Question
My gelding has been fed a natural-source, water-soluble vitamin E product since December. I just had his bloodwork checked again in March and there was no improvement. He is turned out 24/7 with pasture grass, when growing, and always has a round bale. Do all horses react similarly to vitamin E supplementation?
Answer
Blood vitamin E concentrations vary widely among healthy horses, and seasonal fluctuations have been observed, with levels lower in winter and higher in summer. Levels are also influenced by the amount of fat in the diet, age, and physiological state. As with individual differences in status, there can be large differences in the individual response to supplementation.
Blood levels may not be a reliable indicator of vitamin E stores in the body. Low blood levels may reflect deficiency, but once the body has reached adequate levels, it does not always show excessive levels because the body will try to homeostatically regulate the amount in the bloodstream.
There is little research-based evidence to support additional vitamin E supplementation above 500 IU per day in healthy horses receiving adequate dietary vitamin E intake. The recommended treatment dose for horses with neuromuscular conditions such as equine motor neuron disease (EMND) and vitamin E deficient myopathy (VEM) is between 5,000-10,000 IU per horse per day. A single 5,000 IU dose of natural-source, water-soluble vitamin E, like Nano•E, has been shown to double serum vitamin E levels within 12 hours of supplementation.
Have you evaluated your horse’s selenium status in addition to vitamin E, as these two important nutrients work in combination to provide total antioxidant support? Fresh, green grass is the best source of vitamin E, and when fed in combination with a well-fortified concentrate feed, either a ration balancer (<2 lb/day) or a traditional feed (5 lb or more), provides more than adequate vitamin E levels to meet requirements.
Nano•E is the best source of supplemental vitamin E; however, I would suggest having your horse’s vitamin E status rechecked during the spring and summer months to render a complete picture of your horse’s vitamin E status.
