"The study results show conclusively that in preterm infants with high rates of vitamin D insufficiency at baseline, supplementation with 800 IU of vitamin D3 per day compared to 400 IU per day reduces vitamin D insufficiency at term equivalent age and at 3 months," Dr. Natarajan said. "There also is a trend toward a decrease in the prevalence of vitamin D insufficiency even in the 400 IU group at 3 months. Therefore, 400 IU per day may be sufficient after 3 months."
Despite significant improvement in serum vitamin D levels in the 800 IU group, higher levels did not result in better bone mineralization at 3 months of age as measured by dual energy X-ray absorptiometry (DEXA). In addition, weight, length and head circumference did not differ significantly between the groups.
Dr. Natarajan also noted that one infant in the 800 IU group had vitamin D levels that were higher than recommended levels at 3 months of age despite the levels at term age being normal. Excess vitamin D for at least one month can cause decreased muscle tone, decreased appetite, irritability and constipation, among other problems. The infant did not experience any major effects.
"The incidence of vitamin D excess in the 800 IU group may indicate the need for monitoring vitamin D levels in infants on vitamin D supplementation, but we need larger studies to answer this," he said. "Similarly, larger studies with longer duration of follow-up may be needed to find out any meaningful difference in clinical outcomes such as bone mineralization."
|Contact: Debbie Jacobson|
American Academy of Pediatrics