Magnesium is one of the ‘macrominerals’ – the group of seven main minerals our body needs to function properly. It is one of the most abundant minerals in the body’s cells (second only to potassium). Approximately 60% of the magnesium in our body is stored in bone – the remainder is in muscle, soft tissue and the body fluids.
Magnesium is found in many ‘whole’ foods, including seeds (pumpkin, sunflower, sesame), nuts (almonds, cashews, Brazil nuts), leafy green vegetables, rice bran and oat bran, buckwheat, fish and seafood, seaweeds such as kelp, dried fruits such as figs, apricots and prunes, wholegrains and cocoa. However, levels are often lower than they should be in some foods, due to intensive farming and depletion of minerals in the soil.
What does it do in the body?
Magnesium has many functions in the body. These include:
• Energy production
• Regulating levels of potassium and sodium in the cells (necessary for proper function of the cell)
• Normal heart function
• Absorption of calcium, and regulating calcium levels in the body
• Maintaining normal blood pressure, through allowing the artery walls to relax (vasodilation)
• Forming part of bone structure
• Cell replication
Common reasons for taking magnesium supplements including maintaining a healthy heart and blood pressure, helping energy levels, supporting bone health, helping relaxation of muscles, and helping to support the body when a person is ‘stressed’ for any reason.
When taking a calcium supplement – especially for bone health – we would always advise taking magnesium alongside this, to support the absorption and use of calcium, and to ensure there is a good ratio of calcium to magnesium in the body. See the separate Bone Health category and Calcium category for more details.
How can I take magnesium?
Cheaper forms of magnesium that may be found in supplements include magnesium oxide and magnesium chloride, however these are relatively poorly absorbed. More absorbable forms of magnesium include magnesium citrate, magnesium malate, magnesium fumarate, magnesium glycinate and ‘food form’ magnesium.
Magnesium citrate, although relatively well absorbed, can cause loose stools in some people. A gentler form that shouldn’t have this effect (or for people who have a sensitive digestive system) is magnesium glycinate.
Magnesium is generally found in capsule or tablet form, but can also be found in powder or (rarely) liquid form.