Alpha-Tocopherol Reduces Other Forms of Vitamin E

by | Jan 12, 2016 | 2003, Vitamin E, Vitamins

Written by Chrystal Moulton, Staff Writer. Study shows supplementation with 400IU of alpha-tocopherol can cause a 58% decrease in other active forms of vitamin E.

Research on the benefits of vitamin E has been growing in the last few decades. Some findings were able to demonstrate an inverse relationship between vitamin E and certain chronic diseases, particularly cancer and cardiovascular disease. However, despite the research, no consensus has been reached on the beneficial effects of vitamin E for cardiovascular disease or cancer.(1) This is because most trials testing vitamin E used only the alpha-tocopherol form. Later studies noted that in the presence of other forms such as gamma- or delta- tocopherol, positive results were most often observed. (2,3) In the current trial,(1) researchers wanted to test in humans the effect of alpha-tocopherol supplementation on serum levels of gamma- and delta-tocopherol.

One hundred eighty-four [184] nonsmoking adults were recruited to participate in a double-blind placebo controlled trial lasting two months. Participants had to be non-smokers who were not exposed in any way to tobacco smoke and did not consume more than 14 servings of alcohol per week. Persons who were taking vitamins had to abstain from their regular vitamin supplementation routine for 2 months before being eligible to participate in the trial. Twelve-hour Fasting blood samples were collected at baseline. Eligible participants were, then, randomly assigned to 1 of 4 groups:

  1. Placebo
  2. Vitamin C (500mg)
  3. Vitamin E (400IU or 296mg alpha-tocopherol)
  4. Vitamin C and vitamin E

Upon completion of the trial, another 12hr fasting blood sample was collected from each participant and serum levels of alpha-, gamma-, and delta-tocopherols were measured.

After two months of supplementation, researchers found that alpha-tocopherol significantly lowered serum gamma-tocopherol levels by 58% [baseline: 2.20μmol/L; follow-up: 1.00 μmol/L, p<0.0001]. alpha-Tocopherol supplementation also lowered the amount of individuals with detectable levels of serum delta-tocopherol. At baseline, 46% of participants who were assigned to the alpha-tocopherol protocol had detectable levels of delta-tocopherol. By the end, only 13% of them had detectable levels of serum delta-tocopherol (p<0.0001). Vitamin C supplementation did not affect body levels of alpha, beta, or delta tocopherols in Group 2. Also, vitamin C supplementation in Group 4 did not alter or stop the reduction of serum delta tocopherol levels. Results in Group 4 were similar to that of Group 3.

In the end, the authors concluded that 400IU supplementation with alpha-tocopherol (with or without vitamin C) significantly reduced serum concentrations of gamma- and delta-tocopherol in healthy individuals. As an interesting side note, the researchers found that participants who were regular consumers of vitamin E supplements prior to the study had a lower serum concentration of gamma-tocopherol at baseline—even after maintaining a regular diet during the required 2month withdrawal from all supplements. This is especially interesting since the typical American diet is much higher in gamma-tocopherol than the corresponding alpha form.(4) Researchers noted the finding was in agreement with a previous trial demonstrating a prolonged effect of alpha-tocopherol supplementation on serum gamma- and delta-tocopherol levels. (5,6) Additional research will need to be designed to assure that problems found from high levels of the d alpha form are not due to deficiencies created in other  tocopherols or related compounds”)

Source: Huang, Han-Yao, and Lawrence J. Appel. “Supplementation of diets with α-tocopherol reduces serum concentrations of γ-and δ-tocopherol in humans.” The Journal of nutrition 133.10 (2003): 3137-3140.

© 2003 American Society for Nutritional Sciences.

Posted April 25, 2014. 

Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.

References:

  1. Huang HY, Appel LJ. Supplementation of diets with alpha-tocopherol reduces serum concentrations of gamma- and delta-tocopherol in humans. J Nutr. 2003 Oct;133(10):3137-40.
  2. Helzlsouer, K. J., Huang, H. Y., Alberg, A. J., Hoffman, S., Burke, A, Norkus, E. P., Morris, J. S. & Comstock, G. W. (2000) Association between alpha-tocopherol, gamma-tocopherol, selenium, and subsequent prostate cancer. J. Natl. Cancer Inst. 92:2018-2023.
  3. Hartman, T. J., Albanes, D., Pietinen, P., Hartman, A. M., Rautalahti, M., Tangrea, J. A. & Taylor, P. R. (1998) The association between baseline vitamin E, selenium, and prostate cancer in the alpha-tocopherol, beta-carotene cancer prevention study. Cancer Epidemiol. Biomark. Prev. 7:335-340.
  4. Swanson JE, et al. Urinary excretion of 2,7, 8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman is a major route of elimination of gamma-tocopherol in humans. J Lipid Res. 1999 Apr;40(4):665-71.
  5. Handelman, G. J., Machlin, L. J., Fitch, K., Weiter, J. J. & Dratz, E. A. (1985) Oral α-tocopherol supplements decrease plasma gamma-tocopherol levels in humans. J. Nutr. 115:807-813.
  6. Handelman, G. J., Epstein, W. L., Peerson, J., Spiegelman, D., Machlin, L. J. & Dratz, E. A. (1994) Human adipose alpha-tocopherol and gamma-tocopherol kinetics during and after 1 y of alpha-tocopherol supplementation. Am. J. Clin. Nutr. 59:1025-1032.

“Research this old is normally superseded by more recent research, as larger and better studies may have been done. However we were unable to locate suitable ones.”