Magnesium and Diabetes.

Magnesium (Mg) is a mineral that all the cells in our body need.

It is hard to find a metabolic action that does not require it. Without it hundreds of enzymes will not work properly. It is needed for the manufacture of protein, the formation of bone, the production of new cells, the making of ATP, the clotting of blood etc, etc.

What is important to us diabetics, both Type 1 and 2, is the fact that it also plays a major role in blood sugar regulation - a lack of Mg affects the pancreas's insulin secretion ability and also increases insulin resistance in the tissues.

An interesting aside here - I have heard that Metformin, one of the most common drugs used to treat Type 2 diabetes, raises magnesium levels in the liver, and yet another oral diabetic drug, Pioglitazone, increases the concentration of Mg in adipocytes (fat cells). This does tend to lend some credence to the advantages Mg has in treating diabetes.

People with diabetes tend to have lower magnesium levels, especially if the disease is not well controlled or has been uncontrolled for a long period of time.
It is thought that when the blood glucose levels go very high the kidneys lose their ability to retain magnesium, leading to excess excretion of magnesium in the urine (and we all know how often we had to visit the 'little room' prior to diagnosis and even now in some cases!).

The loss of magnesium in this way leads to low levels in the blood, called hypomagnesemia - not a word you can say after a few drinks!

Also insulin resistance decreases the cellular uptake of magnesium and therefor the intercellular levels become too low.

So what are the diabetic factors that may be affected by lack of magnesium?

1. Insulin resistance and blood glucose control.
Mg is needed for the making and secretion of insulin and also by the cells so they create more insulin receptors and therefore keep up their insulin sensitivity. The lack of Mg leads to insulin resistance and therefore high blood glucose.

There have been some queries as to whether this is a 'chicken or egg' situation. Did the disease come first or the deficiency? It appears to me to be a bit of a vicious cycle. Diabetes makes the deficiency worse while the deficiency aggravates the diabetes.

A study done in Mexico to see if they could improve BG control in diabetics by feeding them magnesium supplements appeared to show encouraging results. The group taking the magnesium had better fasting glucose levels and other diabetic symptoms also improved.

2. Hypertension.
There have been studies done that certainly point to a lack of magnesium being implicated in high blood pressure.

One such study, called DASH (standing for Dietary Approaches to Stop Hypertension) suggested that a diet high in magnesium, along with other minerals, could significantly lower high blood pressure.

The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure takes this seriously enough that it recommends "maintaining an adequate magnesium intake as a positive lifestyle modification for preventing and managing high blood pressure".

It is possible that Mg helps high blood pressure by relaxing the blood vessels, keeping insulin levels low and maintaining normal levels of potassium. When ones blood pressure is up ones cells tend to have high levels of sodium and low levels of potassium, factors that are usually controlled by the cell membrane 'pump'.

Magnesium is crucial to the 'switching on' of this pump and thus getting potassium into, and sodium out off the cells.

3. Cardiovascular problems.
It is thought that low levels of magnesium can cause cardiac arrhythmia (abnormal or irregular heart rhythms).

Likewise it can cause metabolic changes that can may add to ones chances of having strokes or heart attacks. As magnesium is involved in the breakdown of fatty acids a deficiency can cause increased triglyceride levels.

Magnesium's role in preventing blood clots, by stopping blood platelets from sticking together, is also a key part of it's prevention of cardiovascular disease.

4. Retinopathy.
A magnesium deficiency may hasten the progression of the deterioration of the eyes in diabetic retinopathy.

5. Pregnancy.
It has been suggested that Type 1 diabetic women who are lacking in magnesium may suffer higher rates of spontaneous abortion and birth defects.

6. Diabetic neuropathy.
Magnesium is involved in the way messages pass from nerves to muscles and organs and also the sensitivity of said nerves and muscles. Thus a lack can be implicated in neuropathy.

A study linked magnesium deficiency to foot ulcers, which are the result of neuropathy and peripheral vascular disease.

Can increasing your magnesium levels prevent diabetes?
It is very possible that if adequate magnesium levels are maintained one has less chance of developing insulin resistance and type 2 diabetes.

There have been a number of studies done, one by the Harvard School of Public Health, that found that the men and women who ate diets containing higher levels of magnesium were the least likely to develop type2 diabetes. This was no small test, it dealt with more than 127,000 people over an average of 15 years.

