Serum 25 Hydroxy Vitamin D Levels in Very Low Birth Weight Infants Receiving Oral Vitamin D Supplementation.

Abstract

Vitamin D supplementation in preterm infants has been recommended by American Academy of Pediatrics (AAP); however, its efficacy and safety has not been well studied. To study 25-hydroxy vitamin D (25OHD) levels as a marker of vitamin D status of very low birth weight infants while on vitamin D supplementation during neonatal intensive care unit hospitalization. Retrospective study of preterm infants with birth weight <1500 g admitted to our unit from January 2013 to December 2015 who were on oral vitamin D3 400 IU supplementation. Serum 25OHD level were checked at 4, 8, and 12 weeks of age or before discharge and the levels were stratified as deficient <20 ng/mL, insufficient 20 to 29 ng/mL, normal 30 to 60 ng/mL, high 61 to 100 ng/mL and very high >100 ng/mL. A total of 301 infants were enrolled, 186 very low birth weight (VLBW; 1000-1499 g) infants and 115 extremely low birth weight (ELBW; <1000 g) infants. Approximately 80% of both VLBWs and ELBWs had deficient or insufficient 25OHD levels at 4 weeks of age. On oral vitamin D supplementation, VLBW infants increased their 25OHD levels significantly by 8 and 12 weeks of age, whereas ELBW infants lagged behind at 8 weeks and increased their 25OHD levels by 12 weeks of age. Eighty percent of ELBW and VLBW infants have either deficient or insufficient vitamin D status at 4 weeks of age. Vitamin D supplementation helps in improving the vitamin D levels, VLBW infants significantly more than ELBW infants. AAP recommendation appears to be safe; however, if using higher supplement dosing, 25OHD level should be monitored to avoid high and very high vitamin D levels.