Magnesium has long been known as a treatment for high blood pressure in pregnancy, and as an anticonvulsant. Its effects on the heart were first described as long ago as 1935. However, magnesium could be considered a forgotten mineral until recently, when more reports of its importance have appeared in the medical literature.
WHAT IT DOES
Magnesium is the second most abundant mineral inside cells after potassium, and its distribution across cell membranes is closely link with calcium and phosphorus metabolism. The average human adult has 20-30b of magnesium, seventy percent of which is contained in teeth and bones; the remainder – the physiologically important component – is found mainly in the cells. The average daily intake of a healthy adult should be 400-800mg, but requirements can increase in certain circumstances, such as with high – protein, high-calcium, high-phosphorus, or high-vitamin D intakes.
A diet high in refined and processed is often deficient in magnesium, and this is made more significant if bran is added to such a diet because it binds what little magnesium is present, so rendering it less easily absorbed.
Magnesium is essential for many metabolic processes, especially the cellular ‘pumps’ which maintain the correct distribution of sodium, potassium and calcium across cell membranes. Magnesium deficiency is associated with muscle cramps, or in extreme cases, tetany – continuous cramps, especially of the hands and feet.
Because magnesium is involved in so many enzyme systems a deficiency has widespread metabolic consequences.
Sources rich in magnesium include nuts, winkles, shrimps, soya beans, whole grains, and green, leafy vegetables (magnesium is a component of chlorophyll, so the greener the vegetables, the more magnesium there is). Tap-Water in hard water areas is also an important sources of dietary magnesium.
DEFICIENCY SYMPTOMS AND SIGNS
The symptoms of magnesium deficiency centre around the neuro-psychiatric end of the spectrum of disorders and include:
- Loss of appetite
- Weakness and tiredness
- Numbness and tingling
- Confusion and disorientation
- Learning disability and memory impairment
- Convulsions, epilepsy
- Muscle cramps, grimaces, jerks, tremors
- Tremor and jerks of the tongue
- Eyes flick uncontrollably
- Muscular incoordintation
- Heartrhythm problems
- Susceptibility to toxic effects of digoxin
- Difficulty in swallowing
- Abnormal ECG
- Premenstrual symptoms
Magnesium status should be assessed in anyone with these complaints. Because magnesium is needed for vitamin B1 metabolism, many of the symptoms can be associated with a vitamin B1, or B6 deficiency and these should be looked for in anyone complaining of these symptoms.
CONDITIONS IN WHICH MAGNESIUM SUPPLEMENTATION MAY BE USEFUL
Until recently, doctors measured serum magnesium (the amount in the blood), which turns out to be an extremely poor indicator of magnesium status. As a result doctors’ awareness of magnesium deficiency is probably of significance. A few of the conditions in which magnesium is of proven value are:
Osteoporosis is a condition in which calcium is removed from the bones, and the result is brittle bones that fracture easily. It is common in old people and especially in post-menopausal women. Two hormones, calcitonion (CT) and parathyroid hormone (PTH), regulate the skeletal turnover of calcium. Magnesium suppresses PTH and stimulates CT secretion, thus favouring the deposition of calcium in the bones and the removal of calcium from soft tissues. Furthermore, magnesium enhances calcium absorption from food and its retention in the body, whereas increasing calcium intake suppresses magnesium absorption. So there are sound theoretical grounds for using magnesium supplements in preventing or treating osteoporosis.
When deposition of calcium in soft tissue is increased, by a deficiency of magnesium, muscle and joint aches and pains could result. In our clinical experience, magnesium supplementation can be beneficial, in addition to other therapeutic interventions.
These include nervousness, anxiety, insomnia, childhood hyperactivity, depression, anorexia, apathy, weakness and tiredness. Many of these are associated with vitamin B1 deficiency, and magnesium is essential for the efficient utilization of vitamin B1 as well as B6. Magnesium deficiency is also associated with increased lactate levels which in turn have been linked to a wide range of symptoms. (Vitamin B1 deficiency can result in increased lactate levels.) So, clearly, magnesium deficiency must be considered as possible cause of, or contributing factor to, a whole range of psychiatric symptoms.
Magnesium supplementation, along with vitamin B6, can be of real value in the management of premenstrual syndrome (PMS). Vitamin B6 alone increases red-cell magnesium levels, which are often low in women suffering from PMS, and magnesium supplementation along with several other nutrients has been shown to increase premenstrual progesterone levels. Also, women in the premenstrual phase are more subject to hypoglycaemia and it has been found that hypoglycaemia is more marked in magnesium deficiency. Magnesium reduces the extent of reactive hypoglycaemia and its symptoms.
Spasm of the coronary arteries and increased excitability of the heart muscle, due to magnesium deficiency, can produce abnormal cardiac rhythms and even cause sudden death from heart attack. People who die from heart attacks have been found to have lower magnesium in their heart muscle than those dying from car-accident injuries.
Magnesium deficiency caused by water tablets
Short-term, vigorous diuretic treatment, or moderate-dosage, long-term treatment can give rise to significant magnesium shortages. This depletion is also often compounded by hospital diets, which are surprisingly low in magnesium, a soft water supply, and, in some people, a high alcohol intake. Research from Dublin has found that the commonest symptoms include depression, muscle weakness, and a disorder of heart rhythm which doesn’t respond to diogxin treatment. Psychiatric symptoms may also appear as a result of low blood sugar (hypoglycaemia) due to magnesium deficiency. It seems that the elderly are most at risk, especially those who have excessive alcohol intake, a diet low in magnesium, or a soft water supply.
Magnesium deficiency has been recognized as a possible causative factor in hypertension.
Magnesium is one of the elements that is depleted in chronic alcoholism, probably as a result of decreased intake, the poor absorption of what is eating, and poor re-absorption of magnesium by the kidneys. Alcohol acts as a diuretic and promotes the loss of both potassium and magnesium in the increased urine output. It has been found that levels magnesium in sweat and blood can be low in alcoholics and that this can be partially corrected after three weeks of abstinence.
Diabetes mellitus causes substantial magnesium loss partly because of the large volumes of urine passed. This loss can further be contributed to by the kidney disease so commonly seen as a complication of diabetes.
Epilepsy and convulsions
There is a definite correlation between magnesium deficiency and the incidence of convulsions. We believe that epileptics should have their magnesium status assessed.
It seems from our professional experience that many hyperactive children have poor magnesium status and that their symptoms may very well be due, at least in part, to an existing magnesium deficiency. Hyperactive children and learning-disabled children often drink a great deal of cow’s milk. Whilst many of their symptoms may well be attributable to cow’s milk intolerance, it is quite feasible that too much cows’ milk can predispose to magnesium deficiency as a result of its extremely low magnesium:phosphorus ratio.
The cheapest for of magnesium supplement is magnesium oxide, and 100 mg of magnesium oxide provides approximately 60mg of elemental magnesium. Other forms of magnesium include animo-chelated magnesium. Other forms of magnesium include animo-chealted magnesium, magnesium aspartate, or magnesium orotate. Magnesium gluconate or magnesium chloride can also be used orally, but these are less satisfactory. In the premenstrual syndrome, as much as 200-400mg daily of magnesium may be necessary; in other conditions 100-300mg in adults is usually all that is necessary. Calcium and magnesium supplementation should be in the ration of one or two parts of calcium to one of magnesium. Excessive magnesium supplementation can cause diarrhoea.