Magnesium deficiency

• Discuss symptoms and losses. Mention lasting diarrhoea, illnesses and medicines; a clinician interprets blood results alongside your symptoms. [1] [2]
• Address the cause. A confirmed shortage may call for reducing losses, improving food and sometimes replacing magnesium with medical follow-up. A daily food guideline is not a treatment dose. [1] [2]
• Separate cramps from deficiency. Magnesium is unlikely to prevent ordinary cramps in older adults; those studies did not test treating proven deficiency. [3]

Weakness, tiredness, tingling or cramps may occur with low magnesium, but also with other conditions. Severe disturbance can involve an irregular heartbeat or seizures. Seek assessment for persistent symptoms, and mention diarrhoea and medicines. [1] [2]

Seizures, fainting or palpitations with chest pain need urgent medical help. Do not keep raising a home supplement dose. [2]

Apart from low intake, losses through long-term diarrhoea or urine and impaired bowel absorption can contribute. MedlinePlus lists poorly controlled diabetes, alcohol-related illness, malnutrition and digestive conditions among relevant factors. Some diuretics and prolonged use of acid-suppressing medicines may also play a role.[2]

Kidney disease complicates the picture: kidneys regulate magnesium excretion, but reduced elimination can cause magnesium-containing products to raise blood levels too far. Do not stop prescribed medicines on suspicion; discuss their possible contribution with your prescriber.[2]

A clinician may order a blood magnesium level together with values such as potassium or calcium, and sometimes urine tests to investigate losses. The indication depends on symptoms, medicines and underlying conditions. An online symptom list or a trial of home supplements cannot establish the cause.[2]

MedlinePlus notes that a normal blood result does not completely exclude low tissue stores and that an abnormal result needs clinical history and other tests for interpretation. This is not a reason to discard every normal test: ask for a contextual explanation rather than imposing a self-chosen ‘optimal’ threshold.[2]

Wholegrain bread, other grains, vegetables, nuts and dairy provide magnesium. Dutch daily food advice is 350 mg for adult men and 300 mg for adult women, including during pregnancy and breastfeeding. These are not doses for treating a confirmed shortage. [1]

For a confirmed shortage, a clinician chooses care based on severity and cause: reducing ongoing loss, improving food and, if needed, replacing magnesium with follow-up. Severe symptoms call for medical care, not self-treatment. See dietary magnesium for food sources. [1][2]

Trials mostly involving older people with ordinary cramps found magnesium unlikely to prevent them meaningfully. Pregnancy results remain uncertain and eligible exercise-cramp trials were absent. These are not trials of replacing a diagnosed shortage. [3]

Supplements can cause diarrhoea. The Dutch 250 mg daily limit is for extra magnesium from ordinary supplements, not food and not a deficiency treatment prescription. Kidney disease can allow magnesium to accumulate. [1] [2]