What is a Toxic Magnesium Dose?

Can I get too much magnesium?

Is it possible to overdose on magnesium supplements? What are the signs to look for? What is the best way to cater for magnesium needs?

It's almost impossible for you to get a toxic magnesium dose or overdose, unless magnesium is given at high dose intravenously, where there is no magnesium deficiency or the person has kidney problems and can’t excrete excess salts.   “Magnesium is relatively safe to apply because toxicity may not occur before oral intake of 30 gram magnesium sulfate (MgSO⁴).” (Herroeder et al., 2011)   As Epsom Salts (magnesium sulfate) contains about 9.7% elemental magnesium, 30 gram would equate to approx. 2,900mg elemental magnesium.

Even a few hundred milligrams taken orally can have you sitting on the toilet with very liquid stool, and this amount is far from toxic.  So fear not!  Magnesium is one of the safest food supplements.

When it comes to upper limit oral doses set by medical authorities, they are calculated according to the diarrhea effect on an average adult and bear no relationship to how much magnesium supplementation a person may actually need for optimal nutrition. 

“The European Scientific Committee on Food (SCF) analyzed data from studies on magnesium supplementation with doses ranging from 180 to 1,095mg elemental magnesium per day. The ESCF concluded that mild diarrhea was an established effect in studies of adult patients at oral doses of around 360-365mg elemental magnesium per day. No laxative effects were reported in adults, including during pregnancy and lactation in women, at doses of up to 250mg elemental magnesium per day, or in children aged 4-12 years at up to 245mg elemental magnesium per day.” (tga.gov.au)

In fact, the real danger is not in getting a toxic magnesium dose, but in not getting enough magnesium. It is estimated that the majority of people in modern societies are to some extent magnesium deficient due to declining magnesium in the food supply, combined with excessive stress levels. Even if you think you are consuming a fresh healthy food diet, you may not be getting enough magnesium from the food alone if your stress levels are high or chronic.  That means any kind of stress, including background noise stress, sleep deprivation and shift work, hard physical work and excessive exercise, chemical or drug exposures, or psychological stresses.

Researchers have also found a large range of potential magnesium needs among individuals, and this can also fluctuate from day to day, depending on stress levels.  We’re all different.  One size doesn’t fit all! The more physical or psychological stress is experienced, the more it depletes magnesium levels, as magnesium is lost excessively under stress. (Seelig, 1994)

What if you need a higher magnesium dose than what tablets or food can deliver to cells?

If you have high end needs, and diet doesn’t supply enough magnesium dose, what are your options?  If you take enough oral magnesium supplement to give you diarrhea most of the magnesium is expelled by the digestive system before it has a chance to make it through the bowel wall to get to muscles, joints and organs. That’s okay if the purpose of taking it is for the laxative effect, but this is short changing you on the magnesium you may need for tissue cells.

Studies have shown that only a dilute amount of dissolved magnesium, such as what would naturally occur in spring waters and foods, can efficiently and optimally cross the endothelial lining of the bowel to the interior of the body, where magnesium is mostly used and stored in the tissue cells of muscles, organs and bone. As scientists titrated the magnesium dose in water upwards, more and more magnesium was expelled by the digestive system.  There was a curvilinear response to magnesium absorption and bioavailability, showing the higher the concentration, the less passed through the bowel wall, and the more was wasted. It’s also better to consume magnesium in smaller amounts more frequently during the day.

“The fractional absorption rate is high at low magnesium load and decreases exponentially with increasing carrier amounts. Several authors have outlined that higher bioavailability is observed when a given amount of magnesium is distributed over a day rather than being consumed in a single bolus.” (Verhas, n.d.)

How can we get more of a magnesium dose to fill the vacuum – and of course without causing a bowel purge?!  Well, for thousands of years different cultures, such as the Japanese, Persians and Europeans, have been soaking in rich mineral salt baths to absorb higher amounts of magnesium and other soluble trace elements through the skin. This process of periodic balneotherapy has been used to alleviate symptoms of stress, arthritis, aches and pains.  It was long considered a detox and rejuvenating therapy, and is still a popular tradition in modern times.

Your skin is the largest organ of the body, its outermost barrier being constructed of collagen scaffolding, and having pores and channels that open and close depending on what the body is doing.  If you need to perspire for instance, channels connected to the lymph system open and release water, waste products and electrolyte minerals.  The salty taste in your sweat indicates the presence of these excretions. 

However, this system can also work in reverse, with the absorption of electrolytes such as magnesium from the soak waters.  When you soak in a hot bath using magnesium chloride or magnesium sulfate (Epsom salt), the outside layer of barrier fats slightly melt and release some stored dust and grime in the process.  It also opens the skin channels more to allow a better absorption of dissolved magnesium ions for a potent magnesium dose.

The main difference in effect of the Epsom salts compared to magnesium chloride is that Epsom salt has 9.7% elemental magnesium, whereas magnesium chloride salt has 15 to 16%. Epsom salt, having the sulfate component, is also skin drying and can cause irritation in sensitive skin, whereas magnesium chloride is gentler and more hydrating for skin.

