Earlier on in the development of a child, there are many important things happening in the child’s body, including the development of an immune system and the development of lungs before they reach full term. There has been a lot of research conducted recently on how a mother’s diet can influence these two major processes, and there is also a question as to how that nutrition may have an impact on the child’s abilities long after he/she is born, particularly in terms of respiratory type illnesses such as asthma.
A significant amount of research has been conducted on the role of one vitamin, vitamin D₃, in the development of a child’s immune system and lungs prior to birth. Most people are aware that vitamin D is referred to as the “bone vitamin”, but it is much more than that. It is essential for proper development of the immune system and the development of the lungs. With the increase in the number of children with asthma and allergies each year, this raises the question of whether or not mothers who take higher levels of vitamin D during pregnancy will positively influence or help develop their children’s lungs.
Building The Immune System Before Birth
The lungs play an integral part in a child developing his/her immune system. They are where the lymphocyte, the primary cell responsible for fighting infections, begins to develop, and all lymphocyte types have a vitamin D receptor, including T cells, B cells, dendritic cells, and macrophages.
Therefore, if a pregnant woman has an adequate vitamin D level in her bloodstream at the time of pregnancy, it starts the baby’s immune system and lung development prior to actual delivery. Adequate vitamin D levels in the mother will give the child a head start on having good, healthy lungs.
This study shows that maternal vitamin D can help the immune system of the child learn what to attack and what to not attack, regulate inflammation in the body, and improve lung development.
Key Findings
VDAART: Vitamin D Antenatal Asthma Reduction Trial
VDAART was conducted in multiple hospitals across the United States. Pregnant women were assigned to 400 IU (international units) of vitamin D₃ daily or 4,400 IU of vitamin D₃ daily, beginning at mid-pregnancy.
Results of the study indicated that children of mothers in the 4,400 IU/day group had approximately 20% reduced odds of developing asthma or wheezing by 3 years of age compared to children of mothers who were treated with 400 IU/day.
The main finding of this study did not achieve statistical significance; however, there was additional evidence from previous studies concerning a positive relationship between prenatal exposure to Vitamin D and young children. The evidence supports that during pregnancy, use of Vitamin D will significantly reduce the likelihood of developing asthma or persistent wheezing as demonstrated by an odds ratio (OR) of 0.75 (p=0.03).
COPSAC2010 Vitamin D Study
In COPSAC2010, a study conducted in Copenhagen, pregnant women received either 400 IU or 2,800 IU of vitamin D daily during their trial.
In this study, the same finding occurred, in that children whose mothers received more vitamin D₃ had less persistence of wheezing.
In addition to confirming the previous studies, the researchers found a new effect of high maternal vitamin D, in that the higher the mother’s vitamin D₃ level, the greater the change in a metabolic pathway called sphingomyelin metabolism in the infant (p < 0.01), which is associated with decreased wheezing, indicating an underlying biological mechanism to explain the clinical findings.
What Lung Function Studies Say
The VDAART did not just measure lung function at 3 years; they also followed the children to 6 years of age to assess how well their lungs were doing. Overall, the lung function tests revealed the following for children whose mothers received additional vitamin D during pregnancy:
- FVC was statistically significantly greater among children whose mothers received additional vitamin D (β = 0.022 L; P = 0.002).
- FEV₁ was statistically significantly greater among children whose mothers received additional vitamin D (β = 0.018 L; P = 0.008).
- Children born to mothers with added Vitamin D supplementation were found to have a significantly reduced amount of R5 compared to children born to mothers without added vitamin D (β = -0.021 kPa/L/s; P = 0.003).
Conclusively, proper prenatal nutrition has been shown to aid in the development of lung function of a child as well as possibly prevent chronic lung disease for that child in the future.
Why This Matters
Overall, both the VDAART and COPSAC2010 studies have clearly demonstrated that what happens to a pregnant woman will impact a child’s health, most specifically their lungs.
While vitamin D supplementation alone is not sufficient to prevent asthma, having sufficient levels of vitamin D during pregnancy improves immune and lung function in infants. It also decreases the occurrence of wheezing in early childhood.
Conclusion
Lung and immune system development does not occur suddenly at birth they begin to form many months before delivery. Major research studies like VDAART and COPSAC2010 provide evidence that pregnant women who have sufficient vitamin D will have infants at an advantage for being able to breathe more easily, which is associated with fewer wheezy days after birth, and potentially prevent their infant’s immune system from being at risk for dysfunction later on in life.
Prenatal vitamin D will not eliminate asthma entirely, but it appears that prenatal diet, including prenatal vitamin D, may have a greater impact on whether or not an infant will develop asthma than most people are aware of.
References
- Litonjua AA, et al. JAMA. 2016.
- Chawes BL, et al. JAMA Pediatrics. 2016.
- Parr CL, et al. VDAART Follow-Up Analysis.
- Bisgaard H, et al. New England Journal of Medicine. 2016.