Vitamin D Levels in Pregnant Women Do Not Affect Neonatal Bone Strength

Abstract

Vitamin D plays a key role in regulating calcium and phosphate metabolism. However, whether maternal vitamin D levels affect fetal bone strength is unclear. This study assessed correlations between maternal 25(OH)D status and neonatal bone strength 25(OH)D levels, these were measured in the maternal and infant cord blood of 81 mother–infant dyads. Bone strength was measured using a quantitative ultrasound (QUS) of tibial bone speed of sound (SOS). Maternal vitamin D intake, medical history and lifestyle were evaluated from questionnaires. Maternal 25(OH)D levels were deficient (50 nmol/L) in 38.3%. The maternal and cord blood 25(OH)D levels correlated (r = 0.85, p p p = 0.002) and in those who took supplemental vitamin D, the bone SOS levels were comparable. In conclusion, maternal vitamin D levels correlate with cord levels but do not affect bone strength or growth parameters.

Keywords

• neonate
• pregnancy
• quantitative ultrasound
• speed of sound
• 25-hydroxy vitamin D
• bone strength