366 Follow-Up 25OHD Levels in Preterm Very Low Birth Weight (VLBW) Infants

Abstract

Background and aim: Vitamin D plays an important role in skeletal and non-skeletal health. In preterm VLBW infants, we previously reported a high prevalence (about 80%) of vitamin D insufficiency, defined as a serum 25-hydroxyvitamin D (25OHD) < 50 nmol/L. The aim of this study was to re-assess 25OHD status in those infants who had a level < 50nmol/l, following augmented vitamin D intake.Methods: Preterm or VLBW infants (n=109), who had an initial serum 25OHD level < 50 nmol/L during NICU admission, were re-assessed after advice to ensure vitamin D3 intakes of ≥400IU daily from feeds and supplements.Results: Infants were re-assessed at mean day of life 170 (median 119, range 15-711), or mean postconceptual age (PCA) 53.6wks (median 47.6, range 30.7-127.6). Using a recent classification of vitamin D status[i], we noted that 26 (24%) remained < 50 nmol/L (insufficient); 83 (76%) were ≥50 nmol/L (sufficient); and 40 (37%) were ≥80 nmol/L (desirable). There was a significant correlation between followup 25OHD and PCA (r=0.27;p=0.004), and day of life (r=0.24;p=0.013), but not with ethnicity, gender, gestation at birth, birth weight, or initial 25OHD. A forward multiple regression model identified PCA as the sole predictor of follow-up 25OHD (r2=0.08; p=0.004).Conclusions: About 80% of preterm VLBW infants have insufficient 25OHD levels during early postnatal life; about 25 % remain insufficient at follow-up assessment. A higher level of supplementation is warranted in those infants.