title: Vitamin D status of Māori and non-Māori octogenarians in New Zealand: a Cohort Study (LiLACS NZ).
abstract: OBJECTIVE
  This study assessed vitamin D status and its determinants in a cohort of octogenarians living within New Zealand's Bay of Plenty and Lakes Districts.
  
  
  METHODS
  Serum 25- hydroxyvitamin D [25(OH)D] concentration was measured in 209 Māori (aged 80-90 years) and 357 non-Māori (85 years), along with demographic, lifestyle, supplement use and other health data.
  
  
  RESULTS
  Mean [95% CI] 25(OH)D concentration was 69 [67 to 72] nmol/L, with 15% >100 nmol/L and 6 individuals >150 nmol/L. Concentrations in Māori (59 [55 to 62] 4 nmol/L) were lower than in non-Māori (75 [72 to 78] nmol/L; p<0.001), a difference maintained when adjusted for day-of-year measured. Vitamin D supplementation was reported by 98 participants (18%): including a greater proportion of women (24%) than men (11%; p<0.001) and of non-Māori (24%) than Māori (7%; p<0.001). Of those taking vitamin D, 49% took high oral doses (>=25 μg/day or equivalent) and five individuals took >50 μg/day. Vitamin D supplement use strongly and independently predicted seasonally- adjusted 25(OH)D concentration and was associated with 28 nmol/L higher levels than non-use. Other predictors included Māori ethnicity (10 nmol/L lower concentration than for non-Māori), and female gender (11 nmol/L lower).
  
  
  CONCLUSIONS
  Vitamin D status in New Zealand octogenarians appears higher than previously reported, particularly in non-Māori compared to Māori. Prescribed and non-prescribed oral vitamin D supplementation is prevalent in this group and a strong indicator of vitamin D status.
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand. Email: c.bacon@auckland.ac.nz; c.j.bacon@fitkiwi.co.nz.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Bacon
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Ngaire
authors.initials: N
authors.lastname: Kerse
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Hayman
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Moyes
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Ruth O
authors.initials: RO
authors.lastname: Teh
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Mere
authors.initials: M
authors.lastname: Kepa
authors.affiliation: Department of Statistics, University of Auckland, New Zealand.
authors.forename: Avinesh
authors.initials: A
authors.lastname: Pillai
authors.affiliation: Department of General Practice and Primary Health Care, Faculty of Medical and Health Sciences, University of Auckland, New Zealand.
authors.forename: Lorna
authors.initials: L
authors.lastname: Dyall
mesh_terms: D000369:Aged, 80 and over; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D009752:Nutritional Status; D012621:Seasons; D012737:Sex Factors; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D