Magnesium is a mineral that performs a number of tasks inside your body, including supporting energy production and regulating your blood levels of other types of nutrients. If you take too much supplemental magnesium, you can eventually experience a deterioration of your normal kidney function. Kidney problems related to magnesium stem from another symptom of excessive intake called hypotension, or low blood pressure.
Background
Your body needs magnesium to initiate more than 300 chemical processes, including the breakdown of fats and carbohydrates and the creation of a main source of internal energy called adenosine triphosphate, or ATP. You also need magnesium to form DNA, RNA and your internal supply of proteins. Dietary sources of the mineral include leafy greens, unprocessed nuts and grains, milk and meat. Supplemental forms of magnesium include the laxative and antacid ingredient magnesium hydroxide and the laxative ingredient magnesium sulfate, as well as magnesium gluconate, magnesium citrate, magnesium chloride and magnesium lactate.
Hypotension and Kidney Symptoms
You can't develop toxicity problems from eating too much magnesium in food, according to the National Institutes of Health's Office of Dietary Supplements. However, you can develop problems from taking too many magnesium supplements or from taking very high doses of antacids or laxatives that contain the mineral. If your blood levels of magnesium rise too high, you can develop abnormally low blood pressure. Kidney effects related to excessive magnesium intake typically appear in cases of severe low blood pressure, along with additional symptoms that include heartbeat irregularities and lethargy. Potential kidney-related symptoms of hypotension include changes in your normal urine output, dehydration, nausea, vomiting and confusion.
Pre-existing Kidney Problems
Normally, your kidneys help remove excess magnesium from your body. However, if you have pre-existing impairments in your normal kidney function, they won't be able to perform this job efficiently, and you will have a higher risk for problems related to magnesium supplement intake, Oregon State University's Linus Pauling Institute reports. In these circumstances, even moderate intake of magnesium-containing antacids or laxatives can trigger magnesium toxicity. In addition to degradation of your normal kidney function, potential symptoms of magnesium toxicity include diarrhea, breathing difficulties, muscle weakness and cardiac arrest.
Maximum Safe Intake
The National Academy of Sciences' Institute of Medicine has established guidelines for maximum safe intake of magnesium supplements. Adults and children age 9 and older can take as much as 350 mg per day. Children between the ages of 4 and 8 can take as much as 110 mg per day, while children between the ages of 1 and 3 can take as much as 65 mg per day. In their first year, infants should only receive magnesium from food sources or formula. Consult your doctor for more information on the potential effects of magnesium toxicity, especially if you have kidney problems.
