title: Serum 25-hydroxyvitamin D concentration and its determinants in the very old: the Newcastle 85+ Study.
abstract: CONCLUSIONS
  Data on vitamin D status in very old adults are lacking. The aim of this study was to assess 25-hydroxyvitamin D [25(OH)D] concentrations and its predictors in 775 adults aged 85 years old living in North-East England. Low 25(OH)D was alarmingly high during winter/spring months, but its biological significance is unknown.
  
  
  BACKGROUND
  Despite recent concerns about the high prevalence of vitamin D deficiency in much of the British adult and paediatric population, there is a dearth of data on vitamin D status and its predictors in very old adults. The objective of the present study was to describe vitamin D status and its associated factors in a broadly representative sample of very old men and women aged 85 years living in the North East of England (55° N).
  
  
  METHODS
  Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were analysed in 775 participants in the baseline phase of the Newcastle 85+ cohort study. Season of blood sampling, dietary, health, lifestyle and anthropometric data were collected and included as potential predictors of vitamin D status in ordinal regression models.
  
  
  RESULTS
  Median serum 25(OH)D concentrations were 27, 45, 43 and 33 nmol/L during spring, summer, autumn and winter, respectively. The prevalence of vitamin D deficiency according to North American Institute of Medicine guidelines [serum 25(OH)D <30 nmol/L] varied significantly with season with the highest prevalence observed in spring (51%) and the lowest prevalence observed in autumn (23%; P < 0.001). Reported median (inter-quartile range) dietary intakes of vitamin D were very low at 2.9 (1.2-3.3) μg/day. In multivariate ordinal regression models, non-users of either prescribed or non-prescribed vitamin D preparations and winter and spring blood sampling were associated with lower 25(OH)D concentrations. Dietary vitamin D intake, disability score and disease count were not independently associated with vitamin D status in the cohort.
  
  
  CONCLUSIONS
  There is an alarming high prevalence of vitamin D deficiency (<30 nmol/L) in 85-year-olds living in North East England at all times of the year but particularly during winter and spring. Use of vitamin D containing preparations (both supplements and medications) appeared to be the strongest predictor of 25(OH)D concentrations in these very old adults.
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK. Tom.Hill@ncl.ac.uk.|School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. Tom.Hill@ncl.ac.uk.|Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. Tom.Hill@ncl.ac.uk.
authors.forename: T R
authors.initials: TR
authors.lastname: Hill
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Institute for Health and Society, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: A
authors.initials: A
authors.lastname: Granic
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Institute for Health and Society, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: K
authors.initials: K
authors.lastname: Davies
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: J
authors.initials: J
authors.lastname: Collerton
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: C
authors.initials: C
authors.lastname: Martin-Ruiz
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.|Institute for Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: M
authors.initials: M
authors.lastname: Siervo
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.|Institute for Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: J C
authors.initials: JC
authors.lastname: Mathers
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.|Institute for Health and Society, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Adamson
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Institute for Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Francis
authors.affiliation: Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK.
authors.forename: S H
authors.initials: SH
authors.lastname: Pearce
authors.affiliation: Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK.
authors.forename: S
authors.initials: S
authors.lastname: Razvi
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: T B L
authors.initials: TBL
authors.lastname: Kirkwood
authors.affiliation: Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.|Institute for Health and Society, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: C
authors.initials: C
authors.lastname: Jagger
mesh_terms: D000369:Aged, 80 and over; D001800:Blood Specimen Collection / Q000379:methods; D002136:Calcium, Dietary / Q000008:administration & dosage; D004032:Diet / Q000706:statistics & numerical data; D019587:Dietary Supplements; D004739:England / Q000453:epidemiology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D012111:Residence Characteristics; D012307:Risk Factors; D012621:Seasons; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology* / Q000209:etiology
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Aged 80 and over; Determinants; Newcastle 85+ cohort study; Serum 25-hydroxyvitamin D