Your heart beats, your muscles move, and your cells turn food into usable energy. Behind these everyday achievements is magnesium, an essential mineral that rarely gets the spotlight it deserves.
But does that mean everyone needs a supplement? And with citrate, glycinate, and other forms lining the shelves, how do you choose?
The science offers a useful starting point: understand the need before choosing the bottle.
What does magnesium actually do?
Magnesium helps hundreds of enzymes carry out chemical reactions. It supports energy production, protein and DNA synthesis, muscle contraction, nerve signalling and normal heart rhythm. Around 50-60% of the body’s magnesium is stored in bones.[1]
Think of it as part of your body’s essential maintenance crew: involved in many systems, often working quietly in the background.
Start with what’s on your plate
Magnesium is found in nuts, seeds, beans, whole grains, and leafy green vegetables. Building meals around these foods is a practical starting point: try seeds over breakfast, beans in a salad, or greens alongside dinner. Food also provides fibre and other nutrients.[2]
Health Canada recommends 400 mg daily for men aged 19-30 and 420 mg from age 31 onward. Women need 310 mg daily at ages 19-30 and 320 mg from age 31 onward. During pregnancy, recommendations rise to 350-360 mg for adults, depending on age.[3]
These are daily nutrition targets, including food and supplements, not instructions to take that amount in a pill.
When can a supplement make sense?
A supplement can help close a gap when food alone does not meet your needs. Older adults and people with conditions including coeliac disease, Crohn’s disease and type 2 diabetes are more likely to have inadequate magnesium.[2]
Some medicines, including certain water tablets and long-term acid-reducing medicines called proton pump inhibitors, can affect magnesium levels. Still, otherwise healthy people rarely develop symptoms of deficiency from low intake alone.[1]
The useful question is personal: what problem would a supplement help you address? Perhaps your diet needs a little support, or a healthcare professional has identified a deficiency. Knowing the reason makes choosing a product much easier.
Different forms, different considerations
Citrate, oxide, bisglycinate, chloride, lactate and aspartate are different magnesium compounds used in supplements. Their names can seem confusing, but the useful differences come down to absorption, intended use and how well you tolerate them.[2], [4], [5]
Citrate: topping up magnesium and helping things move
Citrate is worth considering when you need more magnesium. In a small study, the body absorbed it more readily than oxide.[4] It is also used in medicines for occasional constipation, where it draws water into the bowel to soften stool.[6]
That can be helpful if you are constipated, but loose stools may be an unwelcome effect if you simply want to top up your intake. Daily supplements and laxative products have different dosing instructions. Follow the label for the product you are using.[6]
Oxide: a supplement with other uses, too
Oxide can help supplement a diet that falls short in magnesium. Some products also use it to relieve heartburn or as a short-term laxative.[7] Although it was less readily absorbed than citrate in one study, that does not make it useless.[4]
The catch? It can cause diarrhoea and cramping. Check what the product is intended for, and ask a pharmacist if heartburn or constipation keeps coming back.[7]
Glycinate/bisglycinate: what about better sleep?
There is some encouraging research here. In a 2025 study of 155 adults with poor sleep, people taking bisglycinate reported slightly greater improvements in insomnia symptoms than those taking a placebo. The study lasted four weeks and used 250 mg of elemental magnesium daily.[5]
That makes bisglycinate worth discussing if sleep is your goal. Keep expectations realistic, though: the benefit was small, and the study did not show that it works better than other forms.[5]
Chloride, lactate and aspartate: other ways to meet your needs
The NIH lists these among the more readily absorbed forms of magnesium taken by mouth.[2] They are useful options to consider when your goal is simply to get enough magnesium. The guidance does not give each one a special job, such as improving sleep or supporting the heart better than the others. The dose and how well the product agrees with you can help guide your choice.
L-threonate: an interesting newcomer to memory research
In a six-week study funded by industry, 100 adults took L-threonate or a placebo. Those taking L-threonate improved on some tests of thinking and memory, but not all. Sleep results were mixed, and sleep-tracking devices showed no benefit.[8]
The findings are worth watching. They do not make L-threonate a proven treatment for dementia or show that it beats other magnesium forms.[8]
Malate: does it help with pain or energy?
The evidence is less convincing than you might hope. A small study in people with fibromyalgia tested magnesium plus malic acid. During the part of the study where treatment was kept hidden from participants and researchers, there was no clear benefit.[9] That study does not prove that magnesium malate relieves pain or gives you an energy boost.
Read the dose as carefully as the name
Look for the amount of elemental magnesium, meaning magnesium itself rather than the weight of the whole compound.[1]
Check whether the amount on the label is for one tablet or the whole daily serving. That small detail makes a big difference when comparing bottles.
For adults, the upper intake level is 350 mg daily from supplements and medicines, excluding magnesium in food and water. That is why your total daily nutrition target can be higher than the supplement limit.[3]
More is not always more helpful
Too much supplemental magnesium can cause diarrhoea, nausea and cramps. People with kidney disease need medical advice before taking it. Magnesium can also interfere with certain antibiotics and osteoporosis medicines, so ask a pharmacist about timing.[1]
Read the directions, consider other supplements you already take, and ask before exceeding the supplemental upper limit. A bigger number on the front of a bottle is not, by itself, a reason to choose it.
Make the choice fit your needs
A sensible choice starts with your diet, your reason for supplementing, the elemental dose and how well you tolerate the product. An impressive list of ingredients is less useful than a clear answer to why you are taking them.
For readers exploring their options, Northinca’s portfolio includes Ana María Lajusticia, a Spanish brand specialising in magnesium and nutritional products. Contact Northinca for current Canadian availability, and apply the same thoughtful approach to choosing a formulation.[10]
1. National Institutes of Health, Office of Dietary Supplements. Magnesium: fact sheet for health professionals [Internet]. Bethesda (MD): NIH; [cited 2026 Oct 20].
2. National Institutes of Health, Office of Dietary Supplements. Magnesium: fact sheet for consumers [Internet]. Bethesda (MD): NIH; [cited 2026 Oct 20].
3. Health Canada. Dietary reference intakes tables: reference values for elements [Internet]. Ottawa (ON): Government of Canada; [cited 2026 Oct 20].
4. Werner T, Kolisek M, Vormann J, Pilchova I, Grendar M, Struharnanska E, et al. Assessment of bioavailability of Mg from Mg citrate and Mg oxide by measuring urinary excretion in Mg-saturated subjects. Magnes Res. 2019;32(3):63-71.
5. Schuster J, Cycelskij I, Lopresti A, Hahn A. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025;17:2027-40.
6. American Society of Health-System Pharmacists. Magnesium citrate [Internet]. MedlinePlus. Bethesda (MD): National Library of Medicine; [cited 2026 Oct 20].
7. American Society of Health-System Pharmacists. Magnesium oxide [Internet]. MedlinePlus. Bethesda (MD): National Library of Medicine; [cited 2026 Oct 20].
8. Lopresti AL, Smith SJ. The effects of magnesium L-threonate (Magtein®) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Front Nutr. 2026;12:1729164.
9. Russell IJ, Michalek JE, Flechas JD, Abraham GE. Treatment of fibromyalgia syndrome with Super Malic: a randomized, double blind, placebo controlled, crossover pilot study. J Rheumatol. 1995;22(5):953-8.
10. Northinca. Health, wellness & beauty brands [Internet]. Richmond Hill (ON): Northinca; [cited 2026 Oct 20].