The benefits of Vitamin E supplementation in horses

What is Vitamin E for horses?

Vitamin E is the name for a group of eight compounds that all have distinctive antioxidant activity. There are four tocopherols and four tocotrienols. Each is designated with an alpha-, beta-, gamma- or delta-.

Horses require Vitamin E in their diet to keep the muscles, nerve cells and all internal workings functioning smoothly. It is known primarily as a potent antioxidant, meaning it binds with and limits the damage caused by free radicals. This essential nutrient is naturally present in fresh grass so for those horses with limited turnout, whose main forage is hay, a Vitamin E deficiency is a possibility. This could mean more oxidative damage occurs in the cells, including those in muscles, nerves, and immune cells. Higher levels of Vitamin E may also be recommended for horses with certain health issues. Given that Vitamin E is a fat-soluble vitamin (stored in fat), it is not surprising that underweight horses may also have deficiencies. It has been recommended to supplement Vitamin E for these types of horses.

No matter what the horse’s workload Vitamin E plays a big role in both overall health and performance. When horses are exercising intensely, their requirement for antioxidants increases dramatically.

Would you know the difference between the ‘synthetic’ and ‘natural’ versions of Vitamin E used in horse supplements?

To understand the difference, it is necessary to know among the eight compounds, only two, Alpha-tocopherol and Gamma-tocopherol, possess the potent antioxidant properties that make the nutrient so important to the horse. Alpha-tocopherol is the most biologically active and is found most abundantly in the horse’s body.

There are numerous Vitamin E supplements available on the market, so we advise you to educate yourself in the differences in their bioavailability. The commonly referred to ‘natural’ and ‘synthetic’ forms of Vitamin E relates to the Alpha-tocopherol sub-group. natural Vitamin E (d-alpha-tocopherol), has been scientifically proven to be the most bioavailable form consisting of one isomer. In contrast synthetic Vitamin E (dl-alpha-tocopherol), contains a mixture of several isomers, not all of which are readily absorbed. However, synthetic Vitamin E is frequently used in supplements and feeds, even though it offers quite limited bioavailability to the horse. Horse owners should look for d-alpha-tocopherol (or d-alpha-tocopherol acetate) to indicate that the Vitamin E is derived from natural sources.

Your horse’s turnout and work routine can help you to determine whether he is taking in enough vitamin E, but a blood test from your Vet is the best way to determine with some certainty.