Magnesium is an essential mineral involved in bone mineralisation, normal muscular contraction, maintenance of heart muscle and nerve impulse transmission.
Why you may need magnesium
High blood pressure (hypertension) – evidence indicates that magnesium reduces blood pressure.
Diabetes – magnesium assists glucose transport. Low magnesium levels have been reported in people with diabetes mellitus.
Premenstrual syndrome – reduced magnesium levels have been reported in women affected by premenstrual syndrome. There is some evidence that magnesium supplementation can improve symptoms including mood changes, cramping and fluid retention.
Migraine – magnesium is shown to be effective in reducing the frequency and duration of migraines.
Osteoporosis – magnesium is a constituent of bone and supplementation has been shown to increase bone density in individuals with osteoporosis.
Fibromyalgia – can help to decrease fibromyalgia related pain and tenderness.
Kidney stones – magnesium can help to prevent the recurrence of kidney stones. Magnesium in combination with vitamin B6 also seems to decrease urinary oxalate levels in people with hyperoxaluria (high urinary oxalate) who have previously had kidney stones.
Attention deficit-hyperactivity disorder (ADHD) – reduced magnesium levels have been reported in children with ADHD.
Multiple sclerosis (MS) – evidence suggests that magnesium may reduce limb weakness associated with MS.
Restless leg syndrome – magnesium may decrease the amount of movement.
How much to use
Recommended Daily intake (RDI)
Adults over 19 years: 320mg (women), 420mg (men) daily
Pregnancy 19-30 years: 350mg daily
Pregnancy 31-50 years: 360mg daily
Breastfeeding 19-30 years: 310mg daily
Breastfeeding 31-50 years: 320mg daily
Children 9-13 years: 240mg daily
Children 14-18 years: 360mg (girls), 410mg (boys) daily
Symptoms of deficiency
Deficiency symptoms of magnesium include muscle spasm and cramps, bizarre muscle movements or twitches such as eye and face muscles, muscle weakness, chronic pain, insomnia, anxiety, irritability, lethargy, convulsions, anorexia, nausea, vomiting, abdominal pain, kidney stones, cardiac arrhythmias, tachycardia.
The best dietary sources include green leafy vegetables, almonds and other nuts, brewer’s yeast, wholegrain cereals, dairy and dark chocolate.
Other reasons why you may need more
Factors that may increase your demand for more magnesium include alcoholism, diabetes, malabsorption syndromes, impaired parathyroid hormone, activity, excessive coffee, fat and sugar intake, diarrhoea, chronic fatigue syndrome, athletes, excessive sweating, stress, pregnancy and lactation.
- Magnesium is generally well tolerated. Side effects that have been reported include nausea, vomiting, and diarrhoea.
- If you have reduced kidney function magnesium may increase the risk of hypermagnesemia. Consult your healthcare professional before supplementing with magnesium.
- If you have diabetes or hypertension, consult your healthcare professional before supplementing with magnesium.