Magnesium Hi-Zorb

Magnesium suits most people, and the handful of situations that need a conversation first are easy to spot. So here is the same quick triage our naturopaths run at the counter every day, in the order they run it.

A good fit if

• Your usual diet is light on wholegrains, legumes, nuts, seeds and green leafy vegetables. The foods that carry most dietary magnesium
• You are an older adult, or eating a narrow or highly processed diet, where intakes commonly sit below the RDI
• You are pregnant or breastfeeding, when reference intakes are higher than usual, and you are working alongside your midwife or doctor
• You found a cheap magnesium oxide blend hard to tolerate and want a better-absorbed, gentler form
• Your kidney function is normal and you take no medicines that need to be kept apart from a mineral dose

Check with us first if

• Taking a bisphosphonate. Magnesium can bind it, so separate the magnesium dose from the bisphosphonate by at least two hours.
• Taking a tetracycline or quinolone antibiotic. Take magnesium at least two hours before, or four to six hours after, the antibiotic.
• On loop or thiazide diuretics, or on a proton pump inhibitor long term. Magnesium status can be pushed in either direction on these medicines, and it is worth reviewing with the prescriber.
• Prone to loose bowels. Magnesium carbonate, chloride, gluconate and oxide are the forms most often linked to diarrhoea, and minor gastrointestinal side effects occurred in 11–37% of people taking magnesium across Cochrane's cramp trials. Form and split dosing usually solve it.
• Taking any prescription medicine at all. A quick check with your doctor, pharmacist or our naturopaths first is the sensible step.

• Magnesium glycinate (bisglycinate). Best known for: Being gentle on the stomach. The usual pick when a larger dose is wanted without loose bowels. Absorption: Good. Chelated to the amino acid glycine and among the forms least associated with diarrhoea. Typical use: Everyday topping-up of intake, and a popular evening choice.
• Magnesium citrate. Best known for: Being one of the best-absorbed everyday forms; at larger doses it also draws water into the bowel. Absorption: High. Absorbed more completely than oxide or sulfate in human studies. Typical use: General daily use in tablets, capsules and powders.
• Magnesium oxide. Best known for: Carrying the most magnesium per milligram of compound, and costing the least. Absorption: Poor. One review cites absorption as low as about 4% in humans. Typical use: Common as a low-cost bulk ingredient in blends; frequently associated with diarrhoea.
• Magnesium L-threonate. Best known for: Being marketed as the 'brain' form for cognition and sleep. Absorption: Adequate, but the claim that it raises magnesium in the brain specifically rests mainly on animal studies. Typical use: Cognition and sleep positioning. Human trial evidence is small and early. Treat the marketing with caution.
• Magnesium chloride. Best known for: Dual use. Taken orally, and sold as bath flakes and topical oils. Absorption: Good when taken orally. Evidence for meaningful absorption through the skin is lacking. Typical use: Oral supplements, plus flakes and sprays where the benefit is largely the ritual, not proven uptake.
• Magnesium taurate. Best known for: Being paired with taurine and positioned for heart health and calm. Absorption: Presumed good, but head-to-head human absorption data is scarce. Typical use: Often chosen for the taurine as much as the magnesium. Form-specific evidence is thin.
• Magnesium orotate. Best known for: Being paired with orotic acid and positioned for cardiac and athletic use. Absorption: Not well characterised in comparative human studies. Typical use: Niche and comparatively expensive. Human research is limited and mostly in clinical populations.

Reference values. NHMRC Nutrient Reference Values (RDI unless noted): infants 0–6 months 30 mg/day and 7–12 months 75 mg/day (Adequate Intake); 1–3 years 80 mg; 4–8 years 130 mg; 9–13 years 240 mg; males 14–18 years 410 mg; females 14–18 years 360 mg; males 19–30 years 400 mg and 31+ years 420 mg; females 19–30 years 310 mg and 31+ years 320 mg. Pregnancy 350–400 mg depending on age; breastfeeding 310–360 mg depending on age.

Typical supplemental range. Australian labels commonly provide somewhere between about 100 mg and 400 mg of elemental magnesium per daily dose, often split across two or three doses. Read the elemental magnesium figure, not the weight of the compound. '750 mg magnesium glycinate' is not 750 mg of magnesium.

Upper level. NHMRC Upper Level of Intake for magnesium from supplements: 350 mg/day from age 9 years upward, 110 mg/day for ages 4–8, and 65 mg/day for ages 1–3. Not established for infants, where intake should come from breast milk, formula and food only. The Upper Level covers supplements and medicines only. It does not include magnesium occurring naturally in food and drink.

Worth knowing. These figures are population reference values, not a dose for any one person. Your needs depend on your age, diet and health circumstances. Talk to one of our naturopaths.

Food first, where the diet allows it.

• Pumpkin seeds: about 156 mg per 28 g
• Chia seeds: about 111 mg per 28 g
• Almonds, dry roasted: about 80 mg per 28 g
• Spinach, cooked: about 78 mg per half cup
• Cashews, dry roasted: about 74 mg per 28 g
• Black beans, cooked: about 60 mg per half cup

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• Reduced kidney function or kidney failure. Excess magnesium cannot be cleared and can accumulate; do not supplement without medical supervision.
• Bisphosphonates. Separate the magnesium dose by at least two hours.
• Tetracycline or quinolone antibiotics. Magnesium at least two hours before, or four to six hours after, the antibiotic.
• Loop or thiazide diuretics, or long-term proton pump inhibitors. Magnesium status worth reviewing with the prescriber.
• Tendency to loose bowels. Carbonate, chloride, gluconate and oxide are the forms most often linked to diarrhoea.
• Infants under 12 months. The affected inorganic magnesium salts must not be directed for use under 12 months of age.
• Exceeding the label dose. Extremely high intakes can lead to irregular heartbeat and cardiac arrest.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.