Magnesium (3)

Intake and deficiency of Magnesium

Magnesium is second only to potassium among those who failed to meet the intake targets in a UK survey. More women than men failed to reach their target and the younger age groups were worst affected.
The low average intake of Magnesium is often reflected in the low proportion of magnesium from cereals. In a well-balanced diet, the wholegrain food group should provide at least half the magnesium intake. Magnesium intake would be improved several fold by simply replacing refined cereal products with wholegrain equivalents.

Other factors can lower magnesium status, including malabsorption, kidney problems, endocrine disorders and alcoholism.

Magnesium absorption can also be jeopardised when calcium intake is very high: for maximal absorption of both minerals, the Ca:Mg ratio in the diet should be 2:1. Ideally, therefore, magnesium should be included in calcium supplements for bone health. Interesting though is that from the Carbohydrate food group ("sugary products”), which include jams, confectionery and soft drinks; beer (!) is the main contributor of magnesium in this category because yeast contains high amounts of magnesium.

The effects of mild magnesium deficiency include a variety of signs and symptoms affecting the neurological and neuromuscular systems. These include muscle cramps or twitches, palpitations and restless legs. More seriously, magnesium deficiency may cause or exacerbate cardiovascular disease (heart disease), especially arrhythmias (irregular heartbeats).

The assessment of magnesium status proves to be problematic. Although commonly used, serum magnesium concentration is inadequate. Red blood cell magnesium, although a better measure as it reflects the intracellular nature of the mineral, is still not universally accepted. The best method is a classic research technique: recovery of magnesium from 24- hour urinary magnesium excretion following a known load of magnesium administered parenterally, compared with a baseline 24-hour urinary magnesium. In other words, give the subject a known amount of magnesium and collect urine over a 24 hour period. Compare the excretion of magnesium with the excretion over a similar period without taking the extra amount of magnesium. This should indicate how well magnesium is absorbed, utilised and excreted.

Tough tests to do. The best to do is to ensure adequate intake through the natural dietary process. Eat healthy.
More on that in the next (nr 4) session on Magic Magnesium . . . .