Magnesium
Along with phosphorus, magnesium
follows a close second behind calcium as
the most common mineral in the body. Around 86% of all the
magnesium is found in the bones (60%) and
muscles (26%), with the rest being distributed between the
other soft tissues (especially brain, heart, liver and kidney)
and bodily fluids.
Functions of magnesium in the body
- Important role in energy production (involved in over
300 enzyme reactions, many related to ATP)
- Involved in the synthesis of nucleic acids and proteins
(cell reproduction)
- Opposes calcium to relax muscles
- Required for cell sodium/potassium pumps to operate (cell
metabolism and nerve function)
- Stops calcium entry into blood vessel and heart
cells, reducing blood pressure by limiting spasm
and constriction
- Regulates calcium metabolism by
affecting parathyroid hormone and calcitonin, as well as
potassium and sodium.
- Necessary for hormonal activity
- Can help to prevent kidney and gall stones by its effect
on calcium levels.
- May help prevent diabetes
Magnesium
deficiency
Magnesium
deficiency can be caused by a lack of magnesium in the
diet, by an excess of calcium or by other factors which
may increase excretion or limit absorption. Magnesium
deficiency is common in the West and is often underestimated due
to the reliance on serum (blood) concentrations. As most
of
the magnesium is found in the tissues and not serum, this
will show up only severe deficiencies.
Symptoms
of magnesium deficiency
Muscle cramps
Menstrual cramps
PMS / PMT
Sugar cravings
Fatigue / tiredness
Palpitations
"Nervousness" / Anxiety
Anorexia
Anaemia
"Tics" (involuntary muscle twitches, especially on the face)
Hypoglycaemia (low blood sugar)
Childhood hyperactivity
High blood pressure
Poor circulation
Kidney / gall stones
In most cases, deficiency of magnesium is not due to insufficient
intake, but is a result of factors that increase excretion
or reduce absorption.
Some other medical conditions that may contribute to magnesium
deficiency are:
Pancreatitis
Congestive heart failure (CHF)
Digitalis toxicity
Excessive sweating
Resection of the ileum (upper end of the bowel)
Association
with other minerals and vitamins
Magnesium
is not only intimately involved in regulating levels of
calcium, it is also closely associated with potassium (especially
intracellular potassium) and phosphorus (through it's effect
on energy production and ATP - Adenosine Tri Phosphate,
which is the main cellular energy source in the body).
Factors
which reduce magnesium absorption
High calcium intake
Alcohol (excessive)
Surgery
Irritation of the digestive tract
Factors
which increase calcium excretion Use of diuretic (heart and blood pressure) drugs
Liver and kidney disease
Oral contraceptive use
Excessive exercise
Excessive tea and coffee
drinking
Many women are particularly deficient in calcium during
their menstrual period Normal
amounts of calcium in the diet
| Age |
mg/day |
| Children
(0-1 year) |
55
- 80 |
| Children
(1-10 years) |
85
- 200 |
| 11yrs+
(inc adults) |
280
- 300 |
| Lactation |
320 |
Sources
of dietary magnesium
| Source |
mg/100g |
Source |
mg/100g |
| Kelp |
760 |
Sunflower seeds |
38 |
| Wheat bran |
490 |
Barley |
37 |
| Wheat germ |
336 |
Dandelion leaves |
36 |
| Almonds |
270 |
Garlic |
36 |
| Cashews |
267 |
Fresh green peas |
35 |
| Molasses |
258 |
Sweet potato |
31 |
| Buckwheat |
229 |
Blackberries |
30 |
| Brazil Nuts |
225 |
Broccoli |
28 |
| Hazelnuts |
184 |
Cheddar cheese |
25 |
| Roasted peanuts |
180 |
Cauliflower |
24 |
| Millet |
162 |
Carrots |
23 |
| Pecans |
142 |
White fish |
23 |
| Rye |
115 |
Celery |
22 |
| Bean Curd |
111 |
Chicken |
21 |
| Dried Coconut |
90 |
Asparagus |
20 |
| Brown rice |
88 |
Beef |
18 |
| Whole-wheat bread |
76 |
Potatoes |
17 |
| Dried Apricots |
62 |
Tomatoes |
14 |
| Corn |
48 |
Oranges |
13 |
| Avocado |
45 |
Whole milk |
13 |
| Parsley |
41 |
Eggs |
12 |
Magnesium
supplements
Magnesium is best taken as part of a broad-spectrum multimineral
supplement. This will help to limit the potential negative
effect of taking too much magnesium on calcium, potassium and some other minerals. Absorption of magnesium into cells
requires the presence of Vitamin
B6.
People
requiring additional magnesium.
Those with Pancreatitis
Congestive Heart Failure
Digitalis toxicity
Excessive sweating (or exercising)
People with kidney disease or severe heart disease
should take magnesium supplements ONLY under the direction
of their
medical
practitioner. Which
form of magnesium to take?
Some forms of magnesium, such as magnesium hydroxide, magnesium
oxide, magnesium carbonate, magnesium chloride and magnesium
sulphate (Epsom salts) may cause diarrhoea, and should, in
most cases, be avoided.
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