From the tests that I see in my office I often see that many clients bring me tests that show magnesium levels in the blood. The amazing thing is that while studies point out time and time again that only a small percentage of people get enough magnesium from their diet, I have never seen any tests that show that magnesium in the blood is lower than normal.The main reason this happens is simply because blood magnesium tests do not reflect actual magnesium in the body. This is not unusual, since this is also true for calcium. That is, it is not possible to know how much calcium is in the bones by measuring the calcium in the blood. This is why we see people with many osteoporotic fractures and severe osteoporosis having no calcium deficiency in the blood. Coming back to magnesium, we must first say that 60% of the magnesium in our body is in the teeth and bones, while the remaining 40% is inside the cells. It is estimated that the blood contains less than 0.3% of the magnesium present in the body, so by measuring the magnesium there it is impossible to understand how much magnesium is in the body unless there is a severe magnesium deficiency. Only in this case is this examination useful. But Magnesium is necessary for many functions. Therefore, there must be a way to know that the body has enough magnesium. An alternative and somewhat better way to measure if magnesium level in the body is adequate is the calcium ,magnesium ratio. It is most likely that in addition to magnesium, you will also find calcium in your blood test. In this case all you have to do is divide the calcium by the magnesium and get the ratio. If the result is between 3.91 and 4.7, the ratio is good and we consider that you are consuming a sufficient amount of magnesium. If the ratio exceeds 4.7 then we consider that magnesium consumption is low and you should increase it. Let's give some examples. You see on your tests calcium is 9 and magnesium is 2. All you have to do is take a calculator and divide 9 by 2. The result is 4.5 which is within the normal range we have set that is up to 4.7. Let's look at another example. Let's say calcium is 9.5 and magnesium is 2. Dividing it shows that the ratio is 4.75 and thus more than the 4.7 we have set as acceptable, so you need to increase your magnesium consumption.Search your latest blood tests. It is very likely that you will find both magnesium and calcium in it. Spend the minimum time necessary to get the result and find if your diet is sufficient in magnesium. On the other hand, those who are not impressed with half-measures and want to get a little closer to measuring magnesium with greater reliability, can measure magnesium inside the cells. We said earlier that 40% of the magnesium in the human body is inside the cells and there is a blood test that measures magnesium inside the cells. The cells that are most accessible to the blood test are the erythrocytes, that is, the cells that are present in the blood. It is therefore possible in some diagnostic centers to examine intracellular magnesium, which is a more reliable way to find magnesium in the body. To find which centers do this test near where you live or work, just do an internet search for "intracellular magnesium". The test is not expensive and some of you may find it useful and necessary to do it. The procedure is the same as any blood test, as long as the person doing the blood draw knows this test and puts the sample in the appropriate vials. Intracellular magnesium should range between 4.2-6.8 mg/dL, although many experts believe that the ideal intracellular magnesium should be above 6. Finally, those who are prepared to go far out of their way and their daily lives to ensure that magnesium consumption in their diet is sufficient can measure magnesium in hairs. This test is almost never available alone, but is typically done along with a test for salts, trace elements, and heavy metals. It's a test that most people have never heard of, and most doctors certainly haven't, and it's usually recommended in cases where we think someone has been exposed to heavy metals in the recent past. I emphasize that it is an exam that most people will never do in their life, but I mention it mainly for the completeness of the article. As a physician, I believe that the best way to ensure magnesium adequacy is to make sure to consume foods that are rich in magnesium. In the doctor's office when the history I see that someone consumes a large amount of green foods every day, especially green foods that are in the form of leafy vegetables such as lettuce, spinach, arugula, kale, collard greens and other greens, then I am sure that magnesium consumption is sufficient. If this is not the case, then I make sure in my nutritional guidelines to include and emphasize the importance and need to increase these foods and ensure they are done daily.