Hope the next info helps,

Sometimes too much of a good thing is bad -- and that seems to be the case when it comes to dietary supplements and the risk of lung cancer.

While higher blood levels of carotenoids such as beta-carotene, and retinol have been associated with a lower risk of developing lung cancer, getting these nutrients through dietary supplements may do the opposite.

A recent study found that individuals who took individual supplements of beta-carotene, retinol, and lutein, had a significantly elevated risk of developing lung cancer. This isn’t the first time that beta-carotene supplements were linked with more lung cancer, nor the only supplements that have been studied. Last year a study showed an increase in lung cancer with vitamin E supplements.

So why should getting these nutrients through diet help prevent lung cancer and consuming them through supplements increase the risk? The researchers in this study speculated that too much of a good thing may have an opposite effect -- perhaps a high dose of one nutrient interferes with the absorption of another -- but we don’t really know.

Wouldn’t it be easier if we could just take a pill? I guess my mom was right ages ago, when she interrupted our Saturday morning cartoons to make us eat a good breakfast. Our pleas for the magic food tablets equivalent to a meal (that one of our favorite characters was handed by his mom), didn’t cut it for her. Decades later, it seems she is still right. We simply don’t have a substitute for eating a healthy diet, and moderation still reigns. Too much of a good thing can be bad.

Oh – Since I prefer the glass-half-full approach, a few good dietary sources of these nutrients are:

* beta-carotene – carrots, sweet potatoes, spinach, and kale
* retinol – low-fat dairy products
* lutein – spinach, kale, and winter squash

source : about.com
What is abit scary to me is that Vitamin E In a dose of 400 mg used daily for 10 years,was found to raise the risk of lung cancer by 28% !!