October 1, 2025 Merike Pulk

Magnesium - an indispensable helper for the body

Magnesium is a hard-working mineral that has many functions in the body. It plays an important role in both bone formation and bone density maintenance. In addition, magnesium is involved in the activity of more than 300 different enzymes, helping to regulate biochemical reactions (such as protein synthesis) in our body.

What is magnesium and why your body needs it?

Magnesium is a water-soluble mineral that has numerous important roles in the body, as we have discussed earlier. The most important of these are:

Participation in bone formation and maintenance of bone density as we age.
Regulation of blood pressure and cholesterol production.
Regulation of nerve and muscle function throughout the body, including the heart muscle.
Facilitating the digestion of fatty acids and proteins and regulating blood sugar levels.
Supporting deep and restorative sleep.
Reducing the level of the stress hormone cortisol in the body.
Participation in energy production and protein synthesis.

Long-term magnesium deficiency potential health problems:

High blood pressure and heart disease
Diabetes
Osteoporosis
Migraine
Hypocalcemia (low serum calcium levels)
Hypokalemia (low potassium levels)

Magnesium deficiency symptoms

The human body is smart and will start to signal when something is wrong or missing. It is our job to know how to listen to our bodies. However, it is important to remember that many of the symptoms listed below are not specific to magnesium deficiency, but can also be caused by other health conditions.

Possible symptoms of magnesium deficiency:

Muscle cramps or spasms
Fatigue and weakness
Loss of appetite
Nausea and vomiting
Abnormal heart rhythm
Abnormal eye movements (nystagmus or eye twitching)

Magnesium deficiency can occur in anyone, as our daily diet often does not include enough of the foods that contain the most magnesium, such as nuts, seeds, beans and oatmeal. People who suffer from magnesium deficiency are most at risk of developing it:

Digestive tract diseases (e.g. Crohn's disease, celiac disease)
Type 2 diabetes
Chronic alcoholism (~45% of people with chronic alcohol consumption suffer from magnesium deficiency)

Magnesium deficiency also increases with age, especially in people over 70 years of age, because with increasing age, magnesium absorption from the intestines decreases and excretion through the kidneys increases. Older people are also more likely to have chronic diseases and to take medications that further increase the risk of magnesium depletion.

Assessing magnesium levels is difficult because 50–60% of magnesium is located in bones and most of the rest in soft tissues. The most commonly used and easiest method to assess magnesium status is to measure serum magnesium concentration, although serum levels have little correlation with whole body magnesium levels or concentrations in specific tissues. The normal range for serum magnesium concentration is considered to be 0.75–0.95 (mmol)/L.

Different forms of magnesium and which one to choose

Magnesium comes in several different forms, each with its own absorption rate, pure magnesium content, and potential benefits. Let's take a look at the four best-selling magnesium supplement forms in Estonia and compare them based on the most important parameters.

Mg form	Bio- availability (absorption)	Solubility	Gastro- intestinal tolerance	Additional component benefits
Magnesium oxide	Very low (~4–10%)	Very low	Often causes diarrhea, gastrointestinal irritation	High pure magnesium content, but poorly absorbed
Magnesium hydroxide	Low (~5–10%)	Low	Used more as a laxative or antacid, often causes indigestion	Neutralizes stomach acid, poorly absorbed
Magnesium glycinate (bisglycinate)	High (~25–35%)	Good	Very well tolerated, minimal laxative effect	Supports sleep and the nervous system
Magnesium citrate	High (~25–35%)	Very good (water soluble)	Good, but in high doses may cause mild diarrhea	Good for muscle cramps

Why are magnesium oxide and hydroxide most commonly used in magnesium supplements in Estonia, when paradoxically their bioavailability, or absorption, is the lowest and there are no other advantages over other forms?

Unfortunately, people have very little knowledge that different forms of magnesium can have a big difference in both quality and the real benefits it brings to health. Unfortunately, many supplement manufacturers also take advantage of this. For example, magnesium oxide and hydroxide have been added to supplements, from which the absorption of elemental magnesium is very low. However, since the mass of the compound itself is large, it creates the illusion that it is a supplement very rich in magnesium. Magnesium oxide and hydroxide are added to supplements primarily because of their favorable price. The table below helps to better understand the above.

The package states	Necessary mass of Mg form to obtain 375 mg of pure Mg	Pure Mg in product	Bio-availability %	Absorbed from 375 mg of pure Mg
Magnesium oxide	625 mg	375 mg	4 – 10%	15.0 – 37.5 mg
Magnesium hydroxide	900 mg	375 mg	5 – 10%	18.7 – 37.5 mg
Magnesium glycinate (bisglycinate)	1500 mg	375 mg	25 – 35%	94 – 131 mg
Magnesium citrate	1250 mg	375 mg	25 – 35%	94 – 131 mg

A few additional observations on how to avoid falling victim to advertising when choosing a magnesium supplement:

The product packaging states “Magnesium diglycinate 650 mg”. This is a correct statement, as it refers to the total mass of the magnesium form, not the pure magnesium content. The magnesium content can be seen on the label on the back of the package. When looking at the package label, you may be surprised to find that instead of 650 mg of magnesium, the recommended daily amount (in one capsule) is actually only 90 mg of pure magnesium. Therefore, only 13.8% of magnesium diglycinate is elemental magnesium, which indicates a lower quality of the raw material.
Magnesium 375 mg. If the form of magnesium is not specified, then it is the elemental magnesium content. It is worth looking at the label on the back of the can to see which form of magnesium it is in order to understand how much magnesium the body will approximately absorb from it.

