One-third of Americans said to have increased intake requirements for vitamin E.
Metabolic syndrome is the term for a condition in which a patient has at least three of the following factors: abdominal obesity, low HDL, high blood pressure, elevated blood glucose, or elevated triglycerides. It puts people at increased risk for developing heart disease and diabetes. Currently, about 1/3 of Americans can be classified as having metabolic syndrome.
New research from the Ohio State University suggests that patients with metabolic syndrome have impaired absorption of dietary vitamin E (α-tocopherol). Researchers from the university conducted a randomized, cross-over, double-blind trial to test absorption of vitamin E in healthy adults and adults with metabolic syndrome. The study included 10 patients in each group. Groups were given 15 mg of a form of vitamin E (hexadeuterium-labeled (d6)-RRR- α-tocopherol) along with 240 mL of nonfat, reduced-fat, or whole milk before blood collection at regular intervals for 72 hours. The study was designed to imitate a typical morning schedule for an average person who might wake up and take a vitamin with a glass of milk.
Baseline measurements revealed that metabolic syndrome patients had lower plasma α-tocopherol levels (P < 0.05) along with greater LDL and markers of inflammation, including IL-6, IL-10, and C-reactive protein. Absorption of vitamin E ranged between 26.1 percent for patients with metabolic syndrome and 29.5 percent for healthy patients. Metabolic syndrome patients had a lower AUC for vitamin E from 0 to 72 hours and lower maximal concentrations. The maximal concentrations ranged from 2.04 ± 0.14 micromol/L for metabolic syndrome patients and 2.73 ± 0.18 micromol/L for healthy patients. However, they had similar times to maximal concentration. Finally, the study found that the fat content of the milk the subjects drank did not affect vitamin E absorption.
There are several possible explanations for impaired absorption of vitamin E in metabolic syndrome patients. The study authors noted that metabolic syndrome patients had lower levels of two lipoproteins in the liver and small intestine. The intestinal lipoprotein helps absorption of vitamin E, while the hepatic lipoprotein helps the liver secrete fat and vitamin E into circulation. It is possible that the increased inflammation and oxidative stress associated with metabolic syndrome is responsible for the lower levels of these lipoproteins. However, the causal relationship between vitamin E levels and absorption and these lipoproteins has not been established.
This study implies that the one-third of Americans with metabolic syndrome have increased intake requirements for vitamin E, which is important to have in the body for its antioxidant properties in addition to its immune system and skin support.
There are limitations of the study, however. The sample size was very small, with only 10 patients in each of the group for a total of 20 subjects. In addition, the form of vitamin E used in the study is different from the form commonly found in supplements (which is α-tocopheryl acetate). It is unknown whether the two different forms will have different absorption profiles. Overall, clinicians may consider measuring the vitamin E levels of their patients with metabolic syndrome and suggesting supplementation with monitoring.
- A small randomized trial showed that patients with metabolic syndrome have lower baseline vitamin E levels and impaired vitamin E absorption.
- Vitamin E is important for its anti-oxidative properties as well as its immune system and skin support.
- The vitamin E form used in the study is different from the vitamin E used in most supplements, so the results may not be directly relatable.
Mah E, Sapper TN, Chitchumroonchokchai C, et al. “α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial.” Am J Clin Nutr. Epublished on October 7, 2015. doi: 10.3945/ajcn.115.118570