title: Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status.
abstract: Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency.
  
  
  BACKGROUND
  Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans.
  
  
  METHODS
  Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip.
  
  
  RESULTS
  A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years.
  
  
  CONCLUSIONS
  Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Y A
authors.initials: YA
authors.lastname: Kim
authors.forename: K M
authors.initials: KM
authors.lastname: Kim
authors.forename: S
authors.initials: S
authors.lastname: Lim
authors.forename: S H
authors.initials: SH
authors.lastname: Choi
authors.forename: J H
authors.initials: JH
authors.lastname: Moon
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Kim
authors.forename: H C
authors.initials: HC
authors.lastname: Jang
authors.forename: C S
authors.initials: CS
authors.lastname: Shin
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data*; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology; D008875:Middle Aged; D009749:Nutrition Surveys; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D017698:Postmenopause / Q000097:blood / Q000502:physiology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000503:physiopathology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D001205:Ascorbic Acid