A study recently published by Srinivasan et al. looked at 25(OH)D serum levels of 80 preterm infants (gestation less than 34 weeks). Objectives of the study were to determine the vitamin D levels in the cord blood of these infants, randomly assign each infant to either 400 IU daily or 800-1000 IU daily supplementation, and then to correlate the serum vitamin D levels to neonatal morbidity and outcome of sepsis, retinopathy of prematurity (ROP), and delayed retinal maturation.

Within this group of premature infants:

  • Late onset sepsis was present in 48 infants (60%)
  • Those who developed sepsis had 25(OH)D levels of 14±6 ng/ml compared to infants who did not develop sepsis, 31±10 ng/ml (P <0.01)
  • ROP was present in 30 infants (37.5%)
  • Those who developed ROP had 25(OH)D levels of 16±11 ng/ml compared to infants who did not develop ROP, 34±18 ng/ml (P <0.03)
  • Retinal maturation was delayed beyond 40 weeks in 34 infants (42.5%)
  • Those whose retinal maturation was delayed beyond 40 weeks had 25(OH)D levels postnatally of 12±6 ng/ml, compared to infants who did not have delayed retinal maturation, 26±7 ng/ml (P <0.02)

The paper concludes that the American Academy of Pediatrics’ guidelines for supplementation in infants of 400 IU is insufficient, and most infants require 800 – 1000 IU vitamin D soon after birth to maintain physiological vitamin D levels of ≥ 30 ng/ml, especially if they are exclusively breast fed.