Vitamin E
Vitamin E discussions come up all the time! There’s a lot of information out there, here’s a breakdown:
All horses (and mules and donkeys) require Vitamin E. It’s an important fat soluble vitamin that’s involved in nerve and muscle function, and works as part of the defense system of the body. It is an antioxidant; oxidation is a normal metabolic process but the free radicals it produces are can be damaging to cells. Antioxidants like Vitamin E help reduce their negative effects.
Equines need 1-2 IU per kgof bodyweight daily. So for the average horse, they need to take in 500-1000 IU daily as a minimum. Some equines benefit from additional Vitamin E in the diet. Different animals seem to have different requirements for their baseline, and then animals with disorders such as muscle myopathies or neurologic disorders may need more. A horse on good pasture 24/7 is likely going to meet its requirements and have a little extra to store as well - Vit E can be stored in fat as a clever way of ensuring the horse can access Vit E during the winter months when green growing grass is rare. But not all horses are on good green pasture 24/7 and may need some supplementation.
Most feeds are going to provide 1000-2000 IU of synthetic Vitamin E when fed at the recommended feeding rate. Why is this? Quality feeds are formulated to provide what is lacking in the forage portion of an equine diet. The NRC requirement for horses is listed at 1-2 IU per day per kg of body weight. Feed companies typically use a synthetic Vitamin E in feeds (listed as dl-alpha-tocopherol) because natural vitamin E (d-alpha-tocopherol) is not very stable and will break down in the presence of other feed ingredients as well as in high temperatures or when exposed to light. Contrary to a lot of Facebook claims, horses CAN utilize synthetic vitamin E; they just require more of it because it isn’t absorbed as well as natural vitamin E. So you may need to feed extra of the synthetic form, which is why there’s usually more than the base 500-1000 IU provided.
Supplementation is sometimes needed when a horse needs more than minimum required amounts. A blood serum test is available to see if your horse is within the ideal window (side note- the ONLY two blood tests that are valid for nutritional needs in horses are Vitamin E and Selenium). Most nutritionists will tell you running a yearly or twice yearly serum Vitamin E test is a good plan for breeding stock, performance animals and those with advanced needs. It’s nice to test periodically to ensure the amount and type of vitmain E supplement you’re feeding is actually effective
The type of Vitamin E supplement matters- when choosing a supplement, I recommend people purchase a natural, water soluble micellized form of the vitamin. These are the types that are shown through research to impact blood serum values the quickest and also the most. These kinds do of course cost more- you get what you pay for in this example, but they are also going to be the most effective. In the long run, they cost you less. My go-to recommendations in order of cost effectiveness are Stuart’s Emcelle, SmartEquine (SmartPak) Smart and Simple liquid Vitamin E, and KER’s Nano E.
The amount of extra Vitamin E is going to be dictated by the individual horse’s needs and/or bloodwork. Some benefit from just 1-2000 IU more per day where the advanced neuro cases may need 6000 IU per day. This is a good place to consult a professional- Vitamin E can technically be toxic when feed too much, but it’s also an expensive addtion so it makes sense to use just the right amount.
More questions about Vitamin E? Call me!