title: Association between night-shift work and serum 25-hydroxyvitamin D levels in Japanese male indoor workers: a cross-sectional study.
abstract: Although low vitamin D status resulting from night work is a suspected cause of various health disorders, few studies have investigated the association between night-shift work and vitamin D status. Here, we examined serum 25-hydroxyvitamin D (25OHD) levels in 19 Japanese indoor workers, including night-shift workers, in blood samples collected at the annual medical checkup (late July) in a metal tool factory. Analyses were finally restricted to 14 male workers (33-59 yr) in 3 groups: fixed daytime work (n=6), and rotating shift work with (n=4) and without (n=4) night shifts. No significant differences in serum 25OHD levels were observed among the three groups (p=0.98, Kruskal-Wallis test). One to two participants in each group had 25OHD levels lower than the 20 ng/ml reference value for vitamin D deficiency even in summer. These results clearly indicate the need for large-scale studies to test the hypothesis that night-shift work is associated with lower 25OHD levels.
authors.affiliation: National Institute of Occupational Safety and Health, Kawasaki, Japan. itoh-hiroaki@umin.ac.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Itoh
authors.forename: Zuquan
authors.initials: Z
authors.lastname: Weng
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Saito
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Kunio
authors.initials: K
authors.lastname: Nakayama
authors.forename: Masako
authors.initials: M
authors.lastname: Hasegawa-Ohira
authors.forename: Kanehisa
authors.initials: K
authors.lastname: Morimoto
authors.forename: Syou
authors.initials: S
authors.lastname: Maki
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010561:Personnel Staffing and Scheduling; D020178:Sleep Disorders, Circadian Rhythm / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D