Deficiency in Vitamins A, C, E Tied to Asthma Risk

A deficiency in vitamins A, C and E may cause an increased risk of asthma, according to a British review. Researchers reviewed 40 studies conducted between 1980 and 2007 and found people with asthma had a significantly lower dietary intake of vitamin A than those without the disease. The average intake among those with asthma was 182 mg day, which is between a quarter and a third of recommended daily intake. The review authors also found that people with severe asthma had a significantly lower intake of vitamin C (about half the recommended daily intake) than those with mild asthma. In addition, low circulating levels of vitamin C in the blood and lower dietary intake of foods containing vitamin C were associated with a 12 percent increased risk of asthma.

No association between vitamin E intake and asthma risk was found, but blood levels of vitamin E were much lower among people with severe asthma than in those with mild asthma. Those with severe asthma had an average vitamin E intake of 2 mgd, which is 20 percent lower than the daily recommended amount, the review authors said.

The report was published in the current issue of Thorax.