Vitamin D status of very low birth weight infants at birth and the effects of generally recommended supplementation on their vitamin D levels at discharge

Abstract

Purpose: To evaluate vitamin D status in mothers and their very low birth weight infants (VLBW) at birth (umbilical cord blood) and at discharge with currently recommended supplementation of vitamin D.

Methods: Ninety-four infants with birth weight less than 1500 g completed the study. The total daily vitamin D intake was 800–1000 IU. We examined 25-hydroxyvitamin-D [25(OH)D] levels in maternal serum before labor, in cord blood, and in infants’ serum at discharge.

Results: Median (IQR) serum 25(OH)D was 21 (14-36) nmol/l [8 (6–15) ng/ml] in cord blood, and 46 (37–60) nmol/l [18 (15–24) ng/ml] at discharge. Serum 25(OH)D was <50 nmol/L in 71.3% of mothers, in 91.5% of cord blood samples, and in almost 60% of preterm newborns at discharge (after 8 weeks of supplementation). Serum 25(OH)D was <75 nmol/L in 88.3% of mothers, in 97.9% of cord blood samples, and in 91.4% of preterm newborns at discharge.

Conclusions: In our cohort, we found that due to the very high prevalence of 25(OH)D deficiency among mothers, the current generally recommended dose of vitamin D (800–1000 IU per day) for VLBW infants was unable to improve vitamin D levels above the desired 50 or even 75 nmol/L before discharge.

Keywords:

• Infants
• newborn
• preterm
• supplementation
• vitamin D

Acknowledgments

The authors are grateful to Ian McColl MD, PhD for assistance with the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This work was supported by University Hospital Hradec Kralove, Czech Republic project MH CZ – DRO (UHHK, 00179906). The study was supported by the Specific University Research Programme (SVV 260396) from Charles University, Faculty of Medicine in Hradec Kralove.