The many roles of Magnesium

Woman sitting on beach – The many roles of magnesium article

The many roles of magnesium

We should never underestimate the importance of magnesium, and the roles it plays in our general wellbeing. It is one of the more well-known and most available minerals available in supplement form, but there are still widespread deficiencies across the population, particularly among older adults.

Although there a no comprehensive studies monitoring the New Zealand population and its magnesium status, we know that our soils are low in magnesium. In the USA it’s estimated that two-thirds of all adults, and up to 90% of the elderly are not getting their Recommended Dietary Intake (RDI) of this essential mineral.

There are a number of reasons for this. These include the depletion of minerals in the soils through intensive farming, the prevalence of processed foods which further strip away the mineral content, inadequate diet and lack of exercise, and increases in stress and anxiety. The increased use of antibiotics, antacids and prescription medication can also have a detrimental effect in terms of magnesium absorption.

✔️ Calm nerves and anxiety

✔️ Reduces inflammation

✔️ Helps regulate blood sugar levels

✔️ Supports deep sleep patterns

✔️ Relieves muscle aches

✔️ Heart regulation

Magnesium is required for many biological functions within the body, including more than 300 enzyme reactions. Below are some of the benefits of magnesium and the crucial roles it plays in the health of our heart, our muscles and our brain. There are reasons why we need more magnesium when pregnant or when placing significant demands on our bodies in terms of physcial activity. It also explains how we can get more magnesium into our diet through the foods we eat and what we should consider when looking to supplement.

Magnesium for your heart

Adequate levels of magnesium are required for maintaining the function of the nervous system and neuromuscular transmission and activity. It helps with heart muscle contraction-relaxation and regulating the heartbeat. Along with other macro minerals such as calcium, sodium and potassium, magnesium affects the muscle tone in the blood vessels, which enables optimal blood pressure control, with a decreased risk of erratic heartbeat and coronary artery disease.

Man looking out at ocean
Populations with high intakes of magnesium have a much lower rate of cardiovascular disease.

Our nerves depend on magnesium to help keep our arteries relaxed, and free from inflammation, which is the main cause of cardiovascular disease. This allows for good circulation, healthy arteries, and to ensure sufficient blood flow to all parts of the body, including our brain.

The World Health Organisation (WHO) estimates that one in three deaths are attributed to cardiovascular disease. Populations with high intakes of magnesium have a much lower rate of cardiovascular disease, diabetes, arrhythmia and hypertension compared to those with insufficient levels. Magnesium supplementation programmes have shown to have a significantly postive effect on the treatment of patients with cardiovascular disease, and researchers have advocated for a higher RDI of this essential nutrient for many years.   

Magnesium for muscles and sleep

Magnesium can relax the muscles, our nerves and the mind. It also helps to avoid muscle cramps, headaches and can lessen the effects of stress, leading to a better quality of sleep. 

People with low magnesium status can be tense and irritable, and suffer from cold hands and feet due to poor circulation. They can find it hard to calm the mind and relax, and get a proper night’s sleep.

Woman sleeping in a bed. Magnesium can assist with alleviating muscle cramps at night.
Magnesium is best taken at night as it contributes to physical and mental relaxation.

The best I’ve had. I feel the difference almost immediately. No digestive problems with this. Helps me sleep and relax in general.”


Common symptoms of magnesium deficiency include muscle cramps, especially at night, as well as fatigue, insomnia, high blood pressure and heart disturbances.

Magnesium is best taken at night as it contributes to physical and mental relaxation, lessens the effects of stress, and when paired with a consistent night-time routine it can greatly assist with getting a restful night’s sleep.

Magnesium for your brain

Along with metabolic health and muscular function, magnesium is critical for brain health. It can help support cognitive function, especially among older adults who are at greater risk of deficiency.  

It is also essential for both short and long term memory, enables concentration and learning, and helps with mood, behaviour and healthy aging.

Our brains require an enormous amount of energy – up to 20 percent of all the body’s energy. This requires a constant supply of magnesium, and the trillions of neural networks and synapses within the brain need magnesium to process information. 

Magnesium is essential for brain function.
Magnesium is essential for brain function and acts on receptors which help brain development.

