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Mineral Types & A Bit About Magnesium


One of the first minerals I ever became aware of was magnesium, back in 2007 when I started researching going barefoot for my horses. Pretty much the only type of magnesium you could get back then was magnesium oxide, yet these days there are many different forms of magnesium we can feed our horses, i.e. magnesium carbonate, magnesium sulphate, magnesium-l-aspartate, to name a few.

There are also hundreds of papers published on it being vital for overall health, advising us that it's directly required daily for hundreds of chemical reactions in the body, and especially for nervous system and muscle function, energy metabolism and production, and with deficiencies manifesting in horses as nervous or wary, muscle tremors, poor work tolerance and the possibility of tying up.

Cut to today and the subject of mineral balancing has exploded onto the scene, considered an absolute essential part of the feedbowl. However, it's not just about the different minerals themselves, from your calciums to your zincs - for those of us non-chemists, the different mineral types, i.e organic, inorganic, chelated etc., can be utterly baffling, and let’s not forget absorption rates and percentages of mineral content. More mineral minefields, and real brain-ache for those of us in the non-chemist club, of which I’m a paid-up member. When I finally went the barefoot way, each week I would make up little pots of powders and potions to feed my horses, but when forage balancing became the rage, my kitchen became a regular dustbowl with clouds of the stuff everywhere and me getting an uninvited lungful way too often.

However, I soon had it pretty much licked, and a couple of years ago we produced our own mineral forage balancer, EquiVita, along with a decade's supply of super-strength rubber gloves and a crate-load of nifty face-masks.

But - I was still fairly clueless when it came to the chemical side of it all, and all those mineral-related organic/inorganic words were still a mystery to me (completely different to a plant grown with - or without - chemicals!), so off I went to research, and the following is pretty much what I came up with.

First off, I wanted to know a bit more about the differences between Inorganic & Organic minerals (mini Science Alert coming up).

  • Organic compounds are those that are bonded to carbon atoms (although just to confuse matters, carbon on its own is an inorganic mineral).
  • Inorganic compounds are not bonded to carbon atoms.

An example - two hydrogen atoms and one oxygen atom combine to form a water molecule H2O, which makes water an inorganic compound. Minerals dissolved in water are also inorganic ie. sodium and chloride in sea water.

Simples! Not . . .

Now here’s a thing - studies indicate that apparently it makes no difference to the body whether minerals are organic or inorganic when ingested - bear in mind I haven’t seen this research so can’t quote from it. But (apparently) the body knows instinctively what type of mineral is in the diet and what to do with it. There's no argument that when a mineral-deficient diet is supplemented with (balanced) inorganic minerals, there is a noticeable improvement in health. The body does not necessarily need its minerals bonded to carbon to be effective and utilisable.

So what do our horses get from their forage?

Organic sources of minerals typically come from plants. A plant takes up its minerals from the soil through its roots, they then combine with water and push through the plant, and the plant then uses them in its photosynthetic and metabolic processes. Inorganic sources of minerals come from soil attached to the plant material and also from natural drinking water with dissolved rock material, so minerals available from drinking water will vary depending upon the source of water. The horse has evolved to be able to absorb minerals from both plant and water sources.

Now to manufactured minerals, aka Chelated, aka Synthetic

Organic and inorganic minerals can also be manufactured, and this is known as chelated. Chelated minerals are those that have been man-made to attach a mineral to an organic ompound. Naturally, this process adds a cost to the product.

* Edited June'21 - several years on and there's new science that shows chelated minerals aren't the effective bioavailable solution they were once thought of. We're just putting together a report on this, and will post a separate Blog accordingly.

A bit about Magnesium, and those percentages

Magnesium is a naturally occurring mineral, and horses get around 60-100% of their daily magnesium needs from their forage, absorbed at a rate of between 40 - 60%. Magnesium deficiency occurs when there is strong grass growth – rapid growth grass is likely to be low in magnesium and sodium, and high in nitrogen and potassium. High potassium slows magnesium uptake while high sodium helps magnesium uptake (hence another reason why adding salt to the diet is beneficial), with calcium, phosphorus and the EFAs (essential fatty acids, aka the omegas) in the forage also influencing the ability to utilise and store magnesium. It's that 'balance' thing again.

  • Magnesium Oxide (MgO) – Magnesium oxide, or magnesia, is a solid white hygroscopic mineral that occurs naturally as 'periclase', which Wiki describes as 'a colourless mineral consisting of magnesium oxide, occurring chiefly in marble and limestone', apparently usually found in marble produced by metamorphism of dolomitic limestone - for the record, metamorphic rock makes up a large part of Planet Earth’s crust. MgO is one magnesium atom (Mg) bound to one oxygen atom (O). Studies show that magnesium oxide is absorbed at a rate of 70%, and by weight, MgO is 60.3% magnesium. This means that for a horse to absorb 15mg it would require 35mg of magnesium oxide. These levels are considered good concentration and absorption rates.
  • Magnesium-l-aspartate – Magnesium-l-aspartate is chelated magnesium. It's magnesium bound to an amino acid which makes it more easily absorbed - chelated magnesium achieves close to 100% absorption. But – before we get excited, the concentration of magnesium here is low at just 15.6%. This means 96mg of magnesium-l-aspartate would need to be supplemented for a horse to absorb just 15mg. Due to the expensive nature of chelated magnesium products, the inorganic form of MagOx provides much better value due to the higher levels of concentration and absorption rate. And comparing the absorption rates between naturally sourced organic magnesium from forage and the absorption of inorganic forms (magnesium oxide, carbonate, sulphate), both the inorganic and chelated forms of magnesium can achieve higher absorption to that of magnesium naturally found in our grazing.

To conclude

This is all well and good, but let’s also not forget the importance of a healthy gut to maximise the nutrient absorption. Digestion and absorption for all minerals is dependent upon a healthy functioning digestive system. Horses eating a high roughage diet and with constant gut motility will be far more efficient at absorbing valuable minerals than horses fed low roughage diets with limited gut motility.