Which form of silicon is the best choice: hydrolyzed, orthosilicic acid, or diatomaceous earth? The advice and information platform for all horse and dog enthusiasts.

Almost all naturally occurring silicon in nature is 'locked' in very stable mineral compounds such as silicates and silicon oxide (sand). These minerals are so stable that they can hardly dissolve into a form that is absorbable in the digestive system of mammals. The silicon in these minerals is therefore not available as a supplement for humans and animals. Before it can be absorbed, the molecule must first be detached from these compounds.

Difficult to obtain

There are few minerals or metals that react as peculiarly as silicon when you want to do something with it. This is due to the electrons that surround the silicon molecule, which repel other particles. Silicon always wants to react back to silicon dioxide (SiO2), white sand. Anyone who wants to make a supplement containing silicon, therefore, faces a problem. The small-molecular forms of silicon (called monomers) are much better absorbed than the large molecules, the polymers. Silicon from food, such as plants, is in 'large' organic compounds. These are usually not 'chopped up' well enough by horses to pass through the intestinal wall. Since silicon is a very important mineral for tendons, muscles, ligaments, and bones, many horse owners want to give their horse a good dose of silicon daily. But this is only useful if the silicon in such a supplement is actually absorbed by the body. The only way to achieve this is to give the silicon as a liquid and then in a high concentration with very tiny silicon particles. The smaller, the easier they are absorbed in the intestines.

Orthosilicic acid: not in high concentrations

Through natural erosion, a monomeric form of silicon sometimes arises in low concentrations, known as orthosilicic acid (Si(OH)4). This substance is also called silicic acid, silicic acid, or ortho-silicic acid. This form can be absorbed by mammals, but only in low concentrations. Diatomaceous earth naturally contains this orthosilicic acid in low concentrations. The problem starts when you try to extract this form of silicon and put it in a more concentrated supplement. Then the orthosilicic acid starts to clump together, forming a gel-like material. The molecule size increases, making it more difficult for the silicon to pass through the intestinal wall. Concentrated orthosilicic acid is therefore no longer well absorbable. Pure silicic acid (100%) will always take on a solid form. Silicic acid can only be dissolved at a concentration of a maximum of 9 mmol per liter of water. That is very little, meaning you would have to give a lot of silicon-water to provide your horse with a useful dose of the mineral silicon. That is why a silicon supplement based on orthosilicic acid and diatomaceous earth is not preferred.

Types of silicon supplements

There are currently various supplements on the market that claim to contain absorbable silicon on the label. The oldest and perhaps most well-known of these supplements is diatomaceous earth. This product does indeed contain a small amount of absorbable silicon but in low concentrations. There are also liquid silicon supplements that claim to contain orthosilicic acid stabilized with the substance choline (CH-OSA). However, this stabilization only works at a very high pH. Afterward, water must be added to the solution to neutralize the pH, causing the silicic acid to revert to its preferred form, namely silicon dioxide. This lowers the concentration of absorbable silicon to about 2%. So even in this type of liquid supplement, the concentration of silicon particles is very low. Very few silicon particles reach your horse, so the supplement will hardly have any effect. Since the effective dosages in these products are so low, they are also very expensive in practice because you have to give more of them daily. Giving them in low doses is not useful.

Hydrolysis results in the smallest silicon particles

For now, hydrolysis is the only proven way to include many tiny silicon particles into a liquid supplement. Hydrolysis is the 'cutting' of particles/molecules (often nutrients) and is sometimes seen as predigestion. Hydrolyzed silicon contains 15% silicon dioxide, dissolved in minuscule particles, in water. When your horse receives a dose of these very small (nano) particles, the body will safely absorb the silicon. The horse's body regulates absorption using enzymes. The hydrolyzed silicon particles are so small (smaller than some viruses) that they pass through the blood vessel wall well. The horse decides how much to absorb, as needed. If you give a little too much, it's not a problem. Your horse will naturally excrete the excess silicon.

Conclusion: Only Hydrolyzed Silicon is Well Absorbable

The number of particles and whether they are small enough determine whether your horse can actually benefit from the silicon in a supplement. Because of the special properties of hydrolyzed silicon, the concentration of particles can be small enough to pass through the intestinal wall effectively. Therefore, it is always best to choose a supplement containing hydrolyzed silicon. The silicon molecules in orthosilicic acid, silicic acid, and diatomaceous earth are larger, making them less effective. If you want to give your horse the mineral silicon, choose hydrolyzed silicon.