Magnesium has been shown to regulate the receptors in the brain associated with learning, memory, mood regulation. Abnormal NMDA receptor activity has been present in patients presenting with Alzheimer’s, Parkinson’s disease as well as depression and anxiety.

“Brilliant product. Sleeping much better compared to other magnesium products that I’ve tried. And my few muscle cramps have disappeared. Though the taste isn’t great, I choose to swallow it straight as the taste soon disappears, so it’s no problem.”


Low magnesium status has been linked to anxiety, fibromyalgia, age-related memory loss and depression. In addition, the various medications used to treat depression can further contribute to decreased magnesium levels.

In 2017, to assess the effects of magnesium supplementation, an open-label, randomized, cross-over trial was done with 126 adults who had been diagnosed with mild-to-moderate symptoms of depression. (6) Supplementation was undertaken with 248mg of magnesium chloride per day for 6 weeks, compared to 6 weeks of no supplementation. It led to a clinically significant improvement in mood and anxiety scores, and positive effects were observed within two weeks. The magnesium chloride was also well tolerated, and 61% of participants reported they would use magnesium in the future.

In another study of more than 1,000 older individuals who were followed for 17 years, those with higher intakes of electrolytes such as calcium, potassium and magnesium had a lower risk of developing dementia. (7)

Magnesium for performance

As magnesium helps with regulating the heart and muscle contraction and movements, it is crucial for physical performance, and should be a part of any sports nutrition progamme. 

Woman running on New Zealand beach. Iron for energy.
Supplementation can avoid muscle cramping and even migraines during exercise.

Along with potassium, sodium, chloride and calcium, magnesium is an electrolyte, and is able to hold an electrical charge to supply these macro minerals to our cells accordingly.

Magnesium is depleted in the body through excessive sweating, and supplementation can be required to avoid muscle cramping and even migraines during exercise. As good quality sleep is so important to performance, maintaining sufficient levels of magnesium in the cells is necessary for athletes to enable recovery of both mind and body.

Athlete stretching on running track. About 60% of the magnesium in your body is found in bone, with the other 40% found in muscles.
Magnesium is the fourth most abundant mineral in the human body. About 60% of the magnesium in your body is found in bone, with the other 40% found in muscles, soft tissues and fluids. 

Magnesium when pregnant or breastfeeding

When pregnant or breastfeeding, your body requires even more vitamins and minerals, especially iodine and selenium, and also magnesium, all of which are in short supply in the New Zealand soils. Magnesium plays a big part in the baby’s development and growth, and the health of the mother during this important time.

Higher amounts of magnesium have been shown to relieve pre-eclampsia and hypertension in women during the latter stages of pregnancy, and pregnancy-induced leg cramps.

The RDI for Magnesium in women is 310mg per day, but increases to 360mg when pregnant or breastfeeding.

How to get more magnesium into your diet

Through eating a balanced, whole-food diet, you can obtain good levels of magnesium from food sources. The less processed foods you eat the better. For example, approximately 80% of magnesium is lost when wheat is refined into white flour, and all magnesium is lost in the refining of white sugar.

Green leafy vegetables and raw, unsalted nuts (almonds, walnuts) and seeds (pumpkin/sunflower) sweetcorn, dates, beans and bananas are the best plant-based sources of magnesium. Other foods such as wheat bran, quinoa, dark chocolate and seafood such as shrimps and pipis contain good levels of the mineral.

How to get more magnesium into your diet with these foods. Green leafy vegetables, pumpkin seeds, sweetcorn, bananas, dark chocolate and almonds are all good sources of magnesium.
Green leafy vegetables, pumpkin seeds, sweetcorn, bananas, dark chocolate and almonds are all good sources of magnesium.

Gut health plays a significant part in the absorption of minerals and vitamins from our food, and so too with magnesium. If you experience digestive issues, your body may not be able to utilise the magnesium found in your foods.

“Couldn’t be without it. Have used this for years now. Great for headaches and deep sleep. Take it in a small amount of water just before bed and I always sleep peacefully.”


Stress, excessive alcohol intake, excessive sweating, the use of prescription drugs, and advancing age are all factors that can lead to magnesium deficiency. If you’re unable to access sufficient levels from your diet, supplementation may be an option. Magnesium supplements can be found in many forms – capsules, tablets, epsom salts, and liquid mineral formulas.  

