A new study published in the journal BMJ Diet Prevention & Health reported that high vitamin A, E, and D intake could be associated with decreased respiratory problems in adults.

Researchers propose that the results require further analysis between various ethnic groups and geographies in light of the ongoing coronavirus pandemic.

How are vitamins tied to respiratory health?

Health plays a crucial role in decreasing the likelihood of many illnesses, and vitamins A, E, C, and D have also been thought to improve the immune system. However, the European Union and the American Nutrition Association now say that these vitamins can also help reduce respiratory infections.

The researchers studied whether the consumption of these vitamins from both diet and supplements could be related to the prevalence of respiratory complaints.

Information was obtained from 6115 adult participants in the 2008-2016 National Diet and Nutrition Survey Rolling Program (NDNS RP) who completed three or more days of dietary diaries. NDNS RP is a rolling survey that gathers information annually about all foods and beverages eaten by approximately 1,000 randomly chosen persons residing in private households throughout the United Kingdom.

Researchers looked at food consumption and possibly influential variables such as age, sex, weight (BMI), smoking, household income, and overall energy consumption. There were 33 cases of respiratory problems in total. These respondents were usually older and less likely to state that they routinely take vitamins A, E, C, or D supplements.

There was no apparent correlation between BMI and vitamin consumption or between BMI and respiratory symptoms. However, the consumption of vitamins A and E from both diet and supplements was associated with a lower prevalence of respiratory problems among participants.

Significant dietary sources of vitamin A include liver, whole milk, and cheese, as well as carrots, dark green leafy vegetables, and orange-colored fruits. Significant dietary sources of vitamin E include vegetable oils, nuts, and seeds.

And vitamin D consumption from supplements, but not food, has been linked with fewer respiratory problems, leading researchers to say that the results contribute to the ongoing scientific discussion on the importance of vitamin D supplementation.

Further analysis is required to determine the consequences of the present study in the context of the current pandemic coronavirus disease using evidence from longitudinal cohorts, according to the research team.

Shane McAuliffe, Science Communications Chief for the NNEdPro Nutrition & COVID-19 Task Force, recognized the limitations of the study, adding, however, that it contributes more to the growing body of interest and evidence of the importance of vitamin D in respiratory health.