Friday, March 27, 2015

Blood Fats Hold Vitamin E Captive, Study Shows

High levels of blood fats such as cholesterol and triglycerides can hold vitamin E in the blood and prevent it from reaching the tissues that require it, a small study says.

The findings suggest that checking only blood levels of vitamin E may not show whether a person has adequate levels of vitamin E, the researchers said. They also suggested that past methods used to measure vitamin E levels in tissues are flawed.

The study included 41 young and older adult women and men who ate collard greens treated with a chemical that enabled the researchers to track vitamin E as it moved through the participants’ bodies.

“In simple terms, we believe that less than one-third the amount of vitamin E is actually making it to the tissues where it’s most needed,” study author Maret Traber, a professor for micronutrient research at Oregon State University, said in a university news release.

“People with elevated [fats] in their blood plasma are facing increased inflammation as a result. Almost every tissue in their body is under oxidative attack, and needs more vitamin E,” Traber said. “But the vitamin E needed to protect these tissues is stuck on the freeway, in the circulatory system. It’s going round and round instead of getting to the tissues where it’s needed."

The study was published recently in the American Journal of Clinical Nutrition.

The research is important because more than 90% of Americans who don’t take vitamin E supplements lack the recommended amount of the vitamin in their diet, according to Traber and colleagues. Common dietary sources of vitamin E include cooking oils and some vegetables.

The researchers explained that vitamin E play an important role in artery walls, the brain, liver, eyes and skin, but it is essential in nearly every tissue in the body.

My Take:
Serum lipids (fats in the blood) are carriers for vitamin E and other fat soluble compounds. I am not convinced that elevated serum lipids results in a deficiency of vitamin E in the tissues. I think research into the active transport of vitamin E from serum lipids to the tissues will give more insight into this chemical pathway.

I do agree that measuring serum levels of vitamin E are flawed. This is also true for most vitamins. Laboratories are slowly adding tests that measure the vitamin content of red blood cells in lieu of serum tests. These new tests are much more accurate but currently are also much more expensive that serum testing.

In the tissues, vitamin E becomes oxidized in order to reduce vitamin C that was previously oxidized. This chemical process restores vitamin C so it can again serve as an antioxidant.

The Bottom Line:
Consider supplementing vitamin E. A daily supplement of 400 IU of mixed tocopherols is currently considered sufficient by the nutrition board.

Source: March 20, 2015 National Institutes of Health

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