The second study, also done by Harvard, in combination with Brigham and Women's Hospital in Boston, USA showed that the results were even better for overweight women. Those who ate larger amounts of magnesium had a 22% lower chance of developing diabetes.

In what could be termed a 'reverse study' done in Mexico, patients who were already suffering from metabolic syndrome (insulin resistance and also possible hypertension & high cholesterol), which usually develops into type 2 diabetes, had much lower magnesium levels than subjects who did not have this syndrome.

These studies would appear to tell us that people with low levels of magnesium, especially if due to poor diet, are at greater risk of developing insulin resistance and type 2 diabetes.

How much magnesium is enough?
The present RDA (recommended dietary allowance) is as follows:-
1-3years olds need 80mg (milligrams).
4-8 year olds need 130mg.
9-13 year olds need 240mg.
14-18 year olds require the most, 410mg for males and 360mg for females.
Adults need 400-420 mg for males and 310-320 mg for women.

Studies are beginning to show up the fact that many of us are not getting enough dietary magnesium. In fact in the US the National Academy of Sciences and the Institute of Medicine (after great deliberation & research) say an estimated 50% to 85% of the U.S. population is receiving inadequate magnesium intake.

Why are we so lacking in magnesium?

This can be due to a number of factors;-
1. Diet.
One needs to look at the foods that contain the most magnesium and then ask yourself how much of these you eat.

Magnesium is found in greatest quantities in:-
Whole grains such as those used in bread, porridges (like maize meal and Maltabella, better known to our South African readers) and brown rice.
Legumes - lentils, beans, peas and Soya bean products.
Nuts and seeds. Pumpkin seeds have 402mg/100g and cashews have 255mg/100g.
Dark green vegetables - spinach (for eg. 1/2 cup of boiled spinach contains 65mg), broccoli, dark green lettuce (not the common Iceberg lettuce) and cabbage.
Avocado - 1/2 cup has 35mg.
Milk - 1 cup whole milk has 24mg.
Chocolate - black chocolate has as much as 228mg/100g. Now how is that as an excuse to indulge?!!!

One does not get many of these in our fish and chip, pizza and barbecue world (okay SA folk, I know it's really a braaivleis but am writing for the wider audience here!).

Mg can bind to other substances and thus be prevented from being absorbed in the intestine. Phosphorous and aspartame are two of those substances and where do we find large amounts of them - in our popular fizzy drinks, both regular and diet.

2. Food preparation.
We tend to eat a lot more refined and processed foods and these severely lack magnesium. To bring this home lets take a look at bread. Refined white bread has only 6mg of magnesium per serving while whole grain bread has 26mg per serving.

3. Agricultural practises.
The soils of many countries have been exhausted over the decades that they have been farmed. The fertilisers we are putting on do not contain much, if any, magnesium. The crops are becoming deplete in essential nutrients and thus inadequate to supply our needs. Even if we eat the correct foods we may still be receiving insufficient magnesium because the levels in the foods are so much lower than they should be.

4. Medications.
The use of certain supplements, such as calcium or Vitamin D, may increase your need for magnesium. It is for this reason that you will often see calcium supplements sold combined with Magnesium (Cal-Mag). Basically these minerals, plus potassium, appear to be tied together somehow and the need for one frequently indicates the need for another.

Aluminum, fluoride, & phosphate interfere with absorption.

Antibiotics like Gentamicin, and Amphotericin can cause deficiency.

Diuretics, for example Lasix, Bumex, Edecrin, and hydrochlorothiazide have been implicated in depleted levels of magnesium due to loss in the urine.

Certain cancer medications, like Cisplatin, also lower magnesium levels and radiation causes large losses of Mg.

And finally and most important to many diabetics, insulin treatment itself. The injecting of insulin can prevent magnesium from being metabolised properly.

5. Where you live.
This should, I suppose, come under diet but it is a little less general than that so I have separated it.

In certain countries of the world the intake of protein and that of alcohol is higher than in others. This can lead to a magnesium deficiency.

The ones that instantly spring to mind are South Africa, Australia and Texas, USA though there may well be others that fit into this category.

Then if you happen to live in a 'hard water' area you can, for once, count yourself lucky. Your water, that makes it so dashed difficult to get soap to foam and puts deposits on all your appliances, will contain more magnesium than soft water - a good reason to increase your water intake.

Proof of this came from a study done in Taiwan, where the chance of dying from diabetes was found to be inversely proportional to the level of magnesium in the drinking water. The Taiwanese also found that lack of Mg in the water related to a higher death rate from strokes and hypertension.

