Understanding Magnesium Side Effects and Risks

Magnesium is a vital mineral found naturally in many foods. It supports various bodily functions such as protein creation, strong bone development, maintaining cardiovascular health, regulating blood pressure, nerve signal transmission, blood sugar control, and energy production.

The National Institutes of Health recommends adult men intake 400-420 mg daily, while women should aim for 310-320 mg. Food sources rich in magnesium include almonds, cashews, peanuts, spinach, and black beans. Excessive magnesium, known as hypermagnesemia, can cause health issues.

Learn about potential magnesium side effects below.

Digestive issues
High magnesium levels can cause gastrointestinal problems like diarrhea, as magnesium acts as a natural laxative. Overconsumption may result in watery stools, stomach pain, nausea, vomiting, and fatigue. The NIH recommends not exceeding 350 mg of magnesium from supplements daily.

Heart and blood effects
Excess magnesium can affect heart health, leading to low blood pressure (hypotension) that causes dizziness, lightheadedness, blurred vision, and fainting. It may also slow the heartbeat or cause irregular rhythms, sometimes resulting in cardiac arrest in severe cases.

Kidney complications
Kidneys usually remove excess magnesium, but impairment from conditions like chronic diabetes, alcoholism, or drug abuse can hinder this process. Elevated magnesium levels in such cases risk toxicity, which can worsen diabetes control and impair blood clotting — prompting doctors to advise against additional magnesium intake.

Breathing and neurological effects
Too much magnesium can impair lung function, leading to breathing difficulties, decreased reflexes, and drowsiness. Stopping supplementation often improves these symptoms.

If persistent symptoms occur, consulting a healthcare professional is essential for proper diagnosis and management.