Therefore, if magnesium is listed with the amount, it is pure magnesium, and if the form of magnesium is listed with the amount on the packaging, the reference is only to the total mass of the form, in which case the magnesium content can be found on the back of the packaging.

How much, in what form and how to take magnesium?

Now look up the scale from under the bed and take a look at the numbers, because the body's daily magnesium requirement is 4.5–6.0 mg per kilogram of body weight. In addition to magnesium needs, age and activity must also be taken into account. As mentioned, magnesium absorption decreases in older age. In addition, physical activity causes fluid loss from the body. This also increases the need for magnesium consumption.

The European Food Safety Authority also outlined in its 2025 report the daily magnesium requirement according to age and average weight:

It is worth remembering that the optimal single dose of magnesium is 100-200 mg. That is why it is recommended to take magnesium in smaller doses and, if necessary, several times a day.

Too much magnesium from food does not pose a health risk to healthy people, because the kidneys remove the excess amount in the urine. However, problems can arise from excessive doses of magnesium from supplements or medications, which can cause diarrhea, which can also be accompanied by nausea and stomach cramps.

When to take magnesium - morning or evening?

To decide whether to take magnesium in the morning or evening, you need to remind yourself and proceed from what the purpose of taking magnesium is.

Taking magnesium in the morning can help to start the day calmly and relieve pain, muscle tension and cramps.

Taking magnesium in the evening can have a calming effect on the body and mind. Studies show that taking magnesium can improve the quality of sleep in some people - especially those who suffer from insomnia. For a restorative sleep, you can take magnesium a few hours before going to bed.

For sports activities, you can take magnesium 30 minutes before or immediately after exercise to help the body restore magnesium levels in the body after sweating and reduce muscle pain caused by excessive lactic acid accumulation.

Magnesium B6 – a dynamic duo

If you have been looking for magnesium in the shelves of a home store or pharmacy, you may have noticed that magnesium often comes with vitamin B6. There is a good reason for this. Vitamin B6 supports the nervous system and the creation of neurotransmitters. In addition, vitamin B6 helps magnesium to be better absorbed and to work at the cellular level.

The cooperation of magnesium and vitamin B6 is helpful in:
Managing stress and chronic fatigue
Improving mood and mental health
Improving brain function
Improving sleep quality

Come and get to know ICONFIT's high-quality Magnesium B6 here .

Magnesium for children – should and when to give it?

Magnesium is a very important mineral for children's health and development, contributing to the development of bones and muscles, the body's energy production, the health of the immune system and the functioning of the nervous system. Children should get their daily magnesium needs covered from a balanced diet, but sometimes they can also suffer from magnesium deficiency. However, it is worth consulting a family doctor or nutritionist before giving them magnesium-containing supplements.

It is interesting to know that several different scientific studies highlight a possible connection between magnesium deficiency in the body and attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children.

For example, in a 2019 review of several studies, lower levels of magnesium in plasma, serum, whole blood and hair were observed in children with ADHD.

Magnesium in food and the best natural sources of magnesium

Ideally, all the magnesium we need could be obtained from a healthy daily diet (such as the Mediterranean diet), but unfortunately we do not live in an ideal world. According to nutritionist Artur Minenko, many people do not get the magnesium they need due to refined foods, caffeine, and stress.

But you can still breathe easier, because the choice of magnesium-rich foods is wide. However, it is worth remembering that the body usually absorbs about 30–40%, and according to some sources up to 50% (EFSA 2015, NIH ODS 2022) of the magnesium consumed with food.

Check out the table below and find out what to choose for your daily diet to get the maximum amount of magnesium from food.

Food item	Mg content (mg/100 g)	Average absorption (%)	Actual available Mg (mg/100 g)
Pumpkin seeds	~535 mg	~35%	~187 mg
Sunflower and sesame seeds	~325–350 mg	~35%	~114–123 mg
Cashews and almonds	~260–270 mg	~35%	~91–95 mg
Cocoa powder (unsweetened)	~500 mg	~30%	~150 mg
Dark chocolate (70–85%)	~230 mg	~30%	~69 mg
Soybeans (dried)	~280 mg	~40%	~112 mg
Oatmeal	~140 mg	~40%	~56 mg

*The table was compiled using the USDA FoodData Central, EFSA/Europe, British NHS and Finnish Finel databases.

Several factors affect the absorption of magnesium from food.

Factors with a positive effect:

Organic acids (e.g. citric acid, malic acid) → improve solubility and absorption.
Proteins (e.g. animal protein, milk protein) → can promote absorption.
Vitamin B6 → supports intracellular transport.
Vitamin D → can indirectly support mineral metabolism.

Factors with a negative effect:

Phytates (in cereals, legumes) → bind magnesium and reduce absorption.
Oxalates (spinach, beets) → bind magnesium into an insoluble complex.
High doses of calcium → can reduce Mg absorption in competition, although the effect is usually small if intake remains within normal limits.
Coffee and alcohol → promote urinary loss of Mg, not so much a decrease in absorption.

We all drink more or less water every day, and the good news is that even regular tap, bottled, and mineral water can contain magnesium, but the amount depends on the specific water source and, in the case of bottled water, the brand.

We hope this blog post gave you a good overview of why magnesium is so important for both body and mind. I believe we all want healthy bones, a healthy nervous system, restorative sleep, and to feel mentally and physically energetic. Consciously choose magnesium-rich foods for your diet, but if you can’t think of everything yourself, then take a magnesium supplement that best suits your needs.

Sources:

Previous article Importance of Omega-3 Fatty Acids in Our Body

Next article Vitamin D – why is this sunshine vitamin so important for us?