Magnesium

Useful above all if you are starting from a low intake.

• Tier C — Preliminary or mixed — it might work, it might not
• Health

What it is for

Correcting a deficiency; possible support for sleep and muscle function.

How it works

A cofactor in hundreds of enzymatic reactions, including neuromuscular function.

Dosing

Count elemental magnesium. The US adult upper limit is 350 mg/day from supplements and medications unless clinically supervised; magnesium in food is excluded. This is not a target dose.

When to take it

At night if you are after the sleep effect.

Safety

May cause diarrhea; kidney impairment increases the risk of accumulation and toxicity.

Side effects

Diarrhoea with high doses or poorly absorbed forms (oxide).

Interactions

It reduces absorption of some antibiotics (space the doses out).

Contraindications

Kidney failure (seek medical advice).

Who it has been studied in

Useful if your intake is low (which is common).

Frequently asked