What’s the upper safe magnesium dose from supplements?

Although there isn’t an upper safe limit of magnesium from food, high doses from dietary supplements may cause adverse effects. In fact, the maximum safe dose of magnesium from supplements is 350 mg.

Health benefits of magnesium

Magnesium is the fourth most abundant mineral in the body. It’s crucial for health, as it has several functions in the human body. For instance, magnesium acts as a cofactor for more than 300 enzymes and plays a key role in DNA synthesis! 

Moreover, magnesium is involved in energy production, glycemic control, protein synthesis, myocardial contraction, and blood pressure regulation. Hence, magnesium can play a therapeutic and preventive role in several conditions such as diabetes, osteoporosis, bronchial asthma, preeclampsia, migraine, and cardiovascular diseases.[1,2]

Also, magnesium plays a key role in nerve transmission, muscle contraction, muscular relaxation, bone development and mineralization. After all, almost all magnesium is stored in bones and muscles.

Low levels of magnesium are a common cause of cramps. Athletes should be extra cautious about getting adequate amounts of magnesium. Along with calcium and potassium, magnesium is key for muscle contraction, conduction of nerve impulses, and heart rhythm.

Furthermore, magnesium might protect from oxidative stress, as it’s necessary for the synthesis of glutathione, which is a powerful antioxidant.

Last, people who want to lose weight should get high doses of magnesium as well. It regulates glucose metabolism, prevents fluid retention and muscle loss while cutting down calories.

What’s the recommended daily intake?

The recommended daily intake of magnesium is 400-420 mg and 310-320 mg for men and women, respectively. Adults older than 30 years need slightly more magnesium.

Moreover, pregnant and lactating women need about 360 mg and 320 mg, respectively.

Children need much lower doses a day.

What’s the maximum dose of magnesium I can safely take a day?

Actually, there isn’t a maximum safe dose of magnesium from food. We can’t get overdose from diet. Healthy people excrete excess magnesium in the urine.

But, excess magnesium from dietary supplements can cause adverse effects. Thus, the Food and National Board has established an upper safe dose of magnesium from supplements.

In fact, the maximum safe dose of magnesium for healthy adults, teenagers, and children older than 9 years is 350 mg, while it’s only 110 mg for 4-8 years old children.

These upper safe doses stand only for dietary supplements. We can get higher doses from food.

Side effects of exceeding the daily upper dose of magnesium from supplements

Diarrhea, nausea, abdominal cramps, and facial flushing are the most common adverse effects of excess magnesium from dietary supplements.

If you have a sensitive stomach, you better avoid certain magnesium forms, such as carbonate, chloride, gluconate, and oxide. They are more likely to upset you.

On the other hand, magnesium in the aspartate, citrate, and lactate forms is better absorbed.

Furthermore, extremely high amounts of magnesium may cause severe side effects, such as vomiting, sleepiness, muscle weakness, depression, extreme low blood pressure, irregular heartbeat, and more.

People with impaired renal function should be cautious before taking magnesium supplements. The kidneys can’t remove excess magnesium as effectively.

In any case, you should consult your physician before taking any supplement.

Do I need dietary supplements containing magnesium?

Certainly, healthy people can get more than enough magnesium from food. Especially, if we consume foods rich in magnesium, such as seeds and nuts.

Unfortunately, approximately half of the US population consumes less than the required amount of magnesium. Poor diet is the main reason of low magnesium intake.[3]

Furthermore, soil is depleted of minerals, due to modern intensive agriculture technics. Hence, crops contain less magnesium than they used to be.

Also, processed foods and demineralized water contribute to magnesium deficiency. Actually, about 10% of the daily magnesium requirement is derived from water.

Do supplements exceed the maximum daily safe dose?

Supplementation could be beneficial for people with low levels of magnesium.

Most dietary supplements contain 100-1,000 mg of magnesium per tablet. Hence, many dietary supplements exceed the upper safe dose of magnesium.

As a rule of thumb, you shouldn’t exceed the maximum daily dose of 350 mg. You could take higher doses, only if your physician consult you so.

You can find a wide variety of magnesium supplements on Amazon.

Can I get too much magnesium from food?

In fact, there isn’t a maximum dose of magnesium from food. In contrast, eating foods high in magnesium is the safest way to boost magnesium intake.

Following a well-balanced, plant-based diet can significantly increase your magnesium intake. As a rule of thumb, foods high in dietary fiber, are high in magnesium as well.

Green vegetables, seeds, nuts, legumes, and whole-grain cereals are the best dietary sources of magnesium.

The richest common food in magnesium is pumpkin seeds. 1 oz has 168 mg, or 40% of the recommended daily intake!

Banana is among the most consumed fruits worldwide, which is particularly rich in magnesium as well.

Moreover, you better prefer whole-grain products. The germ and bran are the richest parts in minerals, such as magnesium. Hence, refined grains have substantially less magnesium.

Our bodies absorb about 30-40% of the magnesium of foods. For increased absorption rates, you should have high levels of vitamin D. Vitamin D can stimulate intestinal magnesium absorption. On the other hand, magnesium is required for the metabolism of vitamin D in the liver and the kidneys, and for its transportation in the serum.