Does Vitamin A by Mouth Protect a Premature Baby's Lungs?

What a 2025 review of five studies in 1,715 premature babies found about oral vitamin A and chronic lung disease

Premature babies are often given vitamin A in the hope of protecting their fragile lungs from a chronic lung condition called bronchopulmonary dysplasia. A 2025 review combined five clinical trials involving 1,715 very premature babies and found that vitamin A given by mouth did not meaningfully lower the chance of this lung disease, and did not reduce deaths, serious eye problems, or infections. The one modest benefit was a slightly shorter time on gentle breathing support [1].

Why premature lungs need extra help

When a baby is born many weeks early, almost every organ is unfinished — but the lungs are especially vulnerable. Babies born before 32 weeks of pregnancy are the ones most at risk, and worldwide about 15% of premature births happen this early [2]. Among the tiniest babies, born before 28 weeks, roughly 4 in 10 develop a chronic lung condition called bronchopulmonary dysplasia, often shortened to BPD. BPD means the delicate air sacs and airways have been injured and have not grown normally, so a baby may need extra oxygen or breathing support for weeks or months, and may have breathing troubles well into childhood. One thing that makes BPD tricky to study is that doctors have changed the exact definition of it many times over the years, so older and newer studies do not always measure quite the same thing [3]. Keeping that in mind helps explain why the answer to a seemingly simple question has taken so long [1].

Why vitamin A seemed so promising

Vitamin A is essential for building healthy skin, eyes, and — importantly here — the lining of the lungs and airways. Babies build up their stores of vitamin A during the final weeks of pregnancy, so babies born early simply miss out and start life low on it. That made vitamin A an obvious candidate to help premature lungs, and for years there was good reason for optimism. Decades ago, a large study run by a network of United States hospitals gave premature babies vitamin A as an injection into the muscle several times a week and found a small but real reduction in lung problems [4]. A later summary of the injection studies agreed there was a modest benefit [5]. The catch was practical: the injections hurt, they had to be repeated many times over weeks, and in many parts of the world the injectable form is hard to obtain. Families and clinicians understandably hoped that simply giving the vitamin by mouth — mixed into a baby's feeds — could offer the same protection more gently. This review set out to test whether that hope holds up [1].

What the researchers did

The researchers gathered every high-quality trial they could find, up to May 2024, that compared oral vitamin A against a dummy treatment (a placebo) in babies born before 32 weeks. They combined five trials with 1,715 babies in total. The largest by far, called NeoVitaA, was run in hospitals across Germany and Austria and included 915 babies — more than half of everyone in the review [6]. The others were smaller and came from different parts of the world: Australia [7], India [8], China [9], and the United Kingdom [10]. The trials used quite different doses of vitamin A, which is one reason the researchers were careful about how they combined them. A "trial" here means babies were randomly assigned to receive either vitamin A or the placebo, which is the fairest way to tell whether a treatment truly works.

What they found

The headline result is that oral vitamin A did not significantly reduce moderate-to-severe BPD. To put the numbers in plain terms, the risk of this lung disease in the vitamin A group was about 9% lower than in the placebo group, but that difference was small enough that it could easily be due to chance — so scientists do not count it as a real effect [1]. The same was true for the other outcomes that matter most: vitamin A did not reduce the number of babies who died, did not reduce serious eye disease of prematurity, did not reduce blood infections, and did not shorten the time babies spent on a breathing machine [6][9][8][7]. It also made no difference to bowel or brain complications of prematurity.

There was one genuinely positive finding. Babies who received vitamin A spent, on average, a little over a day less on gentler forms of breathing support such as CPAP or a high-flow nasal cannula — soft airflow delivered through the nose rather than a breathing tube [1]. A day of less breathing support is not nothing, but on its own it is a modest benefit, and it stands almost alone among the results. Interestingly, two of the individual trials did suggest vitamin A helped the lungs, but when all the studies were pooled together, that hint faded away [8][9].

Why the mouth may not work as well as a needle

The most useful clue in this review is about why the oral route may fall short. When the researchers measured vitamin A levels in the babies' blood at four weeks of age, the babies given the oral vitamin did not have meaningfully higher levels than those given placebo [1]. In other words, the vitamin taken by mouth may not have been absorbed well enough to make a difference. A premature baby's gut is immature and struggles to take up fat-soluble vitamins, so much of an oral dose may simply pass through. This fits the bigger picture: the injections, which put the vitamin straight into the body, worked — while the mouth route, tested here, did not. Modern premature babies also tend to be better nourished overall than those in older studies, which may leave less room for an extra supplement to help. Other recent reviews have reached much the same conclusion about the oral route [11][12], while reviews that include the injection studies still show a benefit [13], and earlier oral-route reviews were similarly uncertain [14]. When several independent teams of scientists, looking at the evidence in slightly different ways, keep arriving at the same answer, we can be more confident that the answer is real.