Supplementing with magnesium

When considering supplementation, you should look for highly bioavailable options. These inlude organic forms such as magnesium citrate, or ionic liquid mineral supplements, which are more easily absorbed and tolerated by the body.

To generate magnesium ions, the compound must dissolve in water, but common supplements such as magnesium oxide do not dissolve and therefore cannot deliver magnesium ions into the bloodstream, and then into your cells and bone where it needs it most. 

The RDI for magnesium is 310mg for females, increasing to 360mg when pregnant or breastfeeding. The RDI for adult males is 420mg.

When should I take it?
While it’s best taken at night as it contributes to physical and mental relaxation, it can be taken at any time.

Individuals with kidney disease, severe heart disease or on prescription medication should consult their health practitioner before taking a magnesium supplement.  


Most of us could benefit from topping up our magnesium stores, and the health benefits it provides. Whether we’re taking it for our heart, our brain, to get more energy or improve the quality of our sleep, magnesium is responsible for more than 300 enzymatic reactions in the body, so there’s hardly any part of the body that doesn’t benefit.

The information in this article is not intended as a medical prescription for any disease or illness. Nothing stated here should be considered medical advice. Use as directed. If symptoms persist, consult your healthcare professional. 

Are you getting enough Iodine?

Woman holding mug and looking out to sea. Are you getting enough iodine?

Are you getting enough iodine?

When you hear the word iodine, you may think of the tablets used to disinfect water on camping trips or the yellow liquid used for disinfecting cuts and grazes when we were younger. Or you may just remember it from the periodic table in chemistry class.

Iodine is one of the most important life-sustaining elements. For more than 100 years, it has been known as the element that is necessary for thyroid hormone production. However, it is so much more than that.

Iodine is found in each and every one of the trillions of cells in the body, and responsible for the production of all the other hormones in the body.

It is a powerful antibiotic, and has potent antibacterial, antiviral properties.

It has strong anti-inflammatory effects by neutralising free radicals and is necessary for proper immune system function. Working together with other minerals like Selenium, it has many therapeutic benefits for a range of modern illnesses and diseases.

It is estimated by the World Health Organisation (WHO) that more than half of the world’s population live in an area of iodine deficiency, and that this has risen 400% in the last few decades due to soil depletion and an increase in environmental contaminants that have replaced it.

Our body does not make iodine, so we need to access it from the foods we eat. But if the nutrients are not in the soil to begin with, it cannot be in the food we eat, and this can lead to common deficiencies.

Iodine deficiency in New Zealand

Soil in coastal areas are naturally iodine-rich, as are the dairy products produced by the cows that graze there. Fresh produce such as fruits and vegetables that are grown in coastal areas are also rich in iodine.

Despite being a coastal nation, New Zealand soils are low in iodine, and this is reflected in our locally grown produce.

This can be due to intensive farming, lack of crop rotation and the use of fertilisers. Coupled with changes to our diet, the reduced use of iodised salt in the household, the prevalence of processed foods, many New Zealanders are now lacking important nutrients such as iodine that are key to good health.

The WHO’s research has suggested deficiencies in both Australia and New Zealand are re-emerging, when they were previously thought to be iodine sufficient.

This research suggests that we may be consuming less than 60% of what is recommended. While we all need iodine, it is especially important for women who are trying to fall pregnant, are currently pregnant or who are breastfeeding, as the body demands more during this time due to increased thyroid hormone production, and the requirements of the developing baby.

Woman smiling and leaning on fence in countryside.
Research suggests that we may be consuming less than 60% of what is recommended.

Properly evaluating and treating iodine deficiency will help people support thyroid health and immune system function, increase their energy levels, and help improve general health and wellbeing. This can be achieved by some simple changes to their diet or daily supplementation in consultation with their health practitioner. It can be as little as a couple of drops of potassium iodide in a glass of water each day to get you feeling better, and help you avoid some of the common but serious health problems we are seeing today in New Zealand and around the world.

The best results are seen with a holistic approach, and increasing the intake of important vitamins, minerals and electrolytes through a wholefood diet.

