Environmental and individual predictors of 25-hydroxyvitamin D concentrations in Denmark measured from neonatal dried blood spots: the D-tect study

Abstract

Environmental factors such as sunshine hours, temperature and UV radiation (UVR) are known to influence seasonal fluctuations in vitamin D concentrations. However, currently there is poor understanding regarding the environmental factors or individual characteristics that best predict neonatal 25-hydroxyvitamin D (25(OH)D) concentrations. The aims of this study were to (1) identify environmental and individual determinants of 25(OH)D concentrations in newborns and (2) investigate whether environmental factors and individual characteristics could be used as proxy measures for neonatal 25(OH)D concentrations. 25-Hydroxyvitamin D3 (25(OH)D3) was measured from neonatal dried blood spots (DBS) of 1182 individuals born between 1993 and 2002. Monthly aggregated data on daily number of sunshine hours, temperature and UVR, available from 1993, were retrieved from the Danish Meteorological Institute. The individual predictors were obtained from the Danish National Birth register, and Statistics Denmark. The optimal model to predict 25(OH)D3 concentrations from neonatal DBS was the one including the following variables: UVR, temperature, maternal education, maternal smoking during pregnancy, gestational age at birth and parity. This model explained 30 % of the variation of 25(OH)D3 in the neonatal DBS. Ambient UVR in the month before the birth month was the best single-item predictor of neonatal 25(OH)D3, accounting for 24 % of its variance. Although this prediction model cannot substitute for actual blood measurements, it might prove useful in cohort studies ranking individuals in groups according to 25(OH)D3 status.

Failure of national antenatal vitamin D supplementation programme puts dark skinned infants at highest risk: A newborn bloodspot screening study

“…[35] The well-recognised seasonal, [35,36] and ethnic, [37,38] variations in 25OHD concentrations were confirmed. Most importantly, the plasma equivalent 25OHD concentrations derived from DBS reported here are comparable to other reports from DBS, [28,39] and also cord serum. [29,40] These agreements across studies confirm the utility of blood spot assays in accurately determining the vitamin D status of the newborn.…”

“…Very few studies have assessed 25OHD on DBS obtained from NBS. [28][29][30] To our best knowledge, our study is the first to ascertain prevalence of neonatal vitamin D deficiency in non-archived DBS, eliminating the concern of 25OHD degradation with prolonged storage. [31] The potential limitation is the lack of data on maternal and early infant supplementation, especially since compliance with national policy on vitamin D supplementation is known to be poor.…”

Sensitive and Robust LC-MS/MS Assay to Quantify 25-Hydroxyvitamin D in Leftover Protein Extract from Dried Blood Spots

“…The standards, instrumentation, chromatographic condition (Table S1), tandem mass spectrometry detection (Figure S2) and quantification of the vitamin D metabolites were consistent with our previous methods for detecting vitamin D metabolites in DBS [4]. Full details of these steps are provided in the Supplement.…”

“…In summary, the %CV for 25OHD 3 was in the range of 0.5-7.7% and the %CV for the total full-blood concentrations ranged from 1.1-8.4%, while %CV for 25OHD 2 ranged between 3.9-17.1%. The suboptimal %CV for 25OHD 2 mainly reflects the low concentration of endogenous 25OHD 2 in the samples, which has been observed in previous DBS-related studies [4,6].…”

Comprehensive Analysis of Seasonal and Geographical Variation in UVB Radiation Relevant for Vitamin D Production in Europe

“…Understanding the ambient UVB dose—and thus the background dermal vitamin D production—at various locations and seasons, is key to formulating designer guidelines aimed at eradicating vitamin D deficiency, via oral vitamin D supplementation, food fortification or artificial light supplementation [ 13 ]. Moreover, as the broader benefits of sunshine for human health are being recognized, detailed understanding of solar radiation is critical for developing tailored sun exposure recommendations, with a view of maximizing benefit and minimizing harm.…”