Multiple Vitamin Mineral Supplements for Horses

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Many people feed an equine ”multi” to their horse for nutritional insurance. However, there’s some debate among nutritionists and veterinarians as to whether the average horse truly needs it. In this two-part series, we’ll help you decide if your horse would benefit and, if he would, which product is your best choice.

This article is focusing on true ”insurance” products, those top-dressing equine multis that you put on top of the feed in relatively small amounts. Next month, we’ll look at multis that are also protein supplements and fed in larger amounts.

These are market-survey articles. We went window shopping on the Internet for multi supplements just like you would. We included only basic vitamin-and-mineral supplements, without extras like glucosamine, and only products for which full contact information, analysis and pricing was available on the company’s website.

Balance is as important to your horse’s feed as it is to your riding. Most feed grains are higher in phosphorus than calcium.

Balance is as important to your horse’s feed as it is to your riding. Most feed grains are higher in phosphorus than calcium.

Obviously dosage is important, although you wouldn’t know that by comparing the levels of nutrients that different supplements contain and deliver in their recommended doses. Using the NRC (National Research Council) basic recommendations as a guide, we’d like to see a top-dressed multi vitamin/mineral deliver about 50% of the requirements as a good ”insurance” level.

However, it’s not that simple. The horse’s basic diet often contains significant nutritional deficiencies, as well as excesses, that can further interfere with the availability of minerals that are in short supply. A horse eating only alfalfa hay has different needs than one eating only grass hay. And, there’s even tremendous nutrient variation among grass hays. With all the different types of hay in mind, it’s easy to understand why no single ideal vitamin/mineral formula is possible for all horses on all forages.

A comment that a product formulated for grass hays is ”light on calcium, phosphorus and magnesium,” but this isn’t necessarily a bad thing either. Remember that no fixed formula supplement can possibly actually balance all ”grass” hays. One product can’t be all things to all horses. It can’t fill the deficiencies one horse might have, while balancing excesses of another.

That said, we’ve set the targets in Table I to reflect the likely needs of a 500 kg (1100 pound) horse in light-to-moderate work on a diet based on grass hay. For more details on modifications that would be appropriate to your specific geographical area’s hays, you should contact an equine nutritionist, your local agricultural extension agent or your state’s veterinary/agricultural university.

Who Needs One'

If you’re already feeding the recommended amount of a highly fortified grain mix or complete feed, you likely don’t need to add any other vitamin or mineral supplementation. There may still be imbalances in your diet, but adding a balanced supplement on top probably won’t fix them. Horses maintained on pasture may have mineral deficiencies but do not need any vitamin supplementation, except perhaps vitamin E when being worked regularly.

Signs of dietary deficiencies or imbalances include problems with the horse’s:

• Coat, including sun fading

• Hooves and skin

• Bones and joints

• Muscles.

You may also see:

• Increased infections and allergies

• Anemia

• Poor healing.

We’re not saying diet is the only factor here, of course. It’s simply that sound nutrition can minimize many common health issues. If you’re seeing any of these problems in your horse, read on. Your horse may benefit.


Minerals are the most important ingredients in your supplement. You probably think of bones when you hear ”minerals,” but they do much more than form bone. Adequate mineral levels are required for virtually every body function. Your horse loses minerals every day in sweat, urine and manure. These basic losses need to be replaced.

The basic diet is your horse’s major source of minerals, and that’s where the problem lies. In nature, a horse would consume a wide variety of plants with different mineral profiles — just as we eat a variety of foods. The domestic horse has much less variety, usually eats the same hay all the time, and is at risk for deficiencies and imbalances.

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Vitamins also have essential roles to play in every body function. The horse can synthesize vitamin C to some extent but otherwise vitamins need to come from the diet. In Table II we list common nutrients in multis that aren’t really needed, because diet-related deficiencies don’t exist for them or aren’t suspected.

Note that most of the vitamins are there. Deficiencies of vitamin D, vitamin K and the B vitamins have never been documented in horses. However, B vitamins may not be present in predominantly hay diets in optimal nutritional amounts for exercised horses. Horses on pasture consume much more vitamin C than horses on hay, so moderate supplementation with vitamin C is reasonable.

Exercise also probably increases requirements. Vitamin A is one of the most well-researched vitamins, so you’ll find it in generous levels in all supplements. However, most horses don’t need any more than what is in their diet already. Horses in work should receive 1000 to 2000 IU/day of vitamin E (500 to 1000 when on pasture), but vitamin E has a short shelf life when mixed with minerals.

Bottom Line

Price is no guide to what you get in this category. Some of the pricier supplements provided the lowest levels of vitamins and minerals. The standout product, and the only one to provide 100% of the horse’s recommended daily vitamin and mineral intake, was Equivision’s Equine Nutrimix. When fed at our target of 50% of daily requirements, the cost per day is 42??.

Pennwoods’ Blue Label is also excellent for balance and nutrient potency. This supplement meets the 50% of requirements target when fed as directed, and at just 52?? per day.

If you’re OK on the calcium, phosphorus and magnesium levels, and simply need a good trace mineral supplement, Equerry’s Choice is a bargain at 28?? per day. It’s also a good choice for high-manganese hays.