Seasonal variation in maternal and umbilical cord 25(OH) vitamin D and their associations with neonatal adiposity.
METHODS
Neonatal body fat is an important indicator of foetal energy supply and growth with potential importance for long-term health. In this study, we wanted to explore seasonal variation of 25-hydroxy-vitamin D (25(OH)D) in maternal and umbilical cord plasma (UCP) to examine whether maternal and foetal 25(OH)D levels were associated with maternal BMI and neonatal fat mass (FM), and to explore the relationship among maternal and neonatal 25(OH)D levels, maternal glucose/insulin levels and UCP C-peptide.


METHODS
An observational, prospective study of determinants of foetal growth and birth weight in healthy pregnant women. Total body composition in 202 newborns was measured by dual-energy X-ray absorptiometry. Circulating levels of biomarkers were assessed in mothers at gestational weeks 14-16 and 30-32 and UCP.


RESULTS
The mean 25(OH)D concentration in UCP was significantly lower than in maternal circulation (31 vs 45 nmol/l, P<0.001). Maternal and UCP 25(OH)D levels varied significantly with season. No significant association between maternal BMI (weeks 14-16) and UCP 25(OH)D concentration was found. We found a strong positive association between maternal 25(OH)D and UCP 25(OH)D (P<0.001). There was no significant linear association between maternal BMI (weeks 14-16) and maternal 25(OH)D. We found no association between maternal 25(OH)D levels and glucose/insulin levels, nor with maternal or UCP 25(OH)D on UCP C-peptide levels. Finally, neonatal total body FM was positively associated with UCP 25(OH)D, P=0.02.


CONCLUSIONS
We demonstrated seasonal variation in maternal and neonatal 25(OH)D levels at northern latitudes. UCP, but not maternal, 25(OH)D was a significant predictor of neonatal total FM. Maternal BMI and metabolic parameters such as glucose, insulin and UCP C-peptide levels were not associated with 25(OH)D in mothers or offspring.
Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital Rikshospitalet, PO Box 4950 Nydalen, 0424 Oslo, Norway.
Kristin
K
Godang
Kathrine Frey
KF
Frøslie
Tore
T
Henriksen
Elisabeth
E
Qvigstad
Jens
J
Bollerslev
D015502:Absorptiometry, Photon; D050154:Adiposity; D000328:Adult; D001786:Blood Glucose; D001823:Body Composition; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D047109:Fetal Development; D006801:Humans; D007231:Infant, Newborn; D007328:Insulin / Q000097:blood; D016014:Linear Models; D008297:Male; D009664:Norway; D009765:Obesity / Q000097:blood; D011247:Pregnancy; D011446:Prospective Studies; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D014807:Vitamin D; C104450:25-hydroxyvitamin D