A recent study published in the journal Early Human Development discovered that 1,000 IU of vitamin D3 was more effective at increasing preterm infants vitamin D levels to optimal status than 800 IU or 400 IU.
Researchers included a total of 121 stable preterm infants that were born between 24 and 32 weeks gestation. The infants were randomly assigned to receive either 400, 800 or 1,000 IU vitamin D3 per day. Serum blood draws at baseline and at the end of the study provided the researchers with data on vitamin D status, calcium status and parathyroid hormone concentrations. Supplementation began directly after the baseline blood draw.
All the infants were administered their assigned dose until they reached 36 weeks post-menstrual age (PMA). This means that they would begin supplementation near the time they were born, up until they reached what would have been 36 weeks in the womb, if they were born within normal gestational age.
This is what the researchers found:
- A total of 72% of the infants were considered vitamin D deficient ( Average vitamin D levels at 36 weeks PMA were significantly higher in the 800 IU (40 ± 21.4) and 1000 IU groups (43 ± 18.9) compared to the 400 IU group (29.4 ± 13) (p = 0.014 and p ≤ 0.001, respectively).
- There was no significant difference in vitamin D status between the 800 IU group and the 1,000 IU group.
- There was a significantly lower rate of vitamin D deficiency in the 1,000 IU group compared to the 400 IU group (p = 0.007).
- There was a similar trend of vitamin D deficiency in the 800 IU group compared to the 400 IU group, but this was not statistically significant.
The researchers concluded:
“Enteral supplementation of 1000 IU/d vitamin D is well tolerated and effective at increasing vitamin D concentrations and decreasing prevalence of vitamin D deficiency by 36 weeks corrected age in stable preterm infants.”
Bozkurt, O. et al. Multi-dose vitamin d supplementation in stable very preterm infants: Prospective randomized trial response to three different vitamin D supplementation doses . Early Human Development, 2017.