In the continuing debate over how much vitamin E is enough, a new study has found that high levels of blood lipids, such as cholesterol and triglycerides, can keep this essential micronutrient tied up in the blood stream and prevent vitamin E from reaching the tissues that need it.
[Photo: Dr. Maret Traber]
The research, just published in the American Journal of Clinical Nutrition, also suggested that measuring only blood levels may offer a distorted picture of whether or not a person has adequate amounts of this vitamin, and that past methods of estimating tissue levels are flawed.
The findings are significant, the scientists say, because more than 90 percent of the people in the United States who don’t take supplements lack the recommended amount of vitamin E in their diet.
Vitamin E is especially important in some places such as artery walls, the brain, liver, eyes and skin, but is essential in just about every tissue in the body. A powerful, fat-soluble antioxidant, it plays important roles in scavenging free radicals and neurologic function. In the diet, it’s most commonly obtained from cooking oils and some vegetables.
Some experts have suggested that recommended levels of vitamin E should be lowered. But because of these absorption issues, the recommended level of 15 milligrams per day is about right, said Dr. Maret Traber, the lead author of this study. Inadequate vitamin E intake remains a significant societal problem, she said.
“This research raises particular concern about people who are obese or have metabolic syndrome,” said Dr. Traber, who is the Helen P. Rumbel Professor for Micronutrient Research in the College of Public Health and Human Sciences at Oregon State University, and a principal investigator in OSU’s Linus Pauling Institute.
“People with elevated lipids in their blood plasma are facing increased inflammation as a result,” Dr. Traber said. “Almost every tissue in their body is under oxidative attack, and needs more vitamin E. But the vitamin E needed to protect these tissues is stuck on the freeway, in the circulatory system. It is going round and round instead of getting to the tissues where it is needed.”