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Study under review: α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial.
Introduction
“Vitamin E” actually is not one single chemical, but instead refers to eight related fat-soluble compounds (shown in Figure 1). Although all eight vitamers are found naturally in foods and absorbed by the body, only α-tocopherol is believed to meet our body’s vitamin E requirements. For simplicity, vitamin E refers to α-tocopherol unless otherwise stated.

Vitamin E primarily functions as an antioxidant. Specifically, vitamin E maintains membrane integrity of all cells in the body by preventing the oxidation of the unsaturated fatty acids within their cell membranes. Tissues with cell membranes that are especially susceptible to oxidative damage include the lungs, brain, and retina. Red blood cells and LDL particles are also prone to oxidation.
The recommended daily allowance (RDA) for vitamin E is 15 milligrams per day. Yet, more than 90%[1] of adults consume less than 12 milligrams per day, with significantly lower intake among individuals who are obese compared to normal weight. Moreover, the RDAs are based on the requirements of healthy individuals, and more than one-third of the US adult population is obese and has metabolic syndrome. It is well established that both obesity[2] and metabolic syndrome[3] are linked to increased inflammation and oxidative stress that may increase vitamin E requirements.
The question remains, how does the chronic inflammation associated with metabolic syndrome influence vitamin E bioavailability? The current study evaluated whether co-ingestion of vitamin E with fat could increase its bioavailability for those who need it more, and also evaluated vitamin E pharmacokinetics in healthy participants and participants with metabolic syndrome.
Vitamin E is an essential antioxidant that functions primarily to protect cell membranes from oxidative damage. The study under review sought to evaluate how ingestion of fat could influence bioavailability for both healthy individuals and people with metabolic syndrome, a disease state associated with increased oxidative stress.
Who and what was studied?
What were the findings?
What does the study really tell us?
The big picture
Frequently Asked Questions
What should I know?
Other Articles in Issue #16 (February 2016)
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Dieting, with a side of extra protein
For many lifters, it’s been a mantra that you just can’t gain muscle while being in a heavy calorie deficit. That statement was put to the test in this trial of a high protein diet.
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Promoting ‘high quality’ weight loss: protein and weights
By Stuart Phillips, PhD
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Spice up your satiety?
The active ingredient in spicy food, capsaicin, seems to have some effect on satiety. But researchers weren’t quite sure what it was or how it happens, until this highly controlled experiment was done
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Little bugs for big depression
Your gut and your brain communicate much more often than you’d think. In fact, all the time. Hence the potential for consuming gut inhabitants (aka probiotics) and impacting brain-related maladies
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Fish oil incorporation: where do other fats fit in?
When you buy and take a fish oil supplement, the story doesn’t end there. It still needs to be incorporated into cell membranes. This study looked at how other fats may impact that process
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The Tyranny of the Outlier: Focusing on the best of the best sometimes diminishes the rest of us
By Lou Schuler
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Have a nice trip, see you next fall
Some preliminary evidence has pointed to a potentially greater risk of falls for elderly people taking vitamin D. That’s put to the test in this year-long randomized trial.
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A vitamin D-efense against multiple sclerosis
MS involves a complex interplay between the nervous and immune systems (and potentially others as well). This is the first trial looking at the safety and immune impact of vitamin D supplementation for MS patients.
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The newest index on the block… the hydration index!
Hydration has become more of a marketing term than a scientifically accurate one. These researchers created an index to specifically measure the hydration impact of different beverages, from milk to coffee to beer