Vitamin D status and its predictors among pre-school children in Adelaide.
OBJECTIVE
To assess vitamin D status and its predictors in a representative population sample of pre-school children in Adelaide (latitude of 35°S).


METHODS
Cross-sectional survey of children aged between 1 and 5 years from areas of low, medium and high socio-economic status as identified from the 2001 Census data, Australian Bureau of Statistics. Children were recruited between September 2005 and July 2007 using a door knocking protocol based on a stratified sampling method to obtain a representative sample of this age group. Serum 25-hydroxyvitamin D (25(OH)D) was determined using a radio-immunoassay kit. Vitamin D deficiency was defined as serum 25(OH)D) <30 nmol/L and insufficiency defined as serum 25(OH)D ≥30 and <50 nmol/L according to the Institute of Medicine.


RESULTS
Fifty-two per cent of eligible children took part in the study. Mean (standard deviation) serum 25(OH)D was 73 (26) nmol/L (n = 221). The prevalence of vitamin D deficiency and insufficiency was 4% and 16%, respectively, with the prevalence being higher in winter (8% and 22%, respectively). Season of the year of blood collection and mother being born in Australia were significant predictors of serum 25(OH)D concentration, but age, sex, socio-economic status, BMI category or dietary supplement use were not related to vitamin D status.


CONCLUSIONS
Vitamin D status of this representative sample of pre-school children in Australia is adequate, and the prevalence of vitamin D deficiency is low based on the Institute of Medicine criteria.
Women's & Children' Health Research Institute (WCHRI), Adelaide, South Australia, Australia.|School of Agriculture, Food & Wine, University of Adelaide, Adelaide, South Australia, Australia.
Shao J
SJ
Zhou
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Murray
M
Skeaff
Women's & Children' Health Research Institute (WCHRI), Adelaide, South Australia, Australia.|School of Paediatrics & Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia.|South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.
Maria
M
Makrides
School of Agriculture, Food & Wine, University of Adelaide, Adelaide, South Australia, Australia.
Robert
R
Gibson
D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D011863:Radioimmunoassay; D012307:Risk Factors; D013021:South Australia / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
D014807:Vitamin D; C104450:25-hydroxyvitamin D
25(OH)D; deficiency; pre-school child; predictor; vitamin D status