Hypomagnesemia: low level of magnesium in the blood

There is talk of hypomagnesemia when the amount of magnesium in the circulating blood is less than considered normal. Normal blood magnesium values ​​range between 1.7 mg / dL and 2.2 mg / dL.

There are some variations depending on the laboratory that makes the measurement to determine normality. However, based on these figures, it is established that there is hypomagnesemia when laboratory results are less than 1.7 mg / dL.

Magnesium is a cation, that is, an element with a positive electrical charge. Among the cations of the human body, it is the most abundant outside the cell. Within the cells it is the second most abundant, after potassium.

As for the tissues where it is present, most magnesium is in the bone. Twenty percent is located in the muscles, secondly, and then the rest is distributed in the other organs.

The amount of body magnesium it is regulated as a balance between what enters with food and what is eliminated with urine. Approximately, in a normal and varied diet, enter 360 mg of magnesium. That amount is sufficient to sustain the normal functioning of the organism.

The foods that contribute the most magnesium to the human body are cereals in general, nuts and legumes. There is also magnesium in green leafy vegetables and in seafood, such as shellfish.

Causes of hypomagnesemia

Basically, we can talk about four main causes of hypomagnesemia:

  • Less admission to the body: It is a rare and uncommon cause of hypomagnesemia. When magnesium intake decreases, it is difficult for the renal system to retain the little that was circulating. It can occur when there are states of malnutrition or chronic alcoholism. Similarly, in people who are fed parenterally and not orally, hypomagnesemia is an adverse effect.
  • Major losses: If the digestive system is not able to retain and absorb the magnesium that enters with food, hypomagnesemia will also be generated. A diarrhea, for example, could cause less absorption.
  • Hyperparathyroidism: People who suffer from this pathology are affected by what is known as redistribution of magnesium. In the absence of parathormone deficiency, the metabolism of various substances, including magnesium, is affected. In that state, the magnesium that could be circulating is retained by the bone and is not present in the blood.
  • Renal dysfunction: As the balance of magnesium depends on your renal excretion, when there are pathologies of the kidneys there may be hypomagnesemia. There is, in particular, a genetic condition known as Gitelman syndrome, in which children are born with an alteration of the renal tubules that prevents them from retaining potassium, calcium and magnesium.

Read on: Nutrition and kidney failure: everything you need to know

Symptoms of hypomagnesemia

In most clinical cases, hypomagnesemia does not generate symptoms by itself.. In reality, what is evident are signs caused by other associated substances. The main generator of symptoms is the lack of potassium that leads to hypomagnesemia.

Once the body is deficient in magnesium and potassium, calcium is very likely to decrease as well. So, hypocalcemia adds to the generation of symptoms.

He clinical picture It can consist of:

Keep discovering: Potassium: regulation and functions


If the hypomagnesemia is not severe and is only detected in a routine laboratory analysis, the treatment is simple. The indication will be a diet with foods rich in magnesium, in the first instance. Then, the underlying cause of the alteration will be sought.

If, despite the diet, there is no improvement in blood magnesium values, supplements will be used. It will always be preferable to administer the supplements orally. There are some preparations of magnesium chloride or magnesium lactate that can be taken.

The parenteral route of magnesium application is for severe cases with symptoms that affect the quality of life. You can also opt for it in those patients who cannot use the oral route, for example, for digestive surgeries.

In chronic alcoholic persons with hypomagnesemia, the parenteral route is also preferred.. In this way, the application is assured before a patient who will hardly comply with an oral treatment.

If hypomagnesemia is accompanied by low potassium or low blood calcium, these should also be treated. Ideally, all substances be supplemented at the same time. It is known that if a single value is improved, for example potassium, without correcting the others, the effect is not lasting.

So, if you have been detected a low value of magnesium in the blood, do not worry. The medical professional will indicate a diet and, perhaps, a supplement. With the simple fulfillment of these measures, the alteration will disappear.