In my practice as a transplant nephrologist, many of my kidney transplant patients can have a deficiency in magnesium, due to medications that prevent their bodies from rejecting their new kidney.
Magnesium is an important mineral in the body, helping with muscle, nerve and heart function, and in the production of energy. Magnesium also helps keep your bones strong and healthy. Having low levels of magnesium over a long period of time can increase the risk of high blood pressure, heart disease, type 2 diabetes mellitus and osteoporosis.
Low levels usually don’t cause any symptoms, but if this persists, early signs of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, cramps, seizures and abnormal heart rhythms can occur. Severe magnesium deficiency can lead to other mineral and electrolyte imbalances, such as low calcium and potassium levels.
There some conditions that can also make patients prone to low magnesium levels. These include those with chronic diarrhea, prolonged use of proton pump inhibitors for heartburn (typically more than a year), heavy alcohol intake and diuretic use. Intake of certain medications for infections and cancer treatments can also cause magnesium levels to drop.
Before you reach for a magnesium supplement, you should know that if you have a balanced diet and are in generally good health, you likely do not have a deficiency in magnesium. You just have to take a few servings of magnesium-rich foods per day to get the amount you need.
The Philippine recommended intake of magnesium for most adults is around 210 to milligrams per day. Good food sources are whole grains such as brown rice, whole wheat pasta and oats. For vegetables, green leafy ones such as kale, spinach, okra and chard are some examples, providing around 80 milligrams of magnesium per half a cup serving. Fruits include bananas, grapefruit, and avocados. Other magnesium rich foods include chickpeas, white beans, kidney beans, lentils, mixed nuts and sesame seeds, about 35 milligrams for half a cup. Eating a medium-sized potato with the skin can provide around 40 milligrams of magnesium.
In healthy persons it is difficult to get too much magnesium from food because the kidneys eliminate the excess in the urine. However, high doses of magnesium from dietary supplements can result in diarrhea, nausea and stomach cramps. Diarrhea is commonly reported with these forms of magnesium: magnesium carbonate, chloride, gluconate, and oxide. Magnesium supplements can also interact with other medications. If you take magnesium supplements take them at least two hours apart from other medications.
Be careful when taking magnesium-containing laxatives and antacids. Very large doses of more than 5,000 milligrams/day of magnesium can cause magnesium toxicity and even death. Symptoms of magnesium toxicity can include nausea, vomiting, low blood pressure, muscle weakness, difficulty breathing and an irregular heartbeat, and cardiac arrest. Patients with kidney problems or kidney failure are at high risk for this toxicity because their kidneys have lost the ability to get rid of the excess.
When taken properly, supplements can help you stay healthy. But supplements taken unnecessarily or incorrectly can do more harm than good. If you suspect that you could have a low magnesium level, consult your doctor first. A simple lab test can check your levels, and your doctor can prescribe the amount that is right for you.