title: The utility of neonatal dried blood spots for the assessment of neonatal vitamin D status.
abstract: Evidence suggests that low concentrations of 25-hydroxyvitamin D(3) (25OHD3) during gestation may be associated with a range of adverse health outcomes in later life. Retrospective estimation of perinatal vitamin D status using questionnaires is extremely unreliable and stored serum samples are rarely available. We aimed to validate the use of dried blood spots (DBS) to estimate perinatal vitamin D status and to determine whether inter-group differences in cord serum 25OHD3 are reflected in DBS. We examined 25OHD3 in 4-year-old frozen cord sera and matched DBS from neonates born at a hospital in Melbourne, Australia (n = 100). We examined the correlation between these values and also investigated whether the expected seasonal (winter/spring vs. summer/autumn) difference in serum 25OHD3 was reflected in DBS values. 25OHD3 was assayed in triplicate using tandem mass spectroscopy in both a 3 microL sample of cord serum and in matched 3 mm punches from archived DBS. 25OHD3 concentrations in neonatal cord serum and DBS were highly correlated (r = 0.85, P < 0.0001). As expected, serum 25OHD3 concentrations were higher in neonates born in summer/autumn (December to March) vs. winter/spring (April to November) (median 46.6 vs. 23.7 nmol/L, P < 0.0001). A comparable difference was seen in DBS values (17.8 vs. 10.5 nmol/L, P = 0.0001). Archived DBS samples provided a valid measure of perinatal vitamin D status and identified inter-seasonal differences in perinatal 25OHD3 concentrations. They could be used for case-control studies investigating the association between perinatal vitamin D status and later health outcomes.
authors.affiliation: Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland, Australia. eyles@uq.edu.au
authors.forename: Darryl W
authors.initials: DW
authors.lastname: Eyles
authors.forename: Ruth
authors.initials: R
authors.lastname: Morley
authors.forename: Cameron
authors.initials: C
authors.lastname: Anderson
authors.forename: Pauline
authors.initials: P
authors.lastname: Ko
authors.forename: Thomas
authors.initials: T
authors.lastname: Burne
authors.forename: Michael
authors.initials: M
authors.lastname: Permezel
authors.forename: Preben B
authors.initials: PB
authors.lastname: Mortensen
authors.forename: Bent
authors.initials: B
authors.lastname: Nørgaard-Pedersen
authors.forename: David M
authors.initials: DM
authors.lastname: Hougaard
authors.forename: John J
authors.initials: JJ
authors.lastname: McGrath
mesh_terms: D002853:Chromatography, Liquid; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008403:Mass Screening / Q000379:methods; D013058:Mass Spectrometry; D011247:Pregnancy; D012621:Seasons; D012680:Sensitivity and Specificity; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D