Mineral Chelate | BioStar US

Is Your Horse Really Getting His Minerals? Why Bioavailability Matters

Horse owners know how important macro- and microminerals are for their horses.  Hay and fresh forage used to provide the necessary minerals for horses; however, these days the mineral content of hay can be widely varied and in some cases deficient. Every commercial feed is fortified with minerals to ensure the horses are getting the range of minerals they need.  Multivitamin/mineral supplements have become even more popular to ensure horses get the macro- and microminerals critical to their health. The increased need high bioavailability macro- and micromineral supplements for horses has sent me down the rabbit hole in search of plant-sourced minerals, known as proteinates, but not from soy.  Presently in our Optimum line the minerals are plant-sourced from spirulina, an algae that provides its own amino acid chelation like grasses do. However BioStar needs greater customization for our clients — more than what spirulina can offer on its own. Follow me down the rabbit hole as I search for the answer!

Different forms of minerals:

There are two basic forms of minerals: inorganic and organic.  An inorganic mineral is essentially ground up rock; its chemical composition is without carbon. Ingredients listed as carbonates, oxides, dicalcium phosphate, monocalcium phosphate, and sulfates like zinc sulfate are common inorganic minerals.  Many commercial feeds and many supplement companies use inorganic minerals.

An organic mineral is bound or chelated to an organic material.  An organic mineral contains at least one carbon bond. Ingredients listed as amino acid chelates, proteinates, polysaccharide chelate complex, ascorbates, gluconates, citrates, and malic acid are examples of organic minerals.

In the equine feed and supplement industry the most common chelates are amino acid chelates, proteinates and gluconates.

Is Your Horse Really Getting His Minerals? Why Bioavailability Matters | BioStar USHow plants chelate minerals:

Plants rely on worms to create superhighways in the soil for the mycorrhizal fungi and beneficial bacteria.  The fungi can increase the surface area of the plant’s roots, as well as produce acids that are able to break up the inorganic minerals in the soil like phosphorus, calcium, zinc, copper, magnesium and iron. The fungi bring those minerals to the roots of the plant.

The plant in turn sends as much as 80% of the sugars it produces down to the roots, supporting the mycorrhizal fungi and the diverse soil organisms.

Once the minerals have been transported to the plant the process of chelation begins, binding free amino acids to the minerals. Plants need organic minerals to survive. When the horse eats the plant, the minerals in the plant are already chelated. Therefore when horses eat fresh forage and hay they are getting organic minerals.

Is Your Horse Really Getting His Minerals? Why Bioavailability Matters | BioStar US


Inorganic minerals such as oxides and carbonates have low bioavailability, ranging from 0-10%.  Sulfate minerals are moderately higher at 0-20%.

Gluconates range from 10-40% bioavailability, while amino acid chelates, proteinates, and polysaccharide chelate complex ranges from 50-75% bioavailability.

According to Kentucky Equine Research:

Most minerals occur in several forms that can be mixed into feed. For example, feed manufacturers can choose from at least six forms of manganese.  What makes one more desirable than the other? Two factors, digestibility and cost. As might be expected, the most easily digestible mineral forms (the chelates or proteinates) are also those with the highest cost.

Several feed companies use 25% chelated minerals with 75% inorganic minerals in their feeds.  This keeps the cost down, but sacrifices bioavailability.


Absorption of minerals occurs in the small intestine.  Unused and unabsorbed minerals are excreted. One of the important values of chelated minerals is that the organic structure around the mineral protects against antagonists in the feed and water the horse consumes.

Antagonists include sulfates, oxides, high sulfur content of dried distillers grains, iron, and minerals in hard water such as sulfur and calcium.  There can be reactions among inorganic trace minerals themselves. High levels of one inorganic trace mineral can decrease the availability of another.  Common mineral interactions include: copper and molybdenum, copper and zinc, sulfur and selenium, calcium and zinc, iron and manganese, and potassium and magnesium.

Inorganic forms of minerals break down before reaching the small intestine, and can form indigestible compounds with other feed components making the minerals unavailable for absorption that ends up being excreted.

