Magnesium Rich Foods — and the Australian Seed Measured at 421mg per 100g

Magnesium is a cofactor in more than 300 enzyme systems in the human body. That is not a marketing claim — it is the National Institutes of Health’s own figure for how many biochemical processes depend on this one mineral. [1] Protein synthesis, muscle and nerve function, blood glucose regulation, energy production, blood pressure, DNA synthesis — all of them require magnesium to run.

Most Australians do not get enough of it. The daily recommended intake is 310–420mg depending on age and sex. The problem is not that magnesium is rare — it is that the foods highest in it tend to be eaten in small amounts, and the supplement market has turned it into a confusing list of types with competing claims.

This page covers which foods actually contain the most magnesium, what the different types mean, and why the Kakadu plum seed — at 421mg per 100g — ranks alongside the world’s highest-magnesium seeds.

Kakadu Plum Capsules — whole fruit and seed, 64 cents each →

Magnesium Rich Foods — What 100g Actually Looks Like

Nutritional tables always list magnesium per 100g. The problem is that 100g means something different for every food. Here is the same data with real serving sizes and what percentage of the adult daily intake (420mg) each serving provides:

The adult recommended daily intake is 310–320mg for women and 400–420mg for men (Australian NHMRC). [2]

Seeds dominate the top of the list because seeds are the plant’s nutrient store — everything the plant needs to grow a new plant is packed into the seed. Kakadu plum seed kernel at 421mg per 100g sits behind pumpkin and hemp seeds but ahead of every other common food. A tablespoon of the dried seed kernel powder (15g) delivers 63mg — about 15% of the daily intake in one serving.

What Type of Magnesium Is In Food?

The supplement market sells magnesium under at least seven different names. Before deciding which is “best”, it helps to understand what they are — and how food magnesium compares.

The 7 supplement types

• Magnesium glycinate (bisglycinate) — magnesium bonded to glycine, an amino acid. Well absorbed, gentle on the stomach. Most commonly recommended for sleep and anxiety. The most searched magnesium supplement in Australia.
• Magnesium citrate — bonded to citric acid. Good absorption. In higher doses, has a mild laxative effect. One of the best-studied forms.
• Magnesium malate — bonded to malic acid. Used in energy research and fibromyalgia studies. Malic acid is involved in the energy cycle (Krebs cycle).
• Magnesium threonate — a newer form that crosses the blood-brain barrier more readily than others. Studied for cognitive support and memory.
• Magnesium oxide — the cheapest form. Low absorption (around 4%). Mainly used for constipation rather than general supplementation.
• Magnesium chloride — used topically and transdermally (Epsom salts for soaking). Some absorption through skin.
• Magnesium taurate — bonded to taurine. Studied for cardiovascular support and blood pressure.

What type is in food?

None of the above. In food, magnesium is not manufactured into a named chemical form — it arrives naturally complexed within the food matrix. In seeds, there are two main natural forms:

Protein-chelated magnesium. Seeds are high in protein, and magnesium naturally bonds to amino acid side chains in the food matrix as the seed is digested. This is essentially the same mechanism that magnesium glycinate is engineered to replicate — magnesium bonded to amino acids for better absorption. In the seed, it happens without the manufacturing step. Kakadu plum seed kernel is 32% protein. [3]

Chlorophyll-bound magnesium. Magnesium is the atom at the centre of every chlorophyll molecule — the green pigment in plants. It sits in a porphyrin ring structure, giving chlorophyll its shape and function. Kakadu plum contains 19.49mg of chlorophyll per 100g. [3] This form of magnesium is found only in green plant foods; no supplement on the market replicates the Mg-porphyrin complex.

Additionally: seeds contain phytic acid, which can bind to minerals and reduce their absorption. The evidence-based counteract for phytate is vitamin C — it is one of the dietary factors known to enhance mineral absorption from plant foods. [4]

Why Kakadu Plum Seed Is Unusual

Most high-magnesium seeds — pumpkin, hemp, flaxseed — are eaten as foods on their own. Their magnesium is in the seed, and that is the whole story.

Kakadu plum seed is different because of what it grows inside. The fruit itself contains the highest recorded natural vitamin C of any fruit tested — our independently lab-tested powder measures 12,100mg per 100g, more than 240 times the concentration of a fresh orange. One 500mg capsule delivers 60mg of vitamin C. [5]

A single capsule therefore contains both the seed (with its protein-chelated, chlorophyll-form magnesium) and a meaningful dose of the vitamin C that supports mineral absorption from the same dose. No pumpkin seed or hemp seed delivers vitamin C alongside the minerals.

The seed also carries calcium (539mg/100g), phosphorus (873mg/100g), potassium (669mg/100g), zinc (6.0mg/100g — 10 times the fruit flesh), copper (2.5mg/100g — 8 times), and manganese (9.1mg/100g). These minerals do not arrive in isolation — they arrive with 32% protein, 35% fat (four-fifths unsaturated), 21% fibre, and the full polyphenol profile of the whole fruit. [3]

Why Our Capsules Contain the Whole Fruit — Seed and All

Most Kakadu plum supplements use only the dried fruit flesh. Ours uses whole fruit powder — fruit and seed kernel together, ground to the same fine consistency throughout, with no grit. The seed kernel is processed to the same powder standard as the fruit. That costs more and takes more work.

We do it because the seed is the most mineral-dense part of the plant, and leaving it out means leaving out the most nutritionally significant part of the ingredient. No other Kakadu plum supplement we are aware of includes the seed kernel.

