How Much Magnesium in Pumpkin Seeds? Raw vs. Roasted

A one-ounce serving of pumpkin seed kernels (pepitas) delivers roughly 150 mg of magnesium, covering about 35–40% of most adults’ daily needs. That figure holds whether the seeds are raw or roasted, because minerals like magnesium are not destroyed by heat the way some vitamins are. The more interesting story is what roasting does change, how much the variety and growing conditions of the pumpkin matter, and whether the magnesium in those seeds actually makes it into your bloodstream.

The Raw-Versus-Roasted Numbers

Dried raw pumpkin seed kernels contain approximately 550 to 590 mg of magnesium per 100 grams, depending on the cultivar and database consulted. Roasted seeds land in a very similar range. The reason is straightforward: magnesium is an element. It does not break down or evaporate during cooking the way heat-sensitive molecules like vitamin C or certain B vitamins do. When you roast pumpkin seeds at typical home or commercial temperatures, you drive off moisture, but you do not send magnesium into the air.

That moisture loss actually produces a small concentrating effect. Because roasted seeds weigh slightly less per seed than raw ones, you can end up with marginally more magnesium per gram of roasted seed compared to the same gram of raw seed. In practice, the difference is negligible for a one-ounce handful. You might see a spread of a few milligrams per serving between raw and roasted on different nutrition labels, but that gap is smaller than the natural variation between two different bags of seeds from different farms.

Where the numbers can genuinely diverge is with whole pumpkin seeds versus shelled kernels. Whole seeds, meaning the kind with the white hull still attached, contain more fiber but somewhat less magnesium per ounce, because the hull itself contributes weight without contributing much magnesium. Shelled kernels (pepitas) are the denser magnesium source. Most nutrition databases reporting those high magnesium figures are referring to shelled kernels, so if you are eating hull-on seeds, adjust your expectations downward slightly.

Why the Variety of Pumpkin Matters

Not all pumpkin seeds carry the same mineral load. Research comparing different Cucurbita cultivars has found that magnesium content varies meaningfully by variety. A study examining three cultivars found that the Jacarezinho variety stood out for its magnesium content, while others were richer in calcium, potassium, or phosphorus instead.¹ Another study comparing indigenous and hybrid pumpkin varieties found no significant difference in magnesium between the two, suggesting that some cultivar pairs are closer together while the broader species pool shows real spread.²

This means the “550–590 mg per 100 g” range you see in food composition databases represents an average across commercially common varieties. The pumpkin seeds at your local store, which are typically from hull-less or “Styrian” type varieties bred specifically for snacking, tend to sit at the higher end. Heritage varieties grown in a backyard garden could land higher or lower depending on the specific cultivar.

Soil conditions add another layer of variability. Magnesium in seeds comes from magnesium in the soil the plant grew in, and modern intensive farming practices can deplete soil magnesium over time. A review on crop biofortification found that soil acidification, nutrient imbalances, and heavy agricultural use all limit how much magnesium plants can take up and deposit in their seeds.³ So two identical cultivars grown on different farms could produce seeds with different magnesium concentrations, and seeds from mineral-rich soils will generally outperform those from depleted fields.

How Pumpkin Seeds Compare to Other Magnesium Sources

Pumpkin seeds are consistently among the richest commonly eaten sources of magnesium. A Serbian study analyzing the nutritional profiles of various nