Nutrients · Sep 20, 2025

Differential Associations of Vitamin D Metabolites with Adiposity and Muscle-Related Phenotypes in Korean Adults: Results from KNHANES 2022-2023

By Kim SH, Jeong Y, Son SW et al.

BACKGROUND: Body composition plays a crucial role in metabolic health, aging, and the development of various diseases. Vitamin D has been implicated in the regulation of muscle and adipose tissue function, but its relationship with body composition remains unclear. OBJECTIVES: This study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) concentration, its subspecies, and body composition parameters and related phenotypes in Korean adults aged ≥20 years. METHODS: This cross-sectional study included 2612 eligible participants from the Korea National Health and Nutrition Examination Survey 2022-2023, and data on body composition parameters and serum 25(OH)D levels were analyzed. Serum 25(OH)D levels and subspecies were determined using liquid chromatography-tandem mass spectrometry. Body composition factors included anthropometric indices, muscle strength, and fat and muscle mass, which were assessed using bioelectrical impedance analysis. RESULTS: After multivariable adjustment, serum concentrations of total 25(OH)D and 25(OH)D₃ were inversely associated with waist circumference, body mass index, and fat mass and positively associated with handgrip strength and lean mass, whereas serum 25(OH)D₂ and 3-epi-25(OH)D₃ levels showed no such associations. Higher 25(OH)D₂ concentrations were positively associated with low muscle strength and the prevalence of sarcopenia. Through non-linear analyses, U-shaped correlations were identified between total 25(OH)D and 25(OH)D₃ levels with low muscle mass, respectively, while a J-shaped correlation was observed between 25(OH)D₂ level and low muscle mass. CONCLUSIONS: Total 25(OH)D and 25(OH)D₃ levels were inversely associated with adiposity and positively associated with muscle strength and lean mass, whereas the 25(OH)D₂ level was linked to low muscle strength and sarcopenia. The U- and J-shaped associations with low muscle mass indicate the complex and differential roles of vitamin D subspecies, warranting further study.

doi.org/10.3390/nu17183013Open accessPubMed 41010538Populations