Vitamin E Deficiency in Mothers Linked To High Risk of Pediatric Asthma

Physicians have long cautioned pregnant women to monitor their vitamin and mineral intake. A recent study presented at the American Academy of Allergy, Asthma, & Immunology (AAAAI) 2017 meeting suggested that children born to mothers with low levels of vitamin E isoform alpha-tocopherol have a higher risk of developing asthma and are more likely to wheeze.

Although it’s too early to confirm a causal relationship, further research could potentially lead to new public health measures.

The specific genetic and environmental causes of asthma development are still unclear; however, researchers from Vanderbilt University and Northwestern University had previously seen the “effects of different components of vitamin E on mouse models of allergic inflammation and adult-onset asthma in humans”. As such, according to Cosby A. Stone, MD, the study’s lead author, the team hypothesized that maternal levels of vitamin E could impact childhood respiratory outcomes.

To test this theory, the team conducted a study following 652 children and their mothers until the children turned 2. The median age of the infants was 50 days (53% of the babies were females).

The researchers highlighted that of the mothers included: 61% were white, 21% were black, 93% of the total had taken regular prenatal vitamins, and 22% had a history of asthma.

The team used post-pregnancy maternal samples to test mothers for two isoforms of vitamin E including alpha-tocopherol and gamma-tocopherol. Although there are 8 different isoforms, most research revolves around alpha- and gamma-tocopherols.

The mothers were also asked to complete annual questionnaires about their children’s recurrent wheezing, which was defined as:

· Wheezing in the past 12 months,

· Use of asthma medications in the past 12 months,

· Or physician diagnosis of asthma

According to Stone, “The major sources of vitamin E are oils. Sunflower and safflower oils are highest in the vitamin E isoform alpha-tocopherol, while corn, soy, and canola oil are higher in the vitamin E isoform gamma-tocopherol. Even though vitamin E is comprised of these individual isoforms, the isoforms have different effects on health in our human studies and animal experiments.”

These molecules can impact lung health in many ways by altering the tone of immune responses.

From past mouse models, Stone and team determined that alpha-tocopherol decreased allergic lung inflammation in offspring. Interestingly, in human studies, they found the molecule was associated with improved neonatal lung function and decreased risks of adult-onset asthma in women. Gamma-tocopherol had also been linked to decreased neutrophilic lung inflammation in rats and humans wit asthma.

According to the authors, the results showed that children who wheezed or required asthma medication were likely to have mothers who had lower levels of vitamin E — specifically alpha-tocopherol.

In the United States, diet often included high concentrations of corn and soy oil. Infant and prenatal vitamins are also made from these oils. However, the research outlined that the cooking oils are more beneficial than supplements to directly boost alpha-tocopherol levels — often times supplement labels aren’t 100% accurate.

Though there are many factors involved when choosing cooking oils and ingredients, physicians urge pregnant mothers to be mindful of the impact their vitamin deficiency could have on their future children.

The study, "Maternal Vitamin E Plasma Isoform Concentrations and Association with Child Wheezing and Asthma Outcomes," was published in The Journal of Allergy and Clinical Immunology.

This study was funded by a grant from the National Institutes of Health, National Institutes of Allergy and Infectious Diseases Asthma and Allergic Diseases Cooperative Research Center.