The skin in this way acts like a reservoir, which fills up with moisture and electrolytes.  When this reservoir becomes saturated, magnesium absorption subsides, so the body does not get too much of a magnesium dose.  If you soak too long your skin can also get shriveled!  If you have a magnesium bath with a cup of magnesium chloride flakes, or a magnesium foot-soak with a tablespoon of flakes, your optimal absorption happens within the first 20-30 minutes. This is one of the best and gentlest ways to relax and unwind. It helps the body release tension, to detox, and also promotes a better and deeper sleep. And anyone can tell you how restorative a deep and restful sleep is.

We need magnesium every day because the body uses so much of it to re-balance from stress and pressure. Calcium contracts; magnesium relaxes. Every second, every time your heart beats, 24/7, your body is using up magnesium resources which need to be replenished.  Magnesium is the master mineral with 350 direct functions and over 1,000 indirect enzymatic functions in the body.  It sparks up our electrical supply for detoxification, making proteins such as hormones, enzymes, collagen and elastin, organ function, bone and muscle building, and controlling how calcium behaves in the body.  Massive tasks!  And a lot can therefore go wrong if we don’t get enough magnesium. 

Some people can need 1,000mg or more of magnesium per day to cope with and help recover from stresses, injury, sleep deprivation, arthritis, rheumatism, medications, drug or alcohol abuse, athletic performance or pregnancy.  Some can also lose excessive amounts of minerals that would normally be recycled. This loss by kidneys increases with chronic stress.  I call it ‘leaky kidneys’. This affects their ability to properly balance pH, leading to acidosis, which leads to increased inflammation and degenerative disease. We literally get dissolved by the free radicals of the acidity. These people need to put a lot more magnesium in (as well as other antioxidants and alkalizers), to keep up with the loss from the ‘holes in their bucket’ (leaky kidney).

If you don’t supply your body the daily magnesium it needs for energy metabolism, detoxification, building new cells etc., after a while you use up your stored resources and then the body can move into a ‘burn-out’ phase, which resembles Post Traumatic Stress Disorder (PTSD) and a heightened inflammatory response.  It can lead to osteoporosis, diabetes and heart disease – basically all the degenerative diseases.  This is why researchers have called magnesium ‘The Antiaging Mineral’.  I have called it ‘The Master Mineral’ because we need it to do more jobs than any other mineral, and it regulates homeostasis and balance in the body.  It is also our nurturing and recovery mineral and could even be called ‘The Mother Mineral’.

Daily magnesium soaks may be very impractical for many people on a daily basis, so another alternative is to apply magnesium cream moisturizer, lotion or oil.  Magnesium oil is water-based and may on its own not be enough to penetrate sufficiently. This high concentration of magnesium salts can leave the skin irritated and feeling prickly – unless enough fats are available.  When the magnesium chloride is infused into plant fats, because the skin is lipophilic (loves fats), it absorbs magnesium more readily.  The combination of plant fats and magnesium chloride is great for skin barrier protection, as well as improving smoothness and complexion.  Therefore, you can use this form of magnesium not only for muscle relaxation, but also for skin care and sun-care too.

When your skin absorbs magnesium cream or lotion, the magnesium ions and lipids sit inside the skin layer like food in a container, hydrating and plumping up skin cells for an extra antiaging beauty bonus.  It’s like a smorgasbord of nutrients available for several hours after application, so the body is free to take up what it needs in its own time, and without need to digest anything, as the dissolved magnesium chloride is already in the right form for cellular uptake of the magnesium dose they need.  Magnesium ions have been shown in studies to pass through the skin not only via the skin pores, but also transcellularly, that is, tissue cell to tissue cell. This happens in a self-regulated way, dependent on magnesium status. (N. C. Chandrasekaran et al., 2014) (N. Chandrasekaran, 2016) (Sang-ngern et al., 2012)

You can use as much transdermal magnesium as you like without fear of excessive magnesium dose, because the amount able to be absorbed is limited by the fats and carrying capacity of the skin layer.  In other words, the epidermis of the skin would fill up faster with the fats, becoming saturated so that for a while it can’t take up anymore.  In this way a toxic quantity of magnesium (2,900mg in one dose) cannot enter the inner domain, as it would be able to via intravenous injection.  You couldn’t even get this much into you orally because you would be pooping it out at 360mg doses.

Two teaspoons of magnesium cream (enough to cover the whole body) delivers approximately 300mg magnesium, which remains available for transdermal uptake for several hours.  If your body is very hungry for magnesium it will go in faster; and if not so hungry, a bit slower.  Spreading out your topical magnesium applications throughout the day, as well as regularly drinking magnesium water (spring water concentration), ensures you get optimal uptake.

You could also apply the more concentrated Magnesium Charge Lotion and/or Magnesium Oil Spritz for massage into more stubborn areas of the body. Try different combinations until you learn about what you need, what feels good to you and how you like to use it.

Think of magnesium as a cell defender and regulator, the body chooses its own magnesium dose from what becomes available, and we need a lot in our cellular bank accounts to deal with high-end needs as a result of stress, so that we can recover stronger.

For a guide as to how much magnesium is potentially in each product use, please see FAQ page and refer to this chart…

By Sandy Sanderson © 2020  

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