Vitamins for Horses

The essential vitamins for horses include the fat-soluble vitamins A, D, E, and K, as well as the water-soluble B-vitamins and vitamin C. Horses do not always need all of these vitamins supplemented at the same level, because some are supplied by fresh forage and some B-vitamins and vitamin C can be synthesized in the body or hindgut. However, in many cases, horses benefit from supplemental B-vitamins to support hoof health, energy metabolism, appetite, nerve function, and overall health, even when overt deficiency is not obvious. Biotin is a good example, because it is a B-vitamin and supplementation at 20 mg per day has been shown to improve hoof growth and hoof quality. The vitamins most likely to require closer attention depend on the horse’s diet and management, but vitamin E and vitamin A activity are common concerns because both are lacking in grass hay.

B-vitamins support energy metabolism, red blood cell production, nerve function, appetite, and normal tissue maintenance in horses. They also help the horse convert carbohydrates, fat, and protein into usable energy and are involved in many enzymatic reactions throughout the body. Some B-vitamins are produced in the hindgut, but supplemental intake may still be beneficial in horses under stress, in hard work, or with impaired digestive function. Biotin is a B-vitamin for which there is no established dietary requirement in horses, but supplementation at 20 mg per day has been shown to improve hoof growth and hoof quality when fed consistently over time. Mad Barn’s Omneity^® provides full B-vitamin fortification along with 1,000 IU of vitamin E and 20 mg of biotin per serving.

The best vitamin supplement for horses on a forage-based diet is one that helps replace the nutrients commonly low in hay and pasture. In most cases, that includes vitamin E, full B-vitamin fortification, biotin, and balanced trace minerals provided in a concentrated serving. This is important because forage supplies energy and fibre, but it does not always provide enough vitamins and minerals to fully balance the diet. Mad Barn’s Omneity^® is formulated for this purpose, providing full B-vitamin fortification, 1,000 IU of vitamin E, 20 mg of biotin, organic trace minerals, amino acids, a low-NSC formula, and no added iron in one daily serving. For horses with higher nutritional demands, including metabolic horses or those consuming high-iron forage, AminoTrace+ may be a better fit.

Yes, horses on hay need a vitamin and mineral supplement to help balance the diet. Hay does not reliably supply all of the vitamins and minerals horses need in the right amounts. Fresh grass is a rich source of vitamin E and beta-carotene, which the horse converts to vitamin A. Once forage is cut and stored as hay, the amounts of vitamin E and beta-carotene begin to decline, so hay-fed horses usually get less of these nutrients than horses eating fresh pasture. Hay is also commonly low in important trace minerals such as copper and zinc, which are needed to support hoof quality, immune function, skin and coat health, and many normal metabolic processes. Mad Barn’s Omneity^® is designed to provide those missing nutrients in horses fed mostly stored forage. It was formulated based on thousands of forage and grain diet analyses to help bring the majority of feeding programs into balance.

A good horse vitamin supplement should provide enough of the right nutrients to meaningfully improve the balance of the diet at the recommended serving size. For many horses, that means providing a full serving of vitamin E, complete B-vitamin fortification, 20 mg of biotin for hoof support, and trace minerals in bioavailable forms. It should also be concentrated enough to work in horses eating mostly forage or less than the recommended amount of fortified feed. Omneity^® is designed for this purpose, providing 1,000 IU of vitamin E, full B-vitamin fortification, 20 mg of biotin, and organic trace minerals in one daily serving.

Horses on complete feeds or senior feeds may still need a vitamin supplement if those feeds are not fed at the manufacturer’s recommended rate. Many horses, especially easy keepers or horses on calorie-controlled diets, are fed less than the amount needed to supply the intended vitamin and mineral fortification. This can leave gaps in micronutrient intake even when the feed itself is fortified. In these situations, a concentrated supplement such as Mad Barn’s Omneity^® can help fill those gaps without adding extra sugar, starch, or calories.

The best vitamin supplement for horses who need a low-NSC diet is one that provides concentrated vitamins and minerals without adding significant energy or non-structural carbohydrates (sugar and starch). This is important for horses with insulin dysregulation, laminitis risk, or other metabolic concerns, because the total diet often needs to stay below 10% NSC while still meeting micronutrient needs. AminoTrace+ is formulated for this purpose, using low-NSC ingredients, no added iron, organic trace minerals, and key amino acids in a concentrated pellet. AminoTrace+ also has a very low NSC, and because it is fed in a small daily serving, it contributes only minimal sugar and starch to the overall diet.

Horses with PPID, commonly called Cushing’s disease, need the same essential vitamins as other horses, but they often need those nutrients supplied within a low-NSC feeding program. Vitamin E is especially important because these horses are frequently managed on restricted pasture or stored forage, which lowers natural vitamin E intake. They also need balanced trace minerals, amino acids, and antioxidant support without extra sugar or starch. AminoTrace+ is often used in these horses because it provides concentrated vitamin and mineral support in a low-calorie, low-NSC pellet with no added iron.

Growing horses have higher vitamin and mineral requirements than mature horses at maintenance because they are building bone, muscle, connective tissue, and new body mass. Vitamin E is one of the vitamins that deserves close attention during growth, and balanced intake of all essential vitamins becomes more important because deficiencies or imbalances can affect normal development. Growing horses also need adequate protein and the right amino acid profile, so vitamins should be considered as part of the overall diet rather than in isolation. Omneity^® can help balance the vitamin and mineral side of the diet, but some growing horses may also need more calories or additional protein depending on forage quality and growth rate.

Pregnant and especially lactating broodmares have higher vitamin requirements than horses at maintenance, so the diet needs to provide a well-balanced supply of essential vitamins rather than focusing on just one nutrient. Vitamin E deserves particular attention because requirements increase during late gestation and lactation, and intake may be limited when mares are eating stored forage instead of fresh pasture. Vitamin A activity can also decline in hay-based diets because beta-carotene breaks down during storage. Omneity^® can help supply vitamins and trace minerals in broodmare diets, although many mares will also need additional feed or protein sources to meet their energy and amino acid requirements.