Magnesium (Mg)
found in all body tissue
especially bones
Functions
activator for many enzymes
metabolism of carbs, & proteins
proper bone formation
with Ca, P, Vit D
role in nerve cell transmission & muscle contraction
More than 300 enzymes require magnesium ions for their catalytic action, including all enzymes using or synthesizing ATP and those that use other nucleotides to synthesize DNA and RNA. (https://en.wikipedia.org/wiki/Magnesium#Biological_roles)
important for energy production
Sources
milk & meat
medium sources
milling removes much Mg
refine cereals therefore poor source
Plant foods
seeds, legumes, green leafy vegetables, whole grains
Factors affecting absorption
Decreased by
high phosphate intake
excessive calcium intake
foods high in phytate
low protein intake
Deficiency
Aetiology
not common as widely found
Symptoms
associated with
Elderly & patients with severe vomiting
excessive alcohol intak
certain medications
see http://www.magnesiumeducation.com/medications-and-magnesium for a list
protein energy malnutrition
use of diuretics over a long period
neuromuscular & gastrointestinal problems
behaviour changes: delirium, depression, hallucinations, nervousness
may lead to hypocalcaemia & muscle cramps
Excess
high intake of magnesium salts have laxative effect
excess stored in bones rather than excreted
generally not toxic unless kidney function impaired