Amino Acid chelates, proteinates, and polysaccharide chelates:

The USDA has a clear and concise description of these different organic complexes:

There are three types of chelates commonly used in the feed industry. Amino acid chelates typically use synthetic amino acids.  Proteinated chelates commonly are made using natural proteins to deliver dietary chelated trace elements. Polysaccharide chelates are natural carbohydrates bound to a trace element.

Since chelating improves the digestibility and absorption of immune supporting trace elements like zinc, copper, manganese, and cobalt, chelated proteinates or chelated polysaccharides are very useful to help in preventing illness, supporting good livestock health, and preventing the need for expensive treatments and reducing nutrient waste in manure.

Is Your Horse Really Getting His Minerals? Why Bioavailability Matters | BioStar US

Mineral chelates in equine feed:

Mineral chelates are predominantly used in feed and supplements for trace minerals such as copper, zinc, and selenium.  If you have seen selenium yeast on a label, that is a chelate of yeast to selenium.  What we do not see commonly in feeds or multi vitamin/mineral supplements are chelates used for macro minerals such as calcium, magnesium, and phosphorus.  Due to the costly nature of making plant sourced minerals, it is much more expensive for companies to use organic minerals over inorganic minerals.

The soy connection:

While amino acid chelates for animals are made using synthetic amino acids, proteinates are commonly made from amino acids from hydrolyzed soy proteins.  According to the Association of Feed Control Officials (AAFCO) the source of protein does not have to be declared on the label.

Polysaccharide chelates:

Polysaccharide chelates are predominantly made by extracting beta glucan from yeast and using that polysaccharide as the chelator to the mineral.  Polysaccharide trace mineral chelates were developed for ruminants (cattle, sheep, and goats) because polysaccharides are available to the microflora in the rumen.  Since horses are not ruminants, polysaccharide chelates provide no important benefit over amino acid chelates and proteinates in non-ruminants.

Plant sourced minerals:

When our horses eat hay and grass the minerals in the forage are already chelated with amino acids, making those minerals more bioavailable to both the plant and the horses.  Proteinates are essentially plant-sourced minerals, using soy for the proteins to chelate to the minerals.

For BioStar soy presents several issues. Soy is a common allergen for horses, it is genetically modified, and a recent FDA food report on their 2016 testing program showed that in 264 samples of soybeans, 66% were positive for glyphosate.  Research published in Food Chemistry showed that glyphosate tolerant genetically modified soybeans contained high residues of glyphosate (Bøhnab, Cuhraab, Traavikab, Sandenc, Fagand and Primiceriob. 2014).

Building a better multi vitamin/mineral:

The increased need of macro and micro minerals for horses that are bioavailable has sent me down the rabbit hole in search of plant sourced minerals to upgrade our Optimum EQ line.

I searched and searched.  I did not want to use amino acid chelates because they are from synthetic amino acids, and some companies only have one bond on the mineral.  I wanted an amino acid molecular “cage” surrounding the mineral for the highest bioavailability, to protect the minerals from antagonists and to prevent the formation of insoluble minerals precipitates in the stomach. I also did not want the proteinate to be made from soy.

Eureka! I was introduced to a small, family-run company who has been making proteinates for 40 years for the human supplement industry.  The plant they use is non-GMO rice and they use the full spectrum of amino acids including the essential amino acids. The proprietary process includes the minerals sequestered in the short chains because amino acids are not taken up as single molecules by the body.

We were able to create a customized plant-chelated, proteinate macro and micro mineral formula to provide more of the bioavailable minerals your horse needs.

A New Optimum:

We are reformulating our entire Optimum multi vitamin/mineral line of supplements to include our new minerals.  Look for new Optimum EQ formulas in September 2019.

Optimum EQ | BioStar US


Bøhnab, Cuhraab, Traavikab, Sandenc, Fagand and Primiceriob. (2014). Compositional differences in soybeans on the market: Glyphosate accumulates in Roundup Ready GM soybeans. Food Chemistry. 153, 207-215.



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