A friend emailed me recently about my opinion whether minerals from plant sources are really superior to minerals that come from "rocks".
This was my very basic reply.
Gee - ALL minerals originally came from "rocks".
Inorganic minerals (sulfates, oxides, etc.) are basically the forms/compounds as they occur in nature (most elements combine in nature with other elements to form a "compound" such as copper plus iron plus sulfide equals chalcopyrite which we process to get the compound "copper sulfate"). They then pretty much hang around until nature or man works on them.
These compounds when mined and processed are graded according to purity - pharmaceutical grade being the purest, followed by food grade, feed grade, etc.
Minerals are natural compounds formed through geological processes. The term "mineral" encompasses not only the material's chemical composition but also the mineral's structure. Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms (organic compounds are usually excluded).
Chelation (from Greek χηλή, chelè, meaning claw) is the process of reversible binding (complexation) of a ligand - the chelant, chelator, chelating agent, sequestering agent, or complexing agent - to a metal ion, forming a metal complex, the chelate. The term is generally reserved for complexes in which the metal ion is bound to two or more atoms of the chelating agent, although the bonds may be any combination of coordination or ionic bonds.
Through the process of digestion, the body is capable of breaking the chemical bonds of ingested compounds and attaching them to protein molecules, making them available for absorption. Thus, the body is able to utilize the "inorganic" forms of minerals (the digestive system does a form of "chelation" here). Chelated minerals, often referred to as "organic" minerals, are simply mineral salts (dissolved metal ions) that have been attached, or bonded, to proteins, polysaccharides or amino acids. They are available as "proteinated" minerals which are attached to a basic protein molecule or as minerals that have been attached to specific or complex amino acids. The two main manufacturers of chelated minerals used in equine supplements are Truow Nutrition (Optimin) and ZinPro. Both make a variety of proteinated, poly and amino acid complexed minerals, available as single minerals or in combinations, which in turn, are used by the supplement manufacturers. No matter what brand of supplement you buy, the actual minerals used are most likely manufactured by Truow or ZinPro.
The concept is that chelated minerals are protected from competition for absorption and are delivered to the area where they will be best absorbed. A downside, if the bond is too strong, is that they might bypass the optimal absorption site in the digestive tract. Most studies on equine mineral requirements have been made with the inorganic forms of minerals. There are conflicting studies on whether or not chelation actually enhances absorption and utilization.
There's also the (remote) possibility that chelation could bypass the body's ability to NOT absorb excess minerals.
The concept that a supplement providing minerals from plant sources as superior is a bit questionable. True, eating plants will provide minerals in a more "natural" form - the plant has integrated the minerals dissolved from the soil into it's cells. This usually provides sufficient (often excess) calcium and some other major minerals but looking at the level of trace minerals such as copper, most available foodstuffs don't provide sufficient amounts of many micro minerals. The horse (or other animal) still has to process the minerals by attaching them to proteins to be absorbed.
In order to put these "plant minerals" into a supplement, they would have to process the plant material to extract the minerals from the plants to turn them into a usable form - which would put them right back into an inorganic form.
Also, while some plants have the ability to detoxify nonessential minerals, other plants can hyperaccumulate toxic levels of some potentially toxic metals. http://www.plantphys.net/article.php?ch=5&id=84