Do you also experience choice stress when looking for a vitamin E supplement for your horse? The advice and information platform for all horse and dog enthusiasts.

Prevent overdosing on vitamin E (and selenium)

It is possible to give your horse too much vitamin E, so be careful. Overdosing can lead to horses absorbing other nutrients and minerals less effectively. Negative effects have been shown at doses of five to ten times higher than the daily maintenance of 1000 IU for a horse weighing 550kg. Also, be cautious with vitamin E supplements containing selenium. Although many horses can benefit from a small amount of selenium, especially since Dutch hay often contains little selenium, this mineral can be toxic at concentrations eight times the daily dose. So, pay attention to how much selenium your horse's total diet contains (including hay, concentrate feed, and any vitamin pellets). The recommended daily dose of selenium is about 1 mg per day for an adult horse.

α-tocopherol is the most absorbable

When looking for a good vitamin E supplement for horses, it quickly becomes complicated. Vitamin E is the main fat-soluble antioxidant found in food. It consists of eight closely related vitamin E compounds. Together, these are called the vitamin E complex. There are four tocopherols and four tocotrienols:

α-, β-, γ-, and δ-tocopherol
α-, β-, γ-, and δ-tocotrienol

The most absorbable compound from the vitamin E complex is α-tocopherol. This substance is usually used in supplements. Most of the naturally occurring α-tocopherol can be found in wheat germ oil, but if you want to use that for your horse, you must give a liter or more per day. This is, of course, not feasible. An advantage of wheat germ oil is that it also contains Omega-6 fatty acids, which are important for the absorption and action of vitamin E. There are also a few other vitamin E compounds present that enhance each other's function. However, since giving a liter of wheat germ oil per day is not feasible, it is best to combine wheat germ oil with natural vitamin E.

Synthetic or natural vitamin E?

There are many supplements on the market that contain vitamin E. It is important to know that there is a significant difference in absorbability between various variants. The cheaper vitamin E, also known as synthetic vitamin E, is poorly absorbed by horses. It varies a bit per animal, but usually, it is a waste of money to feed this form of vitamin E to your horse. It is simply not absorbed into their blood but instead excreted back out with feces. An example of such a synthetic form of vitamin E is dl-α-tocopherol acetate, which is present in various supplements available in the Netherlands.

Natural or natural-like vitamin E is much better absorbed by horses and is, therefore, much more beneficial. Both d-α-tocopherol and RRR-α-tocopherol fall under natural vitamin E. However, it has been proven that the isomer RRR-α-tocopherol is the most absorbable; for example, this is present in wheat germ oil. But… these natural compounds can also be made in a lab. Therefore, the product is called ‘natural vitamin E’ because the molecular formula is exactly the same as that of vitamin E extracted from wheat germ oil, for example. However, it is artificially made. The absorbability, however, is the same, so it is a good product for your horse. It would be better to call this type of vitamin E natural-like rather than natural. Because many supplements market this artificial variant as natural vitamin E without specifying.

So, there are three types of vitamin E:

Synthetic (dl-α-tocopherol acetate): poorly absorbed
Natural-like (RRR-α-tocopherol): as absorbable as natural
Natural (d-α-tocopherol and RRR-α-tocopherol): highly absorbable

Grape extract is a powerful antioxidant

Grape seeds and skins are a byproduct of wine production, from which you can extract grape seed extract that is an excellent source of natural antioxidants. This extract protects against oxidative stress, the free radicals released during muscle damage caused by training and stress. Its effect is similar to that of vitamin E. Grape extract detoxifies and strengthens the immune system of animals.

Grape extract is rich in polyphenols and proanthocyanidin, also known as oligomeric proanthocyanidin (OPC). These are dark blue pigments found in plants, especially in the skin and seeds. They are also what make blueberries so healthy, for example. OPC is 20 times stronger as an antioxidant than vitamin C and 50 times stronger than vitamin E. It is a good way to protect animal cells from oxidative stress.

Conclusion: choose a natural and/or natural-like variant

When looking for a vitamin E supplement, choose at least a natural variant (wheat germ oil) supplemented with a natural-like vitamin E (RRR-a-tocopherol). A supplement based on wheat germ oil is preferred as it contains multiple forms of vitamin E and omega-6 for enhanced absorption. Additionally, adding grape extract is recommended to further increase the antioxidant action of the supplement.