Magnesium, a mineral involved in approximately 300 crucial bodily functions, has surged in popularity as a supplement. Holland and Barrett reported selling 45 million magnesium capsules in 2025, and the global market is projected to nearly double in the next decade. This mineral is essential for cell, organ, and brain function, as well as maintaining muscle, nervous system, and immune system health, and stabilizing mood.
Research suggests that magnesium supplementation may help reduce blood pressure. However, many individuals do not consume adequate amounts through their diet, which typically includes nuts, seeds, mackerel, and dark leafy greens. Studies indicate that nearly 60 percent of Britons may be magnesium-deficient.
Recommended Intake and Safety
The NHS recommends a daily intake of around 270mg for women aged 19-64 and 300mg for men in the same age group. Magnesium-rich foods like almonds, cashew nuts, pumpkin seeds, kale, spinach, oats, and legumes can contribute to this intake. Even two squares of 85% cacao dark chocolate can provide about 100mg of magnesium.
While supplements are available, experts advise that not everyone needs them. Senior nutritionist Alex Glover notes that supplementation can be beneficial for those struggling to meet daily requirements through diet alone. However, the NHS advises limiting intake to 400mg per day to avoid potential side effects like diarrhea, and at higher doses, possible blood pressure and heart rhythm issues.
Sleep and neurology specialist Dr. Hanul Bhandari emphasizes that supplements are most effective for correcting deficiencies and relieving symptoms, offering no additional benefits if magnesium levels are already normal. Individuals with heart block, myasthenia gravis, or kidney disease should consult a doctor before taking magnesium supplements.
Types of Magnesium Supplements
Choosing the right magnesium supplement can be confusing due to various forms like glycinate, citrate, and L-threonate, each with different absorption rates and uses.
- Magnesium Glycinate: Often chosen for sleep support, glycinate aids in normal nerve and muscle function, potentially promoting relaxation. Studies suggest it can improve sleep quality and reduce the time it takes to fall asleep, particularly for those with lower baseline magnesium levels. It also plays a role in regulating melatonin and supporting GABA, a calming neurotransmitter.
- Magnesium Taurate: Along with glycinate, taurate is noted for its benefits to heart health and blood pressure regulation. Magnesium helps relax and widen blood vessel walls, potentially lowering blood pressure, with notable effects observed in individuals with existing high blood pressure or low magnesium.
- Magnesium Citrate: This form can act as a laxative while also increasing the body's magnesium reserves. However, it may cause digestive upset in some individuals. It is often recommended to take magnesium citrate with food to mitigate these effects.
- Magnesium L-Threonate: Marketed for cognitive health, this form is designed to cross the blood-brain barrier. Research indicates magnesium's importance for neurological health, and some studies suggest L-threonate may improve cognitive function, including memory. However, human research in this area is more limited.
- Antacids: Some antacids contain magnesium compounds like magnesium hydroxide, carbonate, or trisilicate, designed for immediate relief of heartburn and indigestion by neutralizing stomach acid. Magnesium hydroxide is also a common ingredient in laxatives.
Timing and Other Forms
Magnesium supplements can generally be taken at any time of day, though many find taking them in the evening beneficial due to their calming effects. This can also help alleviate symptoms of restless legs syndrome. Magnesium creams, bath salts, and sprays are also used for localized benefits, particularly for muscle cramps, due to their absorption.
For magnesium citrate, taking it with meals is advised to help prevent stomach upset, nausea, and diarrhea.
