Magnesium daily intake dosage in the UK and Europe
The European magnesium dosage recommendations are made by the EFSA (European Food Safety Authority). It doesn’t think it’s possible to work out average requirements. So instead, it gives magnesium dosages based on its estimate of how much magnesium healthy people eat each day, averaged across nine different European countries. Recommendations like this are called AI which stands for Average Intake.
These amounts refer to elemental magnesium. You will see a much higher number on your supplement label.
Scroll down to learn how to understand magnesium supplement labels.
How much magnesium is recommended daily in the UK?
|
For Adults |
Recommended Magnesium Dosage |
|
For men |
350 mg per day |
|
For women |
300 mg per day |
|
Magnesium Dosage For Children |
|
|
For children aged 1 to 3 years, for both sexes |
170 mg per day |
|
For children aged 3 to 10 years, for both sexes |
230 mg per day |
|
For boys aged 10 to 18 years |
300 mg per day |
|
For girls aged 10 to 18 years |
250 mg per day |
|
Magnesium Dosage For Babies |
|
|
For infants aged 7–11 months |
80 mg per day is estimated |
|
Magnesium Dosage For Pregnant and Lactating Women |
|
|
In Europe, the recommendation is that the same magnesium dosage is set for pregnant and lactating women as it is for non-pregnant, non-lactating women. |
300 mg per day |
SOURCE: EUROPEAN FOOD SAFETY AUTHORITY
The obvious weakness in this method is that it focuses on how much magnesium people are getting, rather than the ideal amount they would need to be as healthy as they can be.
It also focuses on the average healthy person: But lots of people aren’t average, and the amount of magnesium we need varies a lot depending on other factors. They can include illnesses or medicines that get in the way of our ability to absorb magnesium, and hobbies and conditions that mean our bodies use it up faster than average.
Magnesium daily intake dosage in the USA
American recommended doses of magnesium are calculated differently, and this is probably why they’re higher than those in Europe. For adults, the Americans recommend about 25% more magnesium per day than the Europeans.
USA Recommended Dietary Allowances (RDAs) for Magnesium
|
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 |
410 mg |
310 mg |
350 mg |
310 mg |
|
31–50 years |
420 mg |
320 mg |
360 mg |
320 mg |
|
51+ years |
420 mg |
320 mg |
SOURCE: NATIONAL INSTITUTES OF HEALTH
How dangerous is too much magnesium?
The first thing to say is that there has never been a case of magnesium overdose from magnesium supplements, ever. The only way to get an overdose or cause actual harm is by having magnesium put directly into the blood stream. This is clearly an issue for medical professionals and not within the scope of this article!
Why is eating “too much” magnesium not dangerous? There are two reasons. Firstly, our kidneys eliminate excess amounts of magnesium when we pee. Secondly, if we eat too much magnesium it doesn’t get absorbed, and so we just pass it out when we open our bowels.
The downside, though, is that taking more magnesium than we can absorb tends to give us tummy upset. It can cause diarrhoea and – if it gets really bad – nausea and cramps. How does this happen? The magnesium salts (or compounds) draw water into our intestine, which is exactly the same way some types of laxatives work.
How much magnesium do we absorb from supplements?
The amount of magnesium we absorb from supplements varies a lot. Forms of magnesium that are organic – in other words, bonded to a molecule that is found naturally in plants or animals – are better absorbed.
Organic magnesium compounds
1 – Magnesium citrate: Magnesium salt of citric acid, a substance found in citrus fruits
2 – Magnesium gluconate: Magnesium salt of gluconic acid, which exists in small amounts in some fruits and wine
3 – Magnesium glycinate (or bisglycinate): Magnesium bound to two molecules of the amino acid glycine, a vital nutrient for our brains and mental health, sleep, muscle building and metabolism
4 – Magnesium lactate: Magnesium bound to lactic acid, a substance our muscles make to generate energy
5 – Magnesium malate: Magnesium salt of malic acid, which is common in some fruits and wine
6 – Magnesium orotate: Magnesium bound to orotic acid, which occurs naturally in dairy foods and some root vegetables
7 – Magnesium taurate: Magnesium bound to the amino acid taurine, which is vital to create energy and for our nerves and brain, eye health and digestive juices
Inorganic magnesium compounds
1 – Magnesium oxide: Magnesium bound to oxide, resulting from the combustion of magnesium
2 – Magnesium carbonate: Magnesium bound to carbonate, the salt of carbonic acid
3 – Magnesium chloride: Magnesium bound to chloride, the salt of hydrochloric acid
4 – Magnesium sulphate: The compound of magnesium and sulphur is better known as Epsom salts or bath salts
We absorb magnesium in our small intestine. Researchers think we usually absorb 40–50% of the amount we eat, but there are variations from as low as 10% to as much as 70%.
