In brief
A mineral your body needs to regulate muscle and nerve function, blood sugar and blood pressure, and to make protein, bone and DNA.
- Leafy greens, legumes, nuts, seeds and whole grains are good sources.
- Several small studies found magnesium supplements can modestly reduce how often migraines happen.
- High intakes from supplements can cause diarrhoea, nausea and stomach cramps, and magnesium supplements can interact with some medicines.
How it works
Magnesium is a cofactor in more than 300 enzyme systems and is required for energy production. It helps move calcium and potassium across cell membranes, which matters for nerve signals, muscle contraction and a normal heart rhythm. Only about one per cent of the body's magnesium is in the blood, according to Pathology Tests Explained.
The recommended daily intake for adults is between 310 and 420 mg, according to healthdirect. Low magnesium is more likely in older people, people with type 2 diabetes, people with long-term heavy alcohol use and people with gut diseases such as coeliac disease. Symptoms of deficiency include loss of appetite, nausea, tiredness and weakness.
Food sources
- Leafy green vegetables
- Legumes
- Nuts and seeds
- Whole grains
- Seafood
- Milk and yoghurt
From the AskBioMap food guide:
Connections
2 connections on the map. Select a topic to read its page.
Magnesium has been studied for
- Migraine Supported
Several small studies found magnesium supplements can modestly reduce how often migraines happen.
Sources: NIH Office of Dietary Supplements, Magnesium fact sheet for consumers; NIH Office of Dietary Supplements, Magnesium: fact sheet for health professionals
Magnesium is needed for
Magnesium is required for energy production, including oxidative phosphorylation.
Source: NIH Office of Dietary Supplements, Magnesium: fact sheet for health professionals
Lab tests
Medicines and supplements
General education only. Never start, stop or change a medicine without your prescriber.
Sources
- Foods high in magnesium
- Magnesium fact sheet for consumers
- Magnesium: fact sheet for health professionals
- Magnesium
Each connection above names its own source. See every source AskBioMap uses.
Summarised from healthdirect, the NIH Office of Dietary Supplements and Pathology Tests Explained. Sources read on 13 and 19 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.