Vitamin E and Horse Health: Myth or Miracle?

Vitamin E, widely referred to as the Wonder Supplement, might indeed live up to its reputation. According to a recent study, healthy adult horses fed vitamin E had higher concentrations of the vitamin in both blood and cerebrospinal fluid than control horses, indicating that vitamin E crosses the blood-brain-barrier and might be an important component of the treatment plan for horses with neurological diseases.

Vitamin E possesses potent antioxidant properties and has been widely touted as an important supplement for a variety of conditions including heart disease, cancer, and neurological diseases.

According to Nicola Pusterla, DVM, PhD, Dipl. ACVIM, associate professor in the department of Medicine and Epidemiology at the School of Veterinary Medicine at the University of California, Davis, "While it has been hypothesized that vitamin E may be beneficial in infectious neurological diseases and the vitamin is commonly administered to horses with neurologic and neuromuscular diseases, there is no evidence that vitamin E crosses the intact blood-brain barrier in horses."

The purpose of this study was to determine if blood and cerebrospinal fluid levels of a specific form of vitamin E, ¦Á-tocopherol, will increase following oral administration. Increased cerebrospinal fluid levels suggest that ¨¢-tocopherol does cross into the central nervous system where it could potentially be used to treat neurological diseases such as equine protozoal myeloencephalitis (EPM), equine herpesvirus (EHV)-1-induced neurological disease, and other encephalitides.

Ten healthy adult horses were included in this study and randomly divided into two groups. Horses in group A were supplemented with 1,000U of ¦Á-tocopherol per day (current National Research Council's recommended dose) while group B was supplemented with 10,000U per day (dose currently used to treat horses with neurological disease).

Both groups were supplemented for nine days and blood and cerebrospinal fluid samples were collected at baseline (prior to supplementation), intermittently throughout the nine days of treatment and following cessation of ¦Á-tocopherol administration.

"We found rapid and significant increases of ¦Á-tocopherol levels in both blood and cerebrospinal fluid in horses supplemented with 1,000U and 10,000U per day," reported Pusterla. "Also, the horses supplemented with 10,000U per day had higher levels compared to the horses receiving the lower dose."

These results suggest that high doses of vitamin E do reach the central nervous system and might exert beneficial antioxidant effects.

Research in this field is ongoing to assess vitamin E levels in horses with neurological disease.

The study, "Assessment of vitamin E concentrations in serum and cerebrospinal fluid of horses following oral administration of vitamin E," was published in the June 2008 edition of the American Journal of Veterinary Research.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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