Research has found people with a diet containing low levels of vitamins A and C increase their risk of developing asthma.
According to a report published in the journal Thorax, low levels of both vitamin A and C are linked to an increased risk of asthma.
Scientists completed a review of 40 studies and found people with the lowest levels of vitamin A had more severe asthma than other people with the condition.
The results differ to research published last year, which said there was no link between levels of antioxidants in the diet and asthma.
But this latest research has identified a connection between a vitamin A and C deficiency and asthma.
Experts at the Food Standards Agency (FSA) recommend the average man should consume 0.7mg of vitamin A a day and 0.6mg a day for a woman. Sources of vitamin A include cheese, eggs and oily fish such as mackerel.
Glenys Jones, a nutritionist with the Medical Research Council, said: “The data provided is interesting, but inconclusive.
‘It does however support the consistent advice of following a good, balanced diet, as poor quality diets of limited variability are associated with lower nutrient intakes.’