This article will explain how magnesium affects the body and how much is too much. It will also cover risk factors, symptoms, treatment, and when to seek immediate medical care.
A magnesium overdose, also called magnesium toxicity or hypermagnesemia, generally occurs when magnesium is ingested in large quantities as a supplement or medication, either as a pill or a liquid.
Magnesium is commonly found in over-the-counter medications. It is often used as a laxative. Some antacids also contain magnesium.
Symptoms including diarrhea, nausea, and abdominal cramping after taking a magnesium-base laxative or antacid may indicate
People with impaired kidney function are at the greatest risk for magnesium overdose. People with kidney disease are at risk for dropping blood pressure even with a moderate magnesium overdose.
Serious cases of magnesium overdose may cause:
- difficulty breathing
- mental confusion
- muscle weakness
- irregular heartbeats
It can also lead to cardiac arrest.
Magnesium is an essential mineral that helps muscles function and maintain energy. It helps build strong bones and regulates blood sugar, blood pressure, and nerve functions.
Magnesium also contracts muscles and maintains a natural heart rhythm. Kidneys naturally remove excess magnesium in your urine.
The Food and Nutrition Board of the Institute of Medicine and National Academies provides these
| Age | Male | Female | Pregnancy | Lactation |
|---|---|---|---|---|
| Birth to 6 months | 30 mg* | 30 mg* | ||
| 7–12 months | 75 mg* | 75 mg* | ||
| 1–3 years | 80 mg | 80 mg | ||
| 4–8 years | 130 mg | 130 mg | ||
| 9–13 years | 240 mg | 240 mg | ||
| 14–18 years | 410 mg | 360 mg | 400 mg | 360 mg |
| 19–30 years | 400 mg | 310 mg | 350 mg | 310 mg |
| 31–50 years | 420 mg | 320 mg | 360 mg | 320 mg |
| 51+ years | 420 mg | 320 mg |
It is very rare for a person with healthy kidneys to experience a magnesium overdose by consuming foods that have naturally occurring magnesium.
Plant and animal foods that are high in magnesium
- dark green leafy vegetables, such as spinach and swiss chard
- dried legumes and beans, such as baked beans, soybeans, lentils, and peanuts
- seeds and nuts, such as pumpkin seeds, almonds, peanuts, and cashews
- whole grains and oatmeal
- some breakfast cereals and other fortified foods
- meats including fish, poultry, and beef
- white potato with skin
- bananas
- raisins
- dark chocolate
- cow’s milk, yogurt, and soy milk
Magnesium may also be found in tap, mineral, and bottled water. The amount of magnesium depends on the source and brand of water. You can check the dietary label on the water bottle for the magnesium amount.
Magnesium supplements are another source of magnesium. These come in various forms, including:
- magnesium oxide
- magnesium citrate
- magnesium chloride
Be aware that the dietary supplement label lists the amount of elemental magnesium in the supplement, not the weight of the entire magnesium-containing compound.
Magnesium
If your doctor recommends a magnesium supplement, be sure to ask about the type and amount you need and any other products that may interfere with absorption.
Laxatives are another product that may contain magnesium. Some laxatives are high in magnesium, but the body may not absorb all the magnesium due to the laxative effect of the product.
Talk with your doctor about the most appropriate laxative for you. Tell your doctor if you experience magnesium overdose symptoms from taking laxatives.
Excess magnesium can cause a range of symptoms. These may include temporary nausea, abdominal cramping, and diarrhea to serious symptoms that may indicate a life threatening situation.
Symptoms of magnesium overdose
Excess magnesium most commonly produces diarrhea. Other symptoms are a drop in blood pressure that may occur with severe overdose. Magnesium toxicity symptoms
- abdominal bloating or distension
- abdominal cramping or pain
- diarrhea
- muscle weakness
- nausea and vomiting
- facial flushing
Serious symptoms that might indicate a life threatening condition
In some cases, a magnesium overdose can be life threatening. Seek immediate medical care (call 911) for any of these
- abdominal pain that can be severe
- difficulty breathing or rapid breathing
- irregular heartbeat (arrhythmias)
- urine retention
- muscle weakness
- dizziness, lightheadedness, lack of concentration (symptoms of a drop in blood pressure)
A magnesium overdose generally occurs with magnesium-containing laxatives or antacids taken in large doses involving more than
Magnesium overdose
Many factors increase the risk of developing magnesium overdose. Not all people with risk factors will experience a magnesium overdose.
Risk factors for magnesium overdose include certain kidney diseases and excess magnesium ingestion.
Always consult a healthcare professional before taking any magnesium-based supplements or medications.
Tips for lowering your risk of magnesium overdose, especially if you have kidney disease, include:
- Avoid magnesium-based antacids.
- Avoid magnesium-based laxatives.
- Follow the recommended dosages for magnesium supplements.
Treatment for magnesium overdose will vary depending on the severity of the overdose.
A doctor may recommend that you stop taking over-the-counter laxatives, antacids, or magnesium supplements for mild magnesium overdose symptoms.
In
- IV fluids and diuretics for a person without kidney disease
- kidney dialysis, for a person with kidney disease
- intravenous calcium gluconate
Complications of untreated or poorly controlled magnesium overdose can be serious, even life threatening in some cases. Complications of magnesium overdose
- cardiac arrhythmias (irregular heartbeats)
- difficulty performing daily tasks
- impaired balance and coordination
- respiratory failure and respiratory arrest
Here are questions people often ask about magnesium.
Is 1000 mg of magnesium too much?
The recommended dietary allowance (RDA) of magnesium for adults 19–51+ years is 400–420 mg daily for males and 310–320 mg for females (not pregnant or lactating). For more detail, see the RDA chart earlier in this article.
Overall, the tolerable upper intake level (UL) for magnesium supplements only is 350 mg for all adults. This maximum daily magnesium intake is not likely to cause harmful effects.
How long does magnesium stay in your body?
Research shows that the gut absorbs roughly
It is possible to overdose on magnesium. This typically happens when you get too much magnesium from supplements or over-the-counter medications. Rarely does it occur from ingesting foods that contain magnesium. Healthy kidneys will remove excess magnesium in the urine.
If you have kidney disease or ingest too much magnesium, you may be at risk of an overdose. Diarrhea is a common symptom of a magnesium overdose. Seek immediate medical care for symptoms of magnesium toxicity. Your doctor will recommend treatment based on the severity of the overdose.
