title: Gender-dependent skeletal effects of vitamin D deficiency in a younger generation.
abstract: BACKGROUND
  The major health threats caused by vitamin D deficiency in the young generation have not been fully elucidated.
  
  
  OBJECTIVE
  The aim of this study was to investigate skeletal and nonskeletal effects of vitamin D deficiency and to study the optimal level of serum 25-hydroxyvitamin D [25(OH)D] in young people.
  
  
  METHODS
  The Fourth Korea National Health and Nutrition Examination Surveys (KNHANES IV) was conducted in 2008-2009.
  
  
  METHODS
  A total of 4276 people (1926 men and 2350 women) aged 10-40 yr were selected from 16 administrative districts of South Korea.
  
  
  METHODS
  We measured age-specific changes in bone mineral density (BMD) according to serum 25(OH)D.
  
  
  RESULTS
  Serum 25(OH)D was less than 25 nmol/liter in 18.8% of participants, 25 to less than 50 nmol/liter in 50.0%, 50 to less than 75 nmol/liter in 27.0%, and 75 nmol/liter or greater in 4.2%. Vitamin D deficiency was more frequent in women than in men. There were gender differences in the skeletal effects of vitamin D deficiency. In men between 10 and 22 yr old, BMD was significantly higher in the vitamin D-sufficient group, and in men between 23 and 40 yr old, a positive correlation between serum 25(OH)D and BMD was observed. However, in women, we could not find significant differences in BMD according to vitamin D status. Vitamin D deficiency in younger generations had no remarkable effects on most nonskeletal parameters or on the prevalence of concomitant diseases except for rheumatoid arthritis.
  
  
  CONCLUSIONS
  Vitamin D plays an essential role in skeletal health of young people. Moreover, the presence of gender-dependent skeletal effects was an important observation of this study. Reassurance of serum 25(OH)D up to 20-30 ng/ml or higher is necessary, especially during the modeling phase in men.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Lim
authors.forename: Kyoung Min
authors.initials: KM
authors.lastname: Kim
authors.forename: Yumie
authors.initials: Y
authors.lastname: Rhee
authors.forename: Sung-Kil
authors.initials: SK
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D001842:Bone and Bones / Q000502:physiology; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009749:Nutrition Surveys / Q000706:statistics & numerical data; D056910:Republic of Korea / Q000453:epidemiology; D012727:Sex Characteristics; D017678:Sex Distribution; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D