The 7 Best Vitamin and Mineral Supplements for Horses of 2026

Two ounces a day carries 1,000 IU of vitamin E, 3 mg of selenium, a full vitamin and mineral panel, and pre- and probiotics. That is the most concentrated daily dose in this group and the highest selenium figure of anything here. The last number is the one to notice: 3 mg is a serious dose, so this is not a product to stack with another selenium supplement or with a feed that is already fortified.

What makes the concentration worth paying for is everything riding along with it. The selenium is organic, the probiotics and prebiotics cover hindgut support you might otherwise buy as a second tub, and the bag comes with its own two-ounce scoop so the dose stays consistent. For a barn that would rather buy one product than three, that is the argument.

The risk is the horse, not the formula. Pellets get refused by some horses, and there is nothing more wasteful than a tub nobody eats, so introduce it at half a scoop mixed into a wet feed and hold off on the second bag until the first is going down. When a horse does eat it, this is the most complete single product on this list.

This is the formula for the horse in work. The guaranteed analysis per two-ounce serving runs longer than anything else here: 14.5% crude protein, lysine and methionine, calcium and phosphorus, magnesium, the full B-complex, 500 IU of vitamin E with selenium, plus zinc, copper and manganese.

The protein and amino acids are what separate it from a plain vitamin and mineral mix. On grass hay and a light workload that is nutrition the horse does not especially need; on a training ration built mostly on forage, the lysine and methionine are the part that helps him hold topline through a season. We read the label as a ration top-dress that happens to include vitamins, not a vitamin tub that happens to include protein.

Buy it when the workload is the reason the diet needs help. A retired horse in a paddock does not need the protein or the B-complex load, and a plain complete formula covers him for less. The value shows up in a horse being asked to hold condition through real work, and nowhere else.

The label is short: natural vitamin E, nothing else. That is the whole design, and it is the right answer when vitamin E is the thing your horse is short of. Hay gives it up in storage, and a dry-forage winter can leave a horse short even when everything else in the diet is right.

We have come to prefer the single nutrient for a horse with a real deficit. A combination product puts selenium into the horse before it delivers enough E, and a horse on a fortified feed is already getting selenium from somewhere. With one nutrient, raising the scoop does not unbalance anything else, which is exactly what the label promises and what makes this useful when a vet has called for a high dose.

What you give up is coverage. There is no selenium, no zinc and no B vitamins in the tub, so a horse short on more than E needs a second product, which is the case the E and selenium crumbles here are built for. What you get in exchange is precision: one number to raise or lower, and no risk of dragging another nutrient along with it.

Selenium is the mineral that depends on where your hay grew, and much of the country's forage is short of it. These crumbles pair 1 mg of selenium with 625 IU of vitamin E in a half-ounce serving — the dose we want for a horse on deficient ground — and a three-pound tub runs 96 days.

The crumble form is what makes it work in a real barn. It mixes through grain instead of sifting to the bottom, and the horses eat it, including the picky mare who normally sorts her feed. With a serving this small, the flavor is most of the battle, and this one wins it.

Check the selenium picture before you buy. If your hay runs high in it, or your feed is already fortified with it, this is the wrong product and a vitamin E only powder is the right one. Add the numbers from the whole ration rather than this tub alone, and remember the half-ounce serving is fixed, which is what you want for selenium.

A gallon jug, 64 days of feeding, and 300 mg of iron in every ounce. Red Cell is the least subtle product in this group, and that is the point. It is built around blood cell health, with iron and zinc for the immune side and B-complex vitamins for metabolism, and it goes onto the feed as a liquid rather than a powder to be measured and mixed.

We kept this one for the horse that is off his feed, out of condition or coming back from a hard season, the one where iron and B vitamins are the specific gap. A complete vitamin and mineral formula is a maintenance product; this reads more like a recovery one. It is also the only liquid here, which matters for a horse that will not take a powder no matter how it is disguised.

The catch is flavor. Yucca-sweetened liquid is a love-it-or-leave-it proposition, and a horse that refuses it will leave the whole meal, not just the supplement. If yours turns his nose up, the same formula comes as a pellet, which is the route we point people to for the horse that will not take it wet.

Magnesium gets sold as a calm-down product, and the label here leads with that. It is worth knowing what you are actually buying: a macromineral involved in muscle function, metabolism and nerve signaling, and one that forage can be short of. The calm reputation follows from correcting a gap that was making a horse tense in the first place.

MVP's version is unglamorous in the right way. Ten pounds of unflavored pellets, 80 servings to the tub, dosed by scoop into feed, with no herbs, no proprietary blend and no other minerals riding along. You can see exactly how much magnesium you are giving and adjust it, which matters when you are adding to a diet you cannot fully see.

Give it a month alongside whatever else you changed, because a calmer horse is as likely to come from more turnout and less grain as from a scoop. Changing the feed and the supplement in the same week tells you nothing about which one worked.

Where we reach for it is a horse on hay or pasture from ground known to run low, or one whose tension has been worked through against everything else first. A tub covers 80 servings, which is a long run for the money, and pellets are simpler to dose than a loose powder.