Higher levels of vitamin A in the diet linked with a lower risk of asthma

Eating more vitamin A during childhood has been linked to a lower risk of asthma and better lung function in the teenage years.

What is vitamin A?

Vitamin A is a nutrient that helps our organs to work properly. There are two types of vitamin A.

• The first type is found in meat (especially liver), fish and dairy products. This is called preformed vitamin A.
• The second type is called provitamin A and it is found in some fruits, vegetables and vitamin tablets. Provitamin A is a nutrient that your body can turn into vitamin A. The most common form of provitamin A is beta-carotene.

What did this study look at?

This study aimed to investigate whether higher levels of preformed vitamin A or provitamin beta-carotene were linked with better lung function and with the risk of asthma.

Researchers used information on diet, lung function and asthma from children in a research database in the UK. They looked at what a child’s diet was like at 7 years old and then how well their lungs were working at 15 years old. They also looked at any recorded cases of asthma at the ages of 7, 11 and 14 years.

What do the results show?

The results found that diets that included higher levels of preformed vitamin A (the type found naturally in meat and dairy) were linked with better lung function and a lower risk of asthma. In contrast, there was no evidence to suggest that higher levels of provitamin A, found in vitamin tablets, fruits and vegetables, had a positive impact on lung function or the risk of developing asthma.

Why is this important?

There is a lack of research into the effects of vitamin A on lung function and asthma in childhood. This study provides an interesting finding, suggesting that eating more vitamin A in childhood could be linked with better lung function and lower risk of asthma during the teenage years. This type of study shows a link between vitamin A levels and lung function, but does not show that one causes the other. More research is needed to establish exactly how the two are linked and whether any changes in the diet could have a positive effect.

Title: Dietary intake of vitamin A, lung function, and incident asthma in childhood

https://erj.ersjournals.com/content/early/2021/03/18/13993003.04407-2020