Transcript:

[0:00]

Hi everyone, welcome back to Mad Barn Academy, and if you’re new here, welcome. We hope to earn your subscription today, and a big thank you to everyone who’s liked and subscribed to our channel thus far — we greatly appreciate the continued support. I’m Dr. Fran Row, one of the veterinary nutritionists here at Mad Barn. Today I wanted to talk about vitamin E. Our team certainly gets a lot of questions about vitamin E supplementation, but we also find that many horse owners don’t realize their horses might be deficient in vitamin E intake. So today we’ll do a quick deep dive into vitamin E and why it’s so important.

[0:40]

Vitamin E is a general term that encompasses a group of eight very similar molecules: four tocopherols and four tocotrienols. Alpha-tocopherol is considered “true” vitamin E because it’s the form most abundant in the body and most bioactive. From here on out, when I say vitamin E, I’m really talking specifically about alpha-tocopherol. Alpha-tocopherol can be further classified as either natural or synthetic, which just refers to the chemical structure. Natural is the most bioavailable form and is denoted by the “d-” prefix.

[1:32]

Vitamin E plays the extremely important role of antioxidant in the body. Antioxidants neutralize free radicals and protect the body against oxidative stress. Free radicals are unstable molecules that form naturally from various metabolic processes. In an effort to stabilize, they steal electrons from other molecules — especially concerning when they steal from DNA or cell membranes. Overproduction of free radicals occurs during high metabolic demand (like exercise) or during immune challenges (like illness or inflammation). Too much free radical damage can result in cell death. Vitamin E fights free radical damage by neutralizing them before they can damage cell membranes. It’s incorporated into all cell membranes, but found in higher amounts in neurons and immune cells.

[2:50]

We can’t talk about vitamin E without mentioning its partner in crime: selenium. Vitamin E and selenium are the “dream team” of antioxidants. Selenium-containing enzymes have their own antioxidant function by reducing harmful peroxides — sometimes produced during vitamin E’s free radical neutralization process. These enzymes also reactivate vitamin E so it can keep working after each free radical interaction. I’ll be doing a video on selenium next since it pairs so well with this topic.

[4:06]

Vitamin E requirements have been established by the NRC: 1–2 IU/kg body weight/day, depending on physiological status. These are baseline numbers to prevent deficiency, not necessarily optimal intakes. Many situations — anything increasing metabolic demand or oxidative stress — may benefit from higher intake. The upper tolerable limit is >20 IU/kg/day, so toxicity risk is very low. Exceptionally high intake can impair blood clotting, bone mineralization, and vitamin A absorption, but this is extremely uncommon.

[5:37]

In theory, horses meet vitamin E needs by grazing fresh green pasture. Vitamin E is concentrated in leaves of grasses and legumes; immature plants contain more than mature plants. Vitamin E degrades rapidly once pasture is cut and dried for hay — hay may contain up to 85% less vitamin E than fresh forage. Horses store vitamin E in cell membranes and fatty tissues, using these stores in winter when pasture is unavailable, but these stores may not sustain optimal health, especially in exercising horses, pregnant/lactating mares, and other high-demand stages.

[6:58]

Vitamin E deficiency is most common in horses without access to green grass. Many North American regions lack quality pasture, and some horses have restricted pasture access (for example, due to metabolic disease risk). Deficiency results in neuromuscular disease, often with an insidious onset; sometimes acute signs develop after stressors like illness or travel. Common signs include progressive weakness, ataxia (poor coordination), muscle atrophy, tremors, and possibly increased episodes of tying-up. Severe cases may show a distinctive stance: low head/neck carriage with feet close together as if standing on a ball.

[8:38]

Diseases linked to vitamin E deficiency include several neuromuscular conditions. Some respond to supplementation; others do not, depending on the disease process. For non-responsive cases, prognosis is poor — both for athletic potential and survival — which is why prevention is key.

[9:39]

To determine vitamin E status, your vet can submit bloodwork. If results are marginal or deficient, high-dose vitamin E supplementation for several months is often recommended, with periodic rechecks. Prognosis is best if deficiency is caught early, before neurological signs develop.

[10:20]

When supplementing vitamin E, look for natural vitamin E (listed as “d-alpha-tocopherol”) — it’s the most bioavailable form. Synthetic vitamin E (“dl-alpha-tocopherol”) is less bioavailable. Both liquid and non-liquid forms can be bioavailable if natural; liquid water-soluble forms are most effective for rapidly restoring tissue levels, so they’re often used in deficiency treatment. Powders or pellets restore levels more slowly and are best for non-deficient horses who could still benefit from extra supplementation, such as those in work or lactating.

[11:56]

Here are today’s references. Thanks for taking the time to listen — I hope you found this helpful. Don’t forget to like and subscribe, and check out the other videos on our channel. Selenium will be the next topic since it pairs well with today’s discussion, so check back soon. Additional links are in the description below. Bye — until next time.