How much magnesium can you absorb and what affects the dosage you really get
Things which improve magnesium absorption
You can increase the amount of magnesium you absorb by taking it with fruit and protein foods, with vitamins D3 and B6, and with zinc. You can also improve absorption by taking as many different magnesium compounds as possible, as they can be absorbed through multiple uptake pathways. Finally, we absorb organic magnesium compounds (such as glycinate, citrate and malate) better than inorganic magnesium forms such as magnesium oxide.
Things which reduce magnesium absorption
Foods and substances which can reduce magnesium absorption include phytic acid found in nuts and seeds; phosphate, which is hard to avoid because there’s a little in almost every food; and lots of dietary fibre. You are also likely to absorb less magnesium if you take just one type of magnesium compound – especially an inorganic form – as it will all be absorbed through a single uptake pathway.
Supplement labels: How much magnesium is in this, exactly?
Magnesium supplement labels usually give you a high number, which tells you the weight of the magnesium compound in the supplement. But they also have a much smaller number for the actual amount of magnesium in that compound: this is the elemental magnesium number.
Say, for example, you buy a magnesium supplement that says it contains 2000 mg of magnesium gluconate. How much actual magnesium is in this? The table below says 5%. So when you crunch the numbers, that means you would get 100mg of elemental magnesium from this supplement.
The amount of elemental magnesium in a supplement will be different if the supplement is buffered. By blending inorganic magnesium (such as magnesium oxide) with an organic magnesium compound, you can increase the total amount of elemental magnesium you take in, and boost the amount you absorb. This works because the different forms of magnesium are absorbed through different uptake pathways.
|
Magnesium Compound |
Elemental Magnesium Content (approximate) |
Absorption rate |
|
Magnesium citrate |
15% elemental magnesium |
Medium absorption |
|
Magnesium oxide |
63% elemental magnesium |
Low absorption |
|
Magnesium gluconate |
5% elemental magnesium |
High absorption |
|
Magnesium carbonate |
32% elemental magnesium |
Low absorption |
|
Magnesium malate |
15% elemental magnesium |
High absorption |
|
Magnesium glycerophosphate |
12% elemental magnesium |
Medium absorption |
|
Magnesium glycinate |
12% elemental magnesium |
High absorption |
|
Magnesium lactate |
12% elemental magnesium |
High absorption |
|
Magnesium orotate |
14% elemental magnesium |
High absorption |
|
Magnesium taurate |
9% elemental magnesium |
High absorption |
|
Magnesium aspartate |
10% elemental magnesium |
High absorption |
What if my magnesium supplement has too much for me?
You may have a magnesium supplement already and feel that it’s just too strong for you. If you’re not getting tummy upset, there’s really no need to worry.
You can easily lower your magnesium supplement dosage by taking fewer tablets or capsules each day than the recommended dosage. This will make the bottle last longer, and help you save money!
However, remember that the standard dosages are recommended for healthy people. Read on to make sure you’re not one of the special cases who need more magnesium than usual.
Who needs a higher magnesium dosage than average?
The dosage tables above apply to the average healthy person. The reality is, the amount of magnesium you need depends on a lot more factors than age and sex. The following groups are more likely than others to be at risk of not getting enough magnesium.
People with gastrointestinal diseases
People with chronic diarrhoea from Crohn’s disease, IBS, celiac disease and other intestinal diseases can gradually develop a magnesium deficiency. They therefore need more magnesium than average. Resection or bypass of the small intestine, especially the ileum, also typically leads to magnesium loss.
People with type 2 diabetes
People with insulin resistance or type 2 diabetes pee out more magnesium than average and often end up with a deficiency. Doctors think this is caused by having too much glucose in the kidneys, which causes people to produce more urine.
Alcoholics
Alcohol upsets the tummy, causing vomiting and diarrhoea, and it can damage the pancreas causing fat in the stools. All this will kick magnesium out of the body. Alcohol can also harm the kidneys and make you lose too much magnesium in the urine. Other knock on effects, including phosphate depletion, vitamin D deficiency, acute alcoholic ketoacidosis and liver disease, can all contribute to magnesium deficiency.
The elderly
Older adults typically eat less magnesium than younger adults, whilst the amount of magnesium they absorb goes down and the amount they pee out goes up. Older people are also more likely to have chronic diseases or take medications that increase their risk of magnesium loss.
People who take certain medicines
Various medicines reduce magnesium absorption, including:
- Biphosphates like Fosamax and medicines given for osteoporosis
- Tetracycline antibiotics such as demeclocycline (Declomycin) and doxycycline (Vibramycin)
- Quinolone antibiotics, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin)
- Diuretics Furosemide (Lasix) and bumetanide (Bumex), and thiazide diuretics, such as hydrochlorothiazide (Aquazide H) and ethacrynic acid (Edecrin)
- Proton pump inhibitor (PPI) drugs for gastritis and acid reflux, such as esomeprazole magnesium (Nexium) and lansoprazole (Prevacid).