Likewise a study in Sweden showed that deaths from acute myocardial infarction were inversely proportional to the amount of magnesium in the drinking water.

See also -

6. Other diseases.
Disease that affect absorption of food, such as Crohn's disease or Celiac disease can also be responsible for preventing the body from taking up enough magnesium.

This can occur in any gastrointestinal disease.

Excessive vomiting or chronic diarrhoea can also cause a lack of magnesium.
Overactive thyroid or parathyroid glands tend to decrease Mg levels..

Alcoholism, which can also be termed a disease, results in low magnesium levels, possibly because so often alcoholics substitute alcohol for food and their high liquid intake results in Mg being voided in the urine. The levels are even lower in those going through withdrawal.

7. Age.
Depleted Mg levels at this time could be due to a more restricted or a 'reduced in quantity' diet or just due to the fact that for some reason the absorption of magnesium decreases with age while at the same time the kidneys excrete more.
It also relates to the above mentioned 'medication' reason, as the older one gets the more medications one seems to be given.

8. Stress.
When we are highly stressed the oxygen levels in the tissues decreases and this causes Mg to move out of the cells into the bloodstream leaving us with deficient intercellular Mg levels.

What does one do to increase one's magnesium levels?
The first thing to do is the obvious one - eat better. Plenty of leafy greens and unrefined foods will do the trick.

However there are problems attached to this ( and I do not just mean lack of inclination) if you are a diabetic, especially an overweight type 2.

If you are on a strict weight-loss diet it is very hard to get the required amount of magnesium from your food even if you live on green leafy stuff morning, noon and night.

I would also like to be a fly on the wall as some mom explains to her eleven year old that pizza is now out and raw spinach is in!!!

So that leads us to the next choice - Oral Supplements.

WARNING - people with kidney disease are not able to excrete excess amounts of magnesium so they should not take magnesium supplements unless prescribed by their doctor.

The first thing you need to understand is that oral supplements are like people - they are not all created equal.

This is very important folks, so pay attention.

To get the benefit of the medication it has to be absorbed and this is where the problem lies.

Magnesium is notoriously difficult to absorb and just to make things even more interesting this absorption rate decreases if you suffer from a lack of Mg - figures doesn't it!

Mg in oral Mg tablets come bonded to another substance, usually a salt, such as in Mg chloride, or an amino acid, as in Mg citrate. The suffix 'ate' usually means it is bonded to an amino acid.

So we get this whole list of Mg forms, for example Magnesium glycinate, Mg sulfate, Mg orotate, Mg aspertate, Mg oxide, Mg citrate, Mg malate, Mg chloride, Mg lactate, Mg carbonate etc, etc.

So which do we take?
First we need to educate ourselves.

Two terms that keep coming up when talking about magnesium supplements are elemental magnesium and bioavailability.

1. Elemental magnesium - the amount of magnesium in the compound - remember that tablets are rarely made up of a single substance.

2. Bioavailability - the amount of magnesium that is absorbed in the intestines and it's subsequent availability for use in the cells.

It is the combination of these two factors that contribute to how well the supplement works.

It is no good having a tablet that contains huge amounts of elemental magnesium if it is in a form that is not bioavailable.

Unfortunately the tablets that are readily available from the local supermarkets and online are, more often than not, Mg oxide.

This has one of the lowest bioavailability rates of any of the forms, but it is cheap to produce.

The normal consumer will naturally buy the pills that claim to have the most of the ingredient they are looking for and thus are more likely to buy the pot claiming to have 300mg of magnesium rather than the one claiming 80mg unless they know that the first contains barely absorbable Mg oxide while the second has a much better absorbed form of Mg. You see the need to educate yourself?

Maybe it is because I did just the above, i.e. bought pills before really finding out all the details, and am now stuck with a useless pot of Mg oxide tablets, that makes me so determined that others will not be caught in the same way.

The one I would look out for is Mag-Tab SR, made by Niche Pharmaceuticals. These contain Magnesium L-lactate dihydrate. This has been tested in clinical trials and appears to have the best bioavailability and a very low incidence of side effects.

The tablets are sustained release ones which means the magnesium is around in small amounts over a long period so the body does not get it in one burst, use what it needs and then tosses the surplice away in the urine.

It can be bought online from or from Niche itself. (see below)

I have been unable to find it sold anywhere outside of the US so if, like me, you are determined to get the best, you will have to order it from there. It does push the price up though.