Kakadu Plum Capsules — whole fruit and seed, 140 capsules, 64 cents each →

For the full picture of what is in the fruit — antioxidants, tannins, vitamin C, vitamin E — see our antioxidant rich foods page and our tannins page.

Frequently Asked Questions

What foods are highest in magnesium?

The foods with the highest magnesium per 100g are seeds and nuts: pumpkin seeds (534mg), hemp seeds (483mg), Kakadu plum seed kernel (421mg), flaxseeds (392mg), and almonds (270mg). Dark chocolate contains 228mg per 100g. Cooked spinach contains 79mg per 100g but a full 180g serving delivers about 142mg — around a third of the adult daily intake. Avocado contains 29mg per 100g. Most people fall short of the recommended 320–420mg per day because the highest-magnesium foods — seeds and nuts — tend to be eaten in small quantities.

What type of magnesium is best?

The most widely studied and sold magnesium supplement types are: magnesium glycinate (bound to the amino acid glycine — well absorbed, gentle on the stomach, often recommended for sleep and anxiety), magnesium citrate (bound to citric acid — good absorption, mild laxative effect in higher doses), magnesium malate (bound to malic acid — used in energy and muscle research), magnesium threonate (crosses the blood-brain barrier — studied for cognitive function), magnesium oxide (cheap, low absorption — mainly used for constipation), magnesium chloride (used topically and transdermally), and magnesium taurate (bound to taurine — studied for cardiovascular support). In food, magnesium does not come in these synthetic forms — it arrives naturally complexed within the food matrix, alongside proteins, fats, fibre and other minerals.

Is food magnesium better than supplements?

Food and supplements serve different purposes. Foods deliver magnesium alongside the co-factors the body uses to absorb and use it — protein, fibre, vitamin C and other minerals. Seeds like pumpkin seeds and Kakadu plum seed deliver magnesium naturally complexed with proteins (the same mechanism chelated supplements like glycinate try to replicate), alongside fat, fibre and other minerals. Supplements deliver a concentrated isolated dose — useful when dietary intake is consistently low. For most people with a varied diet, food sources of magnesium have the advantage of arriving in context. Vitamin C in particular enhances mineral absorption from plant foods — which is why a food high in both magnesium and vitamin C provides a natural absorption advantage.

What does magnesium do in the body?

Magnesium is a cofactor in more than 300 enzyme systems in the human body — the National Institutes of Health’s own figure. These enzyme systems regulate protein synthesis, muscle and nerve function, blood glucose control, blood pressure, and energy production. Magnesium is required for the synthesis of DNA and RNA. It contributes to normal bone structure (about 60% of the body’s magnesium is in bone). It supports normal muscle function including the heart. Magnesium deficiency is associated with fatigue, muscle cramps, and poor sleep, though these symptoms have many causes.

What is magnesium glycinate?

Magnesium glycinate (also called magnesium bisglycinate) is a synthetic supplement form where magnesium is chemically bonded to glycine, an amino acid. The chelation — bonding to an amino acid — is designed to improve absorption compared to cheaper forms like magnesium oxide, and to be gentler on the digestive system. It is one of the most widely searched magnesium supplement types and is commonly recommended for sleep, anxiety and general supplementation. In food, magnesium arrives naturally chelated to proteins (including their constituent amino acids such as glycine) when the food is digested — seeds high in protein deliver magnesium in a functionally similar way, without the supplement manufacturing step.

How much magnesium do you need per day?

Australian NHMRC Recommended Dietary Intakes: adult women 310–320mg per day, adult men 400–420mg per day. Pregnant women 350–360mg. The upper tolerable intake from supplements is 350mg per day — above that, digestive side effects (particularly loose stools) become likely. Most Australians consume less than the recommended amount. A 28g handful of pumpkin seeds provides about 150mg — around a third to a half of the daily intake. A 28g handful of almonds provides about 76mg. A tablespoon (15g) of Kakadu plum seed kernel powder provides about 63mg — around 15% of the daily intake.

Does vitamin C help magnesium absorption?

Vitamin C is one of the dietary factors that helps the body absorb minerals from plant foods. In seeds, a portion of the magnesium is bound to phytic acid (phytate) — an organic acid that can reduce mineral absorption. Vitamin C reduces the inhibitory effect of phytate on mineral uptake. Foods that combine high mineral content with high vitamin C — like Kakadu plum, which contains 421mg of magnesium per 100g of seed kernel and is part of a whole fruit with exceptional vitamin C content — are unusual in providing both the mineral and its absorption enhancer together.

For the plant protein comparison — where the Kakadu plum seed’s 32% protein sits against chickpeas, lentils, soy, and hemp — see our plant based protein page.

For the complete nutritional profile of the seed kernel — including protein, fat, and the four mineral co-factors the fruit flesh uses to build collagen — see our Kakadu plum seed page.

References

1. National Institutes of Health Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
2. National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand. Australian Government, 2006 (updated 2017).
3. Konczak I, Zabaras D, Dunstan M et al. Health Benefits of Australian Native Foods. RIRDC (Australian Government) Pub. No. 09/133, Sept 2009.
4. Hallberg L, Brune M, Rossander L. The role of vitamin C in iron absorption. Int J Vitam Nutr Res Suppl. 1989;30:103–8. (The vitamin C and mineral absorption relationship is documented across multiple reviews.)
5. Phytoverse Australia. Certificate of Analysis — Terminalia ferdinandiana (Kakadu Plum) Whole Fruit Powder. 12,100mg/100g ascorbic acid (HPLC). Held on file.

Our products are food, not therapeutic goods, and are not intended to diagnose, treat, cure or prevent any disease or condition.