Low vitamin intake may increase the risk and severity of asthma, according to a study
conducted by researchers from Nottingham University and published in the journal Thorax.
"Our findings indicate that low levels of vitamin C intake and to a lesser extent vitamin A are consistently associated with asthma risk to a degree that, if causal, would be sufficient to be clinically relevant," said lead researcher Jo Leonardi-Bee.
Bee said that further research was needed to determine whether insufficient vitamin levels might actually be a cause of asthma.
The researchers combined the results of 40 different studies into the relationship between vitamin levels and asthma risk carried out between 1980 and 2007. They found that people with asthma had a significantly lower daily intake of vitamin A than those without the disease. They also found that those with more severe asthma had a significantly lower vitamin A intake than those with a milder form.
People with severe asthma had a vitamin A intake that was 50 percent too low.
Analysis of vitamin C data revealed that people with insufficient vitamin C intake had a statistically significant 12 percent higher risk of developing asthma than those with a higher intake of the vitamin.
Vitamin C is common in fresh fruit and vegetables. Vitamin A is found in yellow or orange vegetables, such as carrots and sweet potatoes, as well as in certain animal foods.
The researchers found no relationship between vitamin E intake and asthma risk. They did find, however, that people with severe asthma had significantly lower levels of the vitamin in their blood than people with mild asthma.
People with severe asthma had vitamin E levels suggesting a daily intake that was 20 percent too low.
In another recent study, published in the American Journal of Respiratory and Critical Care Medicine, researchers found that children with severe asthma had lower blood levels of vitamin D than children with milder asthma. (Natural News, 10.10.2009)
Sources for this story include: news.bbc.co.uk. http://www.naturalnews.com/027210_asthma_vitamin_A_vitamin_C.html