title: Circulating 25-hydroxyvitamin D and physical performance in older adults: a nationwide study in Taiwan.
abstract: A previous study indicated that 31% of the elderly in Taiwan have a vitamin D deficiency. Vitamin D adequacy has been associated with physical performance in the elderly.
  
  
  
  The first aim of the current study was to identify the determinants for vitamin D deficiency. The second aim was to evaluate the association between vitamin D status and physical performance.
  
  
  
  A total of 5664 community-dwelling participants aged ≥55 y were recruited since 2008. Plasma total 25-hydroxyvitamin D concentrations were originally determined by ELISA and calibrated to a chemiluminescence measurement. Physical performance was assessed by handgrip strength, the Short Physical Performance Battery, timed up and go, a 6-min walk test, and single-leg stands. Multiple linear regression and logistic regression were used to estimate the cross-sectional associations.
  
  
  
  Vitamin D inadequacy (<50 nmol/L) was related to higher education (P-trend < 0.01), body mass index [(BMI; in kg/m2) ORs (95% CIs) for ≥30 compared with 18.5 to <25 were 1.78 (1.14, 2.78) for men and 1.53 (1.11, 2.11) for women], and vegetable intake [fourth compared with first quartile, 1.58 (1.15, 2.18) for men and 2.38 (1.82, 3.12) for women]. Higher intakes of fish [fourth compared with first quartile, 0.44 (0.33, 0.59) for men and 0.27 (0.21, 0.36) for women] and milk [fourth compared with first quartile, 0.46 (0.31, 0.69) for men and 0.69 (0.49, 0.95) for women] were associated with lower risk of vitamin D inadequacy. Few subjects had 25-hydroxyvitamin D concentrations <30 nmol/L. Above that concentration, there was no dose-effect relation with physical performance except for single-leg stands.
  
  
  
  The factors associated with vitamin D inadequacy in Taiwan were higher education, higher BMI, and lower fish and milk intakes. No dose-effect relation existed between vitamin D concentration and physical performance except for single-leg stands. This study was registered at www.clinicaltrials.gov as NCT02677831.
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan; scchuang@nhri.org.tw hsiung@nhri.org.tw.
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Chuang
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Tseng
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors.forename: I-Chien
authors.initials: IC
authors.lastname: Wu
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Hsu
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan.
authors.forename: Hsing-Yi
authors.initials: HY
authors.lastname: Chang
authors.affiliation: Institute for Translational Genomics and Biomedical Sciences, Los Angeles Biomedical Research Institute, Harbor-University of California, Los Angeles Medical Center, Torrance, CA.
authors.forename: Yii-Der Ida
authors.initials: YI
authors.lastname: Chen
authors.affiliation: Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA; and.
authors.forename: Marion M
authors.initials: MM
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.affiliation: Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli, Taiwan; scchuang@nhri.org.tw hsiung@nhri.org.tw.
authors.forename: Chao Agnes
authors.initials: CA
authors.lastname: Hsiung
mesh_terms: D000368:Aged; D015992:Body Mass Index; D002138:Calibration; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004032:Diet; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D005638:Fruit; D018737:Hand Strength; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D011788:Quality of Life; D012621:Seasons; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology; D014675:Vegetables; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: HALST; epidemiology; lifestyle factors; physical performance; vitamin D