How to harvest magnesium for supplements

Magnesium is an essential mineral for health and well-being. It is highly underestimated and badly overlooked as a dietary necessity. As such, magnesium supplementation is highly recommended to improve your quality of life. This mineral has many physical and mental health benefits, from repairing DNA and stabilising hormonal systems to increasing energy and improving recovery after injury. 

Magnesium is the ninth-most abundant element in the universe and the eighth-most common in the Earth’s crust, accounting for around 13% of the planet’s total mass. However much of the magnesium we use for supplements and diet actually comes from seawater. Like salt, magnesium is dissolved in seawater and can be harvested through a process of evaporation and residue extraction.

Other ways to obtain magnesium include mining and laboratory production through advanced chemical processes. It is an essential mineral for all bodily processes and cell reproduction. Almost every transfer of energy between our cells involves magnesium, so having a deficiency can be debilitating and manifest severe symptoms.

The Dow process is used to harvest magnesium

The easiest way to obtain magnesium is through the Dow process – or extraction via the evaporation of seawater. This process requires no specialised tools or expensive machinery. It is very similar to the harvesting of sea salt. Large shallow pans are created along the coastline that fill up with seawater at high tide. As the tide recedes, the pans are exposed to sunlight and the seawater contained within starts to evaporate. Over the course of the day, the water disappears and a crystalline residue is left behind.

This residue is a combination of sodium chloride (salt) and magnesium chloride. It is swept up with brooms and removed from the dry pans with buckets. The residue is put through a chemical process to separate the magnesium from the sodium and other trace elements. This begins by using an electrolysis bath and clean water to create a saline solution from the residue.

This salty solution is then treated with lime (calcium oxide) to create a precipitated magnesium hydroxide. Next, laboratory workers will add a small amount of hydrochloric acid to the mixture to convert it into a partial hydrate of magnesium chloride – or, in simple terms, a purer form of magnesium salt. This salt is then heated until it becomes a molten, red-hot substance.

It then undergoes a process of electrolysis once again. Here, the magnesium ions in the salt gather at the negative terminal (cathode) and chlorine ions gather and are oxidised at the positive terminal (anode). Essentially, the chlorine is converted to a gas and escapes the solution, leaving behind pure magnesium which is scraped off the cathode. This is the magnesium that supplement manufacturers will purchase for their products.

Magnesium can be found naturally in certain foods

We do ingest small amounts of magnesium in our normal diet, however, this is sometimes not enough to prevent a magnesium deficiency. Our bodies get some of the necessary magnesium from foods such as nuts, spinach, avocado, cereals, whole grains, spices and several other leafy vegetables. Many people require additional magnesium, especially athletes and active individuals that burn a lot of energy and are susceptible to muscle damage.

Magnesium supplementation is the best way to increase your intake of this beneficial element. It can taste bitter, but many supplement companies will mix their magnesium with flavourings to give them a better taste. Be sure to only take supplements that have undergone laboratory tests and are approved by your local standards bureau or health department. Magnesium can help to minimise muscle cramps, depression, tiredness and lack of energy.


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Written by Joshua Oates

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