Have you ever known a family who had a premature infant in the Neonatal Intensive Care Unit or NICU? I have. It didn’t turn out well either., The infant was 25 weeks of age. He developed bronchopulmanary dysplasia (BPD), which is caused from giving oxygen to premature infants. If he’d never received oxygen, he would never have developed BPD; Although, If he was never given oxygen, he would not have survived long enough to get BPD. Undeniably, this was a tragic situation, one that occurs far too frequently.
Preterm birth is the most common cause of death among infants worldwide. About 15 million babies are born preterm each year (about 10% of all deliveries). Complications from preterm births resulted in 800,000 worldwide infant deaths in 2015. The chance for the infant to survive when born fewer than 23 weeks is close to zero, while at 23 weeks it is about 15%, 24 weeks 55% and 25 weeks about 80%. Just 60 years ago, virtually all infants below 25 weeks died.
Bronchopulmonary dysplasia (BPD) is the most prevalent long-term morbidity among surviving extremely preterm infants. BPD is associated with later risk of reactive airway disease, such as asthma, post neonatal mortality and adverse neurodevelopmental outcomes. BPD affects ~20% of preterm infants and up to 60% of extremely preterm infants who are born before 26 completed weeks of gestation.
Two years ago, Danish researchers conducted a review evaluating the role of vitamin D in lung maturation among preterm infants. They summarized their findings, stating,
“These data support the hypothesis of hypovitaminosis D as a frequent, modifiable risk factor of . . . . bronchopulmonary dysplasia, which should be tested in randomized controlled trials on pregnant women, those with threatening preterm delivery, or in the preterm neonates.”
Lykkedegn S, Sorensen GL, Beck-Nielsen SS, Christesen HT. The impact of vitamin D on fetal and neonatal lung maturation. A systematic review. Am J Physiol Lung Cell Mol Physiol. 2015 Apr 1;308(7):L587-602.
Fast forward two years, and several randomized controlled trials have reported mixed results. A recent meta-analysis showed giving premature infants 1,000 IU/day or 400 IU/day of vitamin D did not decrease the rate of BPD compared to placebo.
Since the majority of lung development occurs during pregnancy, vitamin D is unable to have much effect after the infant is born. Therefore, vitamin D supplementation must occur during pregnancy to promote proper lung development in utero. Indeed, even if every obstetrician put every pregnant woman on 10,000 IU/day at the first prenantal visit (around the end of the first trimester), it would be too little. The lesion in many of the D deficient diseases and conditions of pregnancy, childbirth, infanacy and adulthood, appears to occur in the first trimester.
So how can we deal with this phenomenal public health opportunity? Probably the way the late Professor Robert Heaney concluded, which is the same way neural tube defects, beriberi and pellagra were combated: food fortification. Actually, it should be food fortification, increased sun exposure, physicians recommending vitamin D and patients taking it on their own. I just hope it happens while I’m still alive.