It helps to understand what a study like this can and cannot tell you. Combining many trials into one large analysis is powerful because it brings together far more babies than any single hospital could study, which makes the result more trustworthy. But it also blends together studies that used different doses and were run in different decades and countries, so the "average" answer may hide the possibility that a particular dose, given to a particular group of babies, could still help. That is exactly why the researchers were careful not to say vitamin A is useless — only that, given by mouth in the ways tested so far, it has not been shown to protect the lungs. It is a subtle but important difference, and it is the honest way to describe uncertain science.

What this means for your family, and what comes next

If your baby has not been started on oral vitamin A, or if the team decides to stop it, this is not a case of withholding a proven treatment — the best current evidence simply does not show that the oral form prevents lung disease. Reassuringly, vitamin A is safe: the trials found no increase in vomiting or other harmful effects. Your baby's lung protection comes from the whole package of modern neonatal care, not from any single supplement. Researchers are not giving up on vitamin A; they are asking sharper questions. Would a different formulation that dissolves better be absorbed more effectively? Would a higher dose, or a focus on the very smallest babies, make a difference? And could a version breathed directly into the lungs — an approach now in early testing — recapture the benefit of the old injections without the needles? Until larger, carefully designed studies answer these questions, the sensible course is to rethink giving oral vitamin A routinely just to prevent lung disease, while staying hopeful that a smarter way to use this vitamin may still be found. If you have questions about what your own baby is receiving and why, your neonatal team is the best source of answers — they can explain how the general evidence fits your baby's particular situation, and no question about your child's care is ever too small to ask.

References

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  2. Ohuma EO, Moller AB, Bradley E, et al. National, regional, and global estimates of preterm birth in 2020, with trends from 2010: a systematic analysis. Lancet. 2023;402:1261–1271. doi:10.1016/S0140-6736(23)00878-400878-4) ↩
  3. Ibrahim J, Bhandari V. The definition of bronchopulmonary dysplasia: an evolving dilemma. Pediatric Research. 2018;84:586–588. doi:10.1038/s41390-018-0167-9 ↩
  4. Tyson JE, Wright LL, Oh W, et al. Vitamin A supplementation for extremely-low-birth-weight infants. New England Journal of Medicine. 1999;340:1962–1968. doi:10.1056/NEJM199906243402505 ↩
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  7. Rakshasbhuvankar AA, Simmer K, Patole SK, et al. Enteral vitamin A for reducing severity of bronchopulmonary dysplasia: a randomized trial. Pediatrics. 2021;147:e2020009985. doi:10.1542/peds.2020-009985 ↩
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  9. Sun H, Cheng R, Wang Z. Early vitamin A supplementation improves the outcome of retinopathy of prematurity in extremely preterm infants. Retina. 2020;40:1176–1184. doi:10.1097/IAE.0000000000002543 ↩
  10. Wardle SP, Hughes A, Chen S, et al. Randomised controlled trial of oral vitamin A supplementation in preterm infants to prevent chronic lung disease. Archives of Disease in Childhood — Fetal and Neonatal Edition. 2001;84:F9–F13. doi:10.1136/fn.84.1.F9 ↩
  11. Rakshasbhuvankar AA, Pillow JJ, Simmer KN, et al. Vitamin A supplementation in very-preterm or very-low-birth-weight infants to prevent morbidity and mortality: a systematic review and meta-analysis of randomized trials. American Journal of Clinical Nutrition. 2021;114:2084–2096. doi:10.1093/ajcn/nqab294 ↩
  12. Manapurath RM, Kumar M, Pathak BG, et al. Enteral low-dose vitamin A supplementation in preterm or low birth weight infants to prevent morbidity and mortality: a systematic review and meta-analysis. Pediatrics. 2022;150:e2022057092L. doi:10.1542/peds.2022-057092L ↩
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  14. Phattraprayoon N, Ungtrakul T, Soonklang K, et al. Oral vitamin A supplementation in preterm infants to improve health outcomes: a systematic review and meta-analysis. PLOS ONE. 2022;17:e0265876. doi:10.1371/journal.pone.0265876 ↩