The hungry thyroid

The thyroid is often referred to as a ‘hungry’ part of the body, in reference to its high nutritional demands.

This butterfly-shaped endocrine gland surrounds the windpipe and is important for metabolism, regulating digestion and your heart rate. It facilitates energy production and mental agility. The thyroid also helps with fat burning too, by determining how quickly and efficiently kilojoules are burned up, and it assists in the breakdown of proteins. Thyroid function also assists the suppleness and strength of our hair, skin and nails.

Iodine is an essential ingredient in all thyroid hormones, including T4 (thyroxine) and T3 (triiodothyronine). It is important to maintain sufficient amounts of iodine, and they are required to be synthesised in adequate amounts. In a low thyroid state, known as hypothyroidism, the thyroid gland can’t make enough thyroid hormone to keep the body running normally. The metabolic state is therefore reduced which can lead to weight gain.

When the thyroid gland is releasing excess amounts of thyroid hormone, it is known as hyperthyroidism, which is an overactive or elevated metabolic state which can result in fatigue, irregular heartbeat, unexplained weight loss and brain fog.

When you have an adequate intake of iodine, your body contains 20-50g, and 75% of that amount is stored in the thyroid. However large amounts are also stored in other parts of the body, including the salivary glands, the breasts, ovaries, and the brain. In the brain it concentrates in the substantia nigra, the part of the brain that is associated with Parkinson’s disease.

One of the first signs of deficiency is an enlarged thyroid gland.

The lack of iodine causes the gland to expand in an attempt to extract as much iodine in the bloodstream as possible. If your iodine intake is low, this will be reflected in low levels of thyroid hormone. You may then experience fatigue, dry skin, constipation, systemic inflammation, a hoarse voice, delayed reflexes and some cognitive impairment.

It is best to consult your doctor or health professional should you identify any of these symptoms. Anybody taking thyroid medication should always discuss their condition with a health professional before taking supplementary iodine.

The role of selenium

Selenium, another important mineral and antioxidant, plays a significant role in regulating thyroid function and iodine metabolism. The thyroid contains more selenium by weight than any other organ in the body.

Selenium is a required component for the production of the enzyme glutathione peroxidase, which protects the body from damage with antioxidant capabilities.

Without this enzyme, the thyroid gland is susceptible to damage from oxidants, there would be no activation of thyroid hormone without selenium.

Pregnant woman lying on bed. Pregnant and breastfeeding women require more iodine.
Pregnant and breastfeeding women require more iodine.

The need for iodine before pregnancy

The consequences of iodine deficiency are most serious for women who are trying to fall pregnant, who are currently pregnant or are breastfeeding.

Thyroid hormones balance the function and development of the body’s major organs and influence the progress of the developing baby.

Research has shown that a lack of iodine can cause fetal and neonatal mental disabilities and growth problems, along with speech and hearing issues. Cognitive function and neurological development can be impaired when iodine levels are low.

Pregnant and breastfeeding women also require more iodine due to increased thyroid hormone production.

It is recommended that women take iodine supplements from the point of planned pregnancy and through the full duration of pregnancy as well as breastfeeding. Avoid kelp or seaweed supplements as they may be contaminated with heavy metals such as mercury. Multi-vitamin, multi-mineral and pre-natal supplements may or may not contain enough iodine, so it’s best to check.

Women with pre-existing thyroid conditions should always check with their health professional before taking a supplement.

How do I know if I’m deficient?

Under most states of iodine sufficiency, approximately 90% of dietary iodine eventually is excreted in the urine, with exception being the lactating female due to iodine excretion in the breast milk. Because of this, urine is the best biological fluid to use for assessment of deficiency.

If you are concerned there may be deficiency, you could undertake an iodine-loading test, otherwise known as a urinary iodine concentration (UIC) where you take a prescribed dose of iodine, then collect 24 hours of urine to undergo analysis with a health professional.

The principle of this test is that if you’re iodine sufficient, most of the dose will be excreted, and if there is a deficiency present, it will be instead be absorbed by the body.

Can I get enough iodine from salt?

