Research has found that diets high in levels of vitamins A and C can stave off the condition.
A review of 40 studies has found that a diet low in the vital vitamins boosts the risk of developing the breathing disorder.
It discovered that people with low levels of the key vitamins were more likely to suffer from asthma than those without the condition.
Previous research has already shown that children who eat a Mediterranean-style diet packed with fruit, vegetables and nuts are less likely to develop asthma and allergies.
There is also evidence that vitamin E and antioxidants in the diet may prevent wheezing or asthma. Studies into increasing intake of vitamin C, magnesium and fish oils have all shown mixed benefits in trials.
But now experts have found that independently each vitamin was linked with an increase in the risk of asthma.
At least 5.4 million people in Britain are currently being treated for asthma – 1.1 million children and 4.3 million adults – and it costs the NHS over £996 million a year.
In the review, it was found that people with the lowest levels of vitamin A had more severe asthma than other sufferers.
This contradicts findings of a large-scale study published last year which found no link between levels of antioxidants in the diet and asthma.
But the latest researchers claim theirs is a more robust study.
Experts say people should be able to get their daily supply of vitamins A and C from a healthy diet. Sources of vitamin A include cheese, eggs, oily fish such as mackerel, milk, fortified margarine and yoghurt.
Recommended intakes are 0.7mg a day for an average man and 0.6mg a day for a woman.
The Government recommends children aged one to six have 400 micrograms a day of vitamin A, 500 micrograms aged seven to 10 and 600 micrograms aged 11 to 14.
Vitamin C is found in a wide variety of fruit and vegetables and good sources include peppers, broccoli, Brussels sprouts, sweet potatoes, oranges and kiwis. Adults are recommended in the review to have 40mg a day; children aged one to 10 30mg; and from 11 to 14, 35mg.
The research, published in the journal Thorax, found that, on average, men with asthma were lacking 26 per cent of their daily requirements of vitamin. Women with asthma were lacking 30 per cent.
Vitamin A intake was lower in people with severe asthma than in those with mild asthma by the equivalent of about half the recommended daily amount (50 per cent in men and 57 per cent in women). The authors, from the University of Nottingham, said: “For vitamin C, we found evidence of an increase of approximately 12 per cent in the odds of asthma associated with lower levels of intake of vitamin C.”
Leanne Male, assistant director of research at Asthma UK, said: “The jury is still out as to how exactly vitamin intake and asthma are related, and how vitamins might be able to help the 5.4 million people in the UK with asthma.
“Until further clinical trials have been carried out to establish the exact role of vitamins in both the development of asthma and treatment of asthma symptoms, we would advise everyone eats a healthy balanced diet, especially if they have a history of asthma and allergies in their family, or are pregnant.”