Magnesium For Dehydration

Understanding magnesium for dehydration

When it comes to keeping well hydrated, it is common to only drink water to replenish the body’s requirements. While this is in fact the most important thing to do, it is also worth noting the composition of water and how the different minerals interact in our bodies. Water has a precise constitution of minerals, or electrolytes, which contribute to the natural balance of fluids required to perform the body’s vital functions. The body maintains the right amount of potassium, sodium, magnesium, calcium, phosphate and chloride through a process known as homeostasis. However, too little or too much water can negatively impact the body’s natural electrolyte balance.

In this article, we will focus on the importance of the magnesium electrolyte, its relationship with dehydration and the risk of magnesium deficiency resulting from dehydration. This will allow us to understand the role of magnesium in rehydration when the body becomes depleted of this vital mineral, and how one can safely restore it when dehydrated.

Importance and benefits

Magnesium is the most important mineral of the body but is often overlooked. It plays a crucial role in muscle contraction and nerve functions and has proven to be beneficial for fatigue, anxiety, depression, cramps and sleep troubles. It is also involved in bone formation with magnesium constituting 50% of the minerals found in the bone.

The magnesium ion Mg2+ is of paramount importance for 300 enzyme functions: it acts as a cofactor for all major cellular processes responsible for metabolism and protein synthesis. Research has found that magnesium deficiency can be linked to hypertension, osteoporosis and Type 2 Diabetes.1 

Thus this mineral which is the fourth most abundant in the body, not only keeps our metabolism working at its optimum but also prevents disease and self-regulates storage in kidneys and bones, thereby preventing extreme blood pressure fluctuations and muscle fatigue. While calcium and potassium are also electrolytes which are vital for muscle function, their bioavailability is significantly different when compared to magnesium in water.2

How does it affect dehydration?

Dehydration occurs when the body loses large amounts of water and subsequently a large amount of electrolytes such as calcium, potassium and sodium. This can happen after vomiting or diarrhoea. The first response is to retain as much fluid as possible, by excreting less urine and sweating less. Symptoms include dry mouth and increased feelings of thirst. The body can also go through severe dehydration, often in younger or older groups of people who have an altered thirst centre. Symptoms include dizziness and hypotension from a sudden drop in blood pressure. This can also occur during exercise without adequate hydration, causing severe muscle weakness and cramps. In these severe cases, the fluids must be rapidly restored with an oral electrolyte solution, such as sodium and chloride.

When compared to the other electrolytes given in suspension dissolved), Magnesium in its dissolved state has a tighter bond with water molecules than other minerals. In its dissolved state, magnesium bonds better with more water molecules, which means that when anhydrous magnesium chloride (magnesium chloride without any water) is dissolved in water alongside other minerals, it will hold more water molecules around it. Therefore its efficiency in holding and transporting water is also higher than calcium, potassium and sodium.4

In fact, magnesium salts dissolve a lot more than calcium salts, which is why they are prescribed as laxatives and antacids. They have an increased ability to deliver water to the body due to their higher bioavailability in a dissolved state.

Best sources of magnesium for dehydration

There are different types of magnesium compounds, as follows:

  • Magnesium L-threonate (MgT) is obtained when magnesium is paired with Threonic acid which comes from the breakdown of vitamin C.4 This means that vitamin C is an excellent pair for Magnesium to help in hydration. Pairing magnesium with vitamin C has also shown higher efficiency when treating conditions like osteoporosis 3 
  • Magnesium glycinate is a highly absorbable form of magnesium often used to address magnesium deficiency. It can indirectly support hydration by helping maintain adequate magnesium levels (magnesium deficiency)
  • Magnesium chloride is obtained when mixed with chlorine and is the best form of magnesium for water dissolution and absorption by the body, as comparison studies with magnesium sulphate have shown.5 It is readily available in anhydrous magnesium chloride form (salts) which can then be mixed with fluids. Magnesium chloride can also indirectly support hydration by helping maintain adequate magnesium levels (magnesium deficiency)

Vitamins such as vitamin C act as cofactors to magnesium and enhance its properties, as mentioned above. Furthermore, Vitamin D is an excellent pair to magnesium, as the two work together to influence the homeostasis of calcium, and correct function of the kidneys and liver.6

For optimal magnesium absorption and to avoid muscle weakness during exercise, it is common to find electrolyte drinks or sports drinks on the market which include this mineral in different compositions. Electrolyte powders are readily available and are added to liquids to increase the delivery of the mineral.

Other sources include foods and Mg supplements. Magnesium can be found in leafy veg, nuts and dark chocolate. The required daily intake is 330mg for individuals assigned male at birth and 310mg for individuals assigned female at birth.7

However as it is easily dissolved in water, fluid intake remains the safest and quickest way for efficient rehydration.

It is advisable to a medical practitioner before taking magnesium supplements.


The first step to treating dehydration starts with fluid intake. Fluid intake is usually sufficient to quench thirst but in case of severe dehydration, it is not sufficient. Severe dehydration can lead to magnesium deficiency and therefore an array of muscular/neurological complications. For optimum hydration, there are many sources of magnesium available on the market that can be taken along with water. It is best to consult your GP before taking any magnesium supplements. Magnesium has the ability to strongly bind with water molecules and retain water efficiently. The most effective way to increase the uptake of magnesium for hydration is when it is paired with cofactors that enhance the cellular processes of hydration. Magnesium along with vitamins C and D or in the form of Magnesium Chloride, Magnesium L-threonate, Magnesium glycinate etc. help increase the uptake of magnesium. Sports drinks often include these minerals for enhanced performance and quick recovery. Optimum magnesium levels in the body can also be achieved by maintaining a properly balanced diet.


  1. Office of dietary supplements - magnesium [Internet]. [cited 2023 Mar 30]. Available from:
  2. Jahnen-Dechent W, Ketteler M. Magnesium basics. Clin Kidney J [Internet]. 2012 Feb [cited 2023 Mar 30];5(Suppl 1):i3–14. Available from:
  3. Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition [Internet]. 1990 Feb 1 [cited 2023 Mar 30];9(1):48–55. Available from:
  4. Yao H, Xu J, Wang J, Zhang Y, Zheng N, Yue J, et al. Combination of magnesium ions and vitamin C alleviates synovitis and osteophyte formation in osteoarthritis of mice. Bioactive Materials [Internet]. 2021 May 1 [cited 2023 Mar 30];6(5):1341–52. Available from:
  5. PubChem. Threonic acid [Internet]. [cited 2023 Mar 30]. Available from:
  6. Uwitonze AM, Razzaque MS. Role of magnesium in vitamin d activation and function: Journal of Osteopathic Medicine [Internet]. 2018 Mar 1 [cited 2023 Mar 30];118(3):181–9. Available from:
  7. Read “dietary reference intakes for calcium, phosphorus, magnesium, vitamin d, and fluoride” at nap. Edu [Internet]. [cited 2023 Mar 30]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Amal Sefrioui

Master of Science (MSc), Bioengineering and Biomedical Engineering, Imperial College London

Amal, MSc, BEng: Amal graduated from Imperial College with a Master's in Biomedical Engineering, specializing in Biomaterials and Cancer Research. She has worked for 8 years in the field of medical engineering, in hospitals and laboratories, working with healthcare companies such as Siemens Healthineers and Roche Diagnostics. She has strong interpersonal skills and presentation skills, which helped her manage customer accounts and provide technical information to all relevant healthcare professionals. She is currently undertaking Medical Writing Experience with Klarity to further enhance her medical communication to the industry.

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