Iodised table salt was implemented in many regions and countries around the world when iodine deficiency was recognised. In New Zealand in the 1920’s, the government allowed manufacturers to voluntarily add iodine to table salt. This was mainly to safeguard against thyroid enlargement (goitre) and the severe mental retardation of cretinism, although the incidence of these conditions was very rare in New Zealand.

Closeup image of unrefined, unprocessed sea salt. A better option than table salt.
Unrefined, unprocessed sea salt is a better option than table salt.

In recent decades we have seen people consume less salt due to health concerns, while some avoid salt entirely. Salt used in processed foods is often non-iodised to save on costs, so is not a source of iodine despite the sodium content.

In recent times we are seeing a prevalence of sea salt, or kosher salt, promoted as a healthier alternative. However, sea salt is a poor source of iodine, and we should look for unrefined, unprocessed sea salt, with some products now enriched with New Zealand sea kelp. The iodine in salt is not very bioavailable in our bodies, it is better absorbed through liquid and food sources. 

Other sources of dietary iodine

It can be difficult to identify sources and the quantity of iodine in most foods. However, it is naturally present in seawater, so therefore seafood is a good source, especially seaweed, shellfish and saltwater fish. It’s also naturally present in soil, and found in eggs and dairy, including yoghurt, cow’s milk, ice cream and cheese.

If you don’t have access to shellfish or other seafood, or if the soil is deficient due to intensive farming, you’ll need to access it from other sources.  

Iodine levels in milk can vary according to the soils in which the animals have grazed and factors such as the groundwater used in irrigation, fertilisers used and the feed for the livestock. Interestingly, organic milk is estimated to contain roughly 30-40% less iodine than conventional milk, owing to alternative processing methods.

It is difficult for most people to obtain adequate iodine by eating foods that are natural sources of iodine.

That said, in 2009, Iodine fortification of bread became mandatory with the exception of organic bread, non-yeast-leavened bread and bread mixes. When salt was iodised in the 20th century, this significantly improved the iodine levels within the New Zealand population, but recently deficiencies have again become apparent, hence the need for the fortification of foods.

Iodine dosage guidelines

There is no single dose of iodine that is effective for everyone. The best approach is working with a health professional that is knowledgeable about iodine.

If you eat seafood and other iodine-rich foods, use iodised salt, take a multi-vitamin or mineral supplement, you may be able to obtain adequate levels.

Recommended daily allowances range from 100-250mcg a day, with the exception of pregnant or breastfeeding women, who may require more than 300mcg per day due to increased hormone production in early pregnancy, increased urinary iodine excretion, and the transfer of iodine to the fetus or the nursing infant when feeding.

Some leading iodine experts suggest significantly larger daily doses, even up to 12mg. In Japan, the average daily intake is 12-13 milligrams due to increased consumption of seaweed and other seafood.

Iodine Liquid Mineral: Just 2 drops a day = 255mcg of Potassium Iodide


Iodine is one the most basic elements of all life on earth, it is present in the ocean, marine life and in every one of the trillions of cells in our body. The role it plays in our everyday wellbeing cannot be overstated. As our bodies can’t produce iodine, there are simple steps we can take to make sure we can rebalance and replenish our mineral levels, and avoid deficiencies.

Brownstein, MD. D. Iodine. Why You Need It And Why You Can’t Live Without It. 2014
Reader’s Digest. The Healing Power of Vitamins, Minerals & Herbs. 2000
Schauss, Alexander G. Minerals, Trace Elements, & Human Health. Life Sciences Press. 1995
Kohrle J. The Trace Element Selenium and The Thyroid Gland. Biochimie. 1999
Smallridge RC, Ladenson PW. Hypothyroidism In Pregnancy: Consequences To Neonatal Health. J Clin Endocrinol Metab. 2001
Iodine. Ministry of Health Manatū Hauora Website.
Editors: de Benoist, Bruno. Andersson, Maria. Iodine status Worldwide. WHO Global Database on Iodine Deficiency. World Health Organisation, Geneva. 2004
Ministry of Health Manatū & Australian National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes. 2006, updated 2017.

The information in this article is not intended as a medical prescription for any disease or illness. Nothing stated here should be considered medical advice. Use as directed. If symptoms persist, consult your healthcare professional.