biostudies-literatureUnknown186(4)Kim Y<h4>Objective</h4>Despite the known benefit of vitamin D in reducing sarcopenia risk in older adults, its effect against muscle loss in the young population is unknown. We aimed to examine the association of serum 25-hydroxy vitamin D [25(OH)D] level and its changes over time with the risk of incident low muscle mass (LMM) in young and middle-aged adults.<h4>Design</h4>This study is a cohort study.<h4>Methods</h4>The study included Korean adults (median age: 36.9 years) without LMM at baseline followed up for a median of 3.9 years (maximum: 7.3 years). LMM was defined as the appendicular skeletal muscle (ASM) mass by body weight (ASM/weight) of 1 s.d. below the sex-specific mean for the young reference group. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95%European journal of endocrinology477-487https://www.ebi.ac.uk/biostudies/studies/S-EPMC8942330biostudies-literatureSerum 25-hydroxy vitamin D and the risk of low muscle mass in young and middle-aged Korean adults.PMC8942330Kwon MJWild SHCho IYKim YByrne CDChang YRyu SfalseSerum 25-hydroxy vitamin D and the risk of low muscle mass in young and middle-aged Korean adults.<h4>Objective</h4>Despite the known benefit of vitamin D in reducing sarcopenia risk in older adults, its effect against muscle loss in the young population is unknown. We aimed to examine the association of serum 25-hydroxy vitamin D [25(OH)D] level and its changes over time with the risk of incident low muscle mass (LMM) in young and middle-aged adults.<h4>Design</h4>This study is a cohort study.<h4>Methods</h4>The study included Korean adults (median age: 36.9 years) without LMM at baseline followed up for a median of 3.9 years (maximum: 7.3 years). LMM was defined as the appendicular skeletal muscle (ASM) mass by body weight (ASM/weight) of 1 s.d. below the sex-specific mean for the young reference group. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95%2022-01-01T00:00:00Z2022 Mar2025-04-19T21:47:37.503Z2025-04-19T21:47:37.503ZS-EPMC89423303514751110.1530/EJE-21-1229