Top 5 Vitamin & Mineral Supplements for Horses in Canada (2026) — Filling Forage Gaps Without Overdoing Selenium
Published on Friday, August 21, 2026
For most Canadian horses the gap a supplement actually needs to fill is trace minerals and vitamin E: hay covers energy and protein reasonably well, but vitamin E falls away as hay is stored, and copper, zinc and selenium levels track the soil the hay grew in. This category covers the products that close that gap — full vitamin-mineral premixes, mineral-led loose blends, and single-nutrient boosters. They matter most for horses on forage-only rations or fed below a commercial feed's label rate, and for broodmares, seniors and performance horses. Canadian buyers tend to weigh chelated (organic) trace mineral forms, a readable guaranteed analysis, CFIA registration, and dosing that won't collide with an already-fortified feed.
Top Picks Summary
What the Research Says About Vitamin and Mineral Supplementation for Horses
Scientific guidance and clinical studies support targeted vitamin and mineral supplementation when forage or feed does not meet a horse's life-stage or workload requirements. National recommendations (for example, NRC equine nutrient guidelines) are the baseline for amounts; peer-reviewed research highlights the roles of key nutrients — vitamin E and selenium as antioxidants, copper and zinc for connective tissue and immune function, and chelated forms of trace minerals for improved absorption. Evidence also stresses testing (hay, forage, blood) and dose control to avoid under- or over-supplementation.
NRC nutrient recommendations provide evidence-based targets for vitamins and minerals; supplements are intended to fill gaps between intake and these targets.
Vitamin E and selenium act as primary antioxidants for muscle and neurologic health; clinical studies link appropriate supplementation to reduced risk of deficiency-related conditions.
Chelated trace minerals (amino acid- or protein-complexed forms) frequently show better bioavailability in absorption studies compared with some inorganic salts, which can improve biological response at lower inclusion levels.
Premixes and balanced vitamin-mineral blends make consistent dosing simpler for herd management and reduce the risk of mineral interactions when formulated to established nutrient ratios (for example Ca:P balance).
Regional soil and forage variability in Canada can create predictable deficiencies (or surpluses) — testing forage and blood levels before long-term supplementation helps target interventions and avoid toxicity, particularly with selenium.
Frequently Asked Questions
Do I need a vitamin and mineral supplement if my horse already gets a commercial feed?
Only if you feed below the label rate. Fortified feeds such as Purina's Optimal line are balanced to deliver their full vitamin and mineral load at the recommended daily amount — feed half the scoop and the horse gets half the micronutrients. Horses on hay or pasture alone, or on a token handful of grain, are the ones a premix like Mad Barn Omneity or a loose mineral like Hoffman's Horse Mineral is designed for.
Is it safe to add a selenium supplement in Canada?
Only with numbers in front of you. NRC puts a 500 kg horse's selenium requirement at roughly 1 mg per day, and the upper safe level at about 2 mg per kg of dietary dry matter — close to 20 mg a day for that same horse. The margin between too little and too much is narrower than for most nutrients, and forage selenium varies widely between Canadian growing regions. Most accidental overdoses come from stacking a selenium product on top of an already-fortified premix or feed. Test your hay and talk to your veterinarian before adding one.
What is the difference between a premix and a loose mineral?
A premix such as Mad Barn Omneity or Masterfeeds Equine Mineral and Vitamin Premix is a concentrated, fully balanced package of vitamins, macro minerals and trace minerals, fed by the scoop in small daily amounts. A loose mineral like Hoffman's Horse Mineral is mineral-led with lighter vitamin fortification and is fed at a higher daily rate. On a hay-only diet the premix does more of the work — but follow the bag's feeding rate rather than matching scoop for scoop.
Which of these works best for a barn feeding several horses?
Masterfeeds Equine Mineral and Vitamin Premix is the herd-scale choice here: it is sold as a ration-balancing premix rather than a single-horse tub, which keeps the cost per head down when the same forage is fed across the barn. For one or two horses, the smaller 5 kg size of Mad Barn Omneity is easier to store and to finish while it is still fresh.
Conclusion
In Canada a vitamin and mineral supplement is a fix for a forage-driven gap, not a general tonic. The products profiled here — Mad Barn Omneity, Purina's Optimal vitamin and mineral supplement, Masterfeeds Equine Mineral and Vitamin Premix, Brooks Feed B-Complete Plus, and Hoffman's Horse Mineral — run from full premixes to mineral-led and B-vitamin-focused blends. For a hay-only diet, Mad Barn's Omneity premix is the most complete option on this list: it is CFIA-registered, made in Petersburg, Ontario, and built on organic (chelated) trace minerals. Masterfeeds is the one aimed at herd feeding, and Hoffman's suits mineral-specific corrections. Whichever you choose, add up the selenium already in the ration before you start, and have your hay tested if you plan to supplement long term.