Niche Pharmaceuticals website is worth looking at as it contains interesting information on magnesium and it's supplementation.

My second choice would be SlowMag made by Purdue Products. These contain Magnesium chloride , which is also highly bioavailable. The sustained release tablets are enteric-coated to help prevent stomach upset and also contain calcium.

I believe that there are two generic forms of SlowMag, called MagDelay or Mag64.

Magnesium Malate is a compound of magnesium and malic acid. It's bioavailability is not bad and it does appear to be more widely available. I actually managed to find somewhere in the UK that sold it, -

What are the suggested doses for oral supplements?
Again this varies from 300mg to as much as 2000mg daily for a therapeutic dose, usually divided into 2-3 doses so as to avoid possible diarrhoea.

Magnesium's one major problem when taken orally is its laxative effect. There are various forms that try to address this, such as time release tablets. High doses should only be taken under medical supervision.

For normal folk who feel they may be lacking Mg or for pre-diabetics a dose of 400mg a day should be enough.

For us with fully developed diabetes 800mg may be a better dose, taken twice a day.

Fortunately, for folk with no kidney problems, any extra Mg will just be passed from the body in the urine. This may give you expensive urine but it will not damage your health.

Mg can also be absorbed through the skin, known as transdermal application.
See -

You may have read alternative medicine sites advocating Epsom salt baths. This is because Epsom salts are actually Mg sulfate (sulphate if you use the English spelling), which you are absorbing through your skin. It is great for treating muscle and nerve problems.

Mg chloride is another readily absorbed form that can be mixed with water to make a skin lotion.

I have been told that Mg levels can be raised much faster by this method but as usual have been unable to find Mg chloride in the UK. Our US friends will be more lucky, it can be bought from

Finally, if your levels are low enough to be causing you serious problems, then there is the chance your doctor may prescribe intra-muscular or intravenous injections.

The latter are preferred as the intra-muscular ones are known to be painful.

Intravenously, hospitals give magnesium sulfate or Mg chloride. This is often one of the first treatments given when folks are brought into hospital with a stroke or heart attack and I believe there is talk of allowing paramedics to administer it so the patient gets it even earlier.

Risks of taking Magnesium.
Getting all the magnesium from your diet is totally free of risk. Taking it in the form of supplements can cause diarrhoea and nausea.

Too much Mg can result in both of the above plus muscle weakness, mental confusion, hypoglycemia, irregular heartbeat and difficulty breathing.

As stated before people with normal kidney function will have no problem with Mg supplementation but if you have any form of kidney dysfunction or even the possibility of this, which tends to hinder the excretion of mineral salts, you should NOT take Mg supplements without consulting your doctor.

Remember the older you are the more chance you have of problems in this area because kidney function naturally decreases with age.

How are levels of magnesium measured?
Unfortunately there is no easy answer and this is why Mg deficiency is so hard to determine.

One would think that a simple blood test would be okay, however only 1% of the body's Mg is found outside the cells, i.e. in the serum, and this gives no idea of what the levels are within the cell, and those are the important numbers. The body like homeostasis and so will remove Mg from the cells to keep that of the blood at 1%, thus Mg does not show low levels in the blood serum until it is severely depleted inside the cells.

So blood tests are not sensitive enough to confirm Mg deficiency or not. An abnormal test result is great (in the terms of your getting help, not for your health) but a normal one does not mean that you are not cellularly deficient, so it is not much use.

The serum tests are none the less done to confirm seemingly obvious cases of Mg deficiency, as determined by symptoms and medical history.

The normal ranges are not well established but for serum Mg a range of 1.8-3mg/dL (1.5-2.5mEq/L - milliequivalents per litre) for adults is accepted as 'normal'.

Then one can do a Magnesium Retention Test, which involves taking a urine sample, then injecting two ml of 50% MgSO4, waiting 24 hours and taking another urine sample. The samples are tested for magnesium and creatinine. If more than 25% of the injected Mg is retained then one is Mg deficient.
This is a pretty good indicator but cumbersome to do.

Once it was thought that testing the Red Blood cells for their Mg levels would give a better indication of intercellular Mg but unfortunately it is now known that the Mg levels in RBC can vary considerably depending on the age of the cells. However tests on White Blood cells (leukocytes) appear to be much more accurate.

Other websites dealing with magnesium you can visit:-
The Magnesium Web Site
The International Medical Veritas Association (IMVA)

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