title: Predictors of vitamin D status in New Zealand preschool children.
abstract: Vitamin D deficiency has adverse health effects in young children. Our aims were to determine predictors of vitamin D status and then to use these factors to develop a practical tool to predict low 25(OH)D concentrations in preschool New Zealand children. A cross-sectional sample of 1329 children aged 2 to <5 years were enrolled from throughout New Zealand in late-winter to spring 2012. 25-Hydroxyvitamin D (25(OH)D) was measured on dried blood spot (DBS) samples collected using finger-prick sampling. Caregivers completed a questionnaire. Mean (SD) DBS 25(OH)D concentration was 52(19)nmol/L. 25(OH)D < 25 nmol/L was present in 86(7%), 25(OH)D < 50 nmol/L in 642(48%), 25(OH)D 50- < 75 nmol/L in 541(41%) and 25(OH)D > 75 nmol/L in 146(11%) of children. Factors independently associated with the risk of 25(OH)D < 25 nmol/L were female gender (OR 1.92,95%CI 1.17-3.14), other non-European ethnicities (not including Māori or Pacific) (3.51,1.89-6.50), had olive-dark skin colour (4.52,2.22-9.16), did not take vitamin D supplements (2.56,1.06-6.18), had mothers with less than secondary-school qualifications (5.00,2.44-10.21) and lived in more deprived households (1.27,1.06-1.53). Children who drank toddler milk (vitamin D fortified cow's milk formula marketed to young children) had a zero risk of 25(OH)D < 25 nmol/L. The predictive tool identified children at risk of 25(OH)D < 25 nmol/L with sensitivity 42%, specificity 97% and ROC area-under-curve 0.76(95%CI 0.67-0.86, p < 0.001). Predictors of low vitamin D status were consistent with those identified in previous studies of New Zealand children. The tool had insufficient predictive ability for use in clinical situations, and suggests a need to promote safe, inexpensive testing to determine vitamin D status in preschool children.
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand.
authors.forename: C T
authors.initials: CT
authors.lastname: Cairncross
authors.affiliation: CSIRO Food and Nutrition, Adelaide, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Stonehouse
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand.
authors.forename: C A
authors.initials: CA
authors.lastname: Conlon
authors.affiliation: Department of Paediatrics: Child and Youth Health, University of Auckland, Auckland, New Zealand.|General Paediatrics, Starship Children's Hospital, Auckland, New Zealand.
authors.forename: C C
authors.initials: CC
authors.lastname: Grant
authors.affiliation: Institute of Natural and Mathematical Sciences, Massey University, Auckland, New Zealand.
authors.forename: B
authors.initials: B
authors.lastname: McDonald
authors.affiliation: Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
authors.forename: L A
authors.identifier: 0000-0002-2276-6205
authors.initials: LA
authors.lastname: Houghton
authors.affiliation: Queensland Brain Institute, University of Queensland, Brisbane, Australia.|Queensland Centre for Mental Health Research, Brisbane, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Eyles
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Camargo
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand.
authors.forename: J
authors.initials: J
authors.lastname: Coad
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand.
authors.forename: P R
authors.initials: PR
authors.lastname: von Hurst
mesh_terms: D000818:Animals; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008297:Male; D008892:Milk / Q000737:chemistry; D009520:New Zealand / Q000453:epidemiology; D009752:Nutritional Status; D012574:Schools; D012621:Seasons; D012880:Skin Pigmentation; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology*
chemical_list: D014807:Vitamin D
keywords: New Zealand; child; questionnaire; status; vitamin D deficiency