: A cross-sectional analysis was conducted in 1252 individuals aged ≥ 65 years with complete 25(OH)D and anthropometric measurements. Plasma levels of 25(OH)D were classified as optimal ≥ 30 ng/mL, insufficiency 20-29.9 ng/mL, deficiency 12-19.9 ng/mL, and severe deficiency < 12 ng/mL. Logistic regression models adjusted for age, sex, education, comorbidities, and environmental factors were used to assess associations. Results: The results demonstrated that 88.3% of older adults had 25(OH)D ≤ 30 ng/mL, with 58.3% presenting deficiency. Obesity was an independent risk factor for vitamin D deficiency across all models. Geographic location, female sex, and smoking also influenced deficiency risk, while no significant associations emerged with type 2 diabetes or hypertension. Conclusions: These findings highlight the need for targeted strategies addressing vitamin D insufficiency in older adults, considering regional and lifestyle factors, to improve health outcomes in this vulnerable population.