title: Dietary vitamin A intake and bone health in the elderly: the Rotterdam Study.
abstract: OBJECTIVE
  High vitamin A intake may be associated with a decreased bone mineral density (BMD) and increased risk of fractures. Our objectives were to study whether dietary intake of vitamin A (total, retinol or beta-carotene) is associated with BMD and fracture risk and if associations are modified by body mass index (BMI) and vitamin D.
  
  
  METHODS
  Participants were aged 55 years and older (n=5288) from the Rotterdam Study, a population-based prospective cohort. Baseline vitamin A and D intake was measured by a food frequency questionnaire. BMD was measured by dual-energy X-ray absorptiometry at four visits between baseline (1989-1993) and 2004. Serum vitamin D was assessed in a subgroup (n=3161). Fracture incidence data were derived from medical records with a mean follow-up time of 13.9 years.
  
  
  RESULTS
  Median intake of vitamin A ranged from 684 retinol equivalents (REs)/day (quintile 1) to 2000 REs/day (quintile 5). After adjustment for confounders related to lifestyle and socioeconomic status, BMD was significantly higher in subjects in the highest quintile of total vitamin A (mean difference in BMD (95% confidence interval (CI))=11.53 (0.37-22.7) mg/cm(2)) and retinol intake (mean difference in BMD (95% CI)=12.57 (1.10-24.05) mg/cm(2)) than in the middle quintile. Additional adjustment for BMI diluted these associations. Fracture risk was reduced in these subjects. Significant interaction was present between intake of retinol and overweight (BMI >25 kg/m(2)) in relation to fractures (P for interaction =0.05), but not BMD. Stratified analysis showed that these favourable associations with fracture risk were only present in overweight subjects (BMI >25 kg/m(2)). No effect modification by vitamin D intake or serum levels was observed.
  
  
  CONCLUSIONS
  Our results suggest a plausible favourable relation between high vitamin A intake from the diet and fracture risk in overweight subjects, whereas the association between vitamin A and BMD is mainly explained by BMI.
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.|Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: E A L
authors.initials: EA
authors.lastname: de Jonge
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.|Department of Global Public Health, Leiden University College, The Hague, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Kiefte-de Jong
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Campos-Obando
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Booij
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: O H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.|Erasmus MC, Department of Epidemiology, Rotterdam, The Netherlands.
authors.forename: A G
authors.initials: AG
authors.lastname: Uitterlinden
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Rivadeneira
authors.affiliation: Erasmus MC, Department of Internal Medicine, Rotterdam, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: Zillikens
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D009752:Nutritional Status; D011446:Prospective Studies; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014801:Vitamin A / Q000008:administration & dosage* / Q000097:blood; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood
chemical_list: D014801:Vitamin A; D014807:Vitamin D