We often consider magnesium, as the “magic” or the “missing” mineral in the body. This is especially true considering that most tested metabolic panels do not have magnesium as one of the tests. If you have to check your magnesium levels, they need to be specially ordered separately.
But this raises some important questions: what is a normal magnesium level? And does a normal blood magnesium level tell the whole story about total magnesium stores in the human body? And if they do correlate, are those magnesium stores within the body available at the tissue level to have a positive effect on performance?
Magnesium supplements have been used to enhance some exercise performance. Some athletes swear by it. Recently, we studied the effect of magnesium-rich electrolyte formula, MAGNAK, on reducing muscle cramps in athletes who were engaged in a half marathon on a hot summer day. Not only was it highly effective, but it also allowed multiple athletes to complete the race at a high altitude in the mountains of Tahoe. One limitation in that study was that levels of magnesium and other electrolytes were not measured during that race due to logistic issues. However, we would expect that even if a few athletes in that study had a normal magnesium level in the blood, the supplementation of a magnesium-rich formula did significantly reduce muscle cramps further indicating a role of magnesium in preventing muscle cramps.
WHAT IS A NORMAL MAGNESIUM LEVEL IN THE BLOOD
To understand this, we need to know some basic pharmacokinetics of this electrolyte. A normal magnesium level in the blood is considered to be above 1.7 mg/dl. This however, does not indicate a tissue level of magnesium in the body.
Magnesium is only about 1% free in the blood. The rest is bound to plasma proteins or distributed within different cellular components in the human body. Magnesium is absorbed via a paracellular transport from the gut and is influenced by transport of other electrolytes such as calcium for absorption. So, if the level of calcium in the blood drops, the levels of magnesium in the blood follow suit.
A normal level of magnesium is critical in those with cardiac conditions and those suffering from muscle cramps. A level of 1.8-2.0 mg/dl is usually considered normal in these situations. Supplements are often required in some individuals to improve blood magnesium levels particularly if a person is using some medications such as diuretics or those on chemotherapy.
These medications can significantly reduce magnesium levels in the blood (and the body). Chemotherapeutic agents such as cisplatin and carboplatin can cause gut injury and lead to magnesium loss through GI tract but also destroy magnesium channels specifically in the kidney preventing its reabsorption. In other words, chemotherapy will significantly change the normal magnesium levels into significant deficiency. Hence, these patients always require magnesium supplementation using tablets, electrolyte mixes such as HuMOLYTE or at times, intravenous magnesium sulfate.
A LOW MAGNESIUM LEVEL IN THE BLOOD
As mentioned above, in addition to diuretics, chemotherapy and alcohol, a low magnesium intake can lead to profound magnesium deficiency if left uncorrected. A critical piece of study done in 2014 using NHANES survey indicated that only 48% of American adults get the recommended dietary intake of magnesium. This indicates that due to food habits, packaging, or a general depletion of magnesium from the soil, the deficiency of magnesium from food is a critical issue and leads to numerous cardiovascular stressors that have a bad impact in the society.
If the blood magnesium level is mildly reduced, it is usually indicated by a laboratory value of 1.4-1.6 mg/dl. If the individual does not have symptoms of cramps, palpitations or weakness, these can be easily treated with oral supplements.
If the magnesium level in the serum falls below 1.3 mg/dl, an intravenous infusion may be needed. This is often seen in patients on chemotherapy or those with gastrointestinal disorders such as long-term diarrhea.
In patients where the magnesium level is < 1.1 mg/dl, patients usually require intravenous magnesium sulfate through an inpatient setting (ER or urgent care). Up to 4 grams of IV magnesium sulfate can be given in a single dose setting over 90-120 minutes.
MAINTAINING A NORMAL MAGNESIUM LEVEL- Why it’s important
In athletes, the requirement of magnesium is quite higher than normal adults. Typically, an endurance athlete requires about 600 mg of magnesium on a daily basis and in many cases, just food cannot provide this.
Athletes hence almost always resort to magnesium supplements- either magnesium citrate, glycinate or oxide. However, magnesium in these complexes is trapped and is in a tablet form, which requires your gastric juices to break it down into small elements which can then be absorbed. This process does not always work well as many of these salts in a complex form induce diarrhea. In general, magnesium absorption in many adults remains poor.
This has led to the creation of magnesium-rich powdered electrolyte mixes, such as MAGNAK. This electrolyte mix utilizes magnesium citrate, which is probably the easiest of the magnesium salts that can be absorbed through the GI tract.
The powder allows immediate absorption of the elemental magnesium with an additive or an amplified effect on absorption of other electrolytes, potassium and sodium, using a patented method called Nutrient Co-transfer Technology.
Maintaining your blood magnesium levels in the normal range has tremendous advantages on reducing fatigue, muscle cramps and palpitations during exercise. It is generally accepted that improving blood magnesium levels can correlate with improving overall tissue stores of this critical electrolyte. This allows individuals to focus on healthy living and working out more without the fear of cramping or feeling sore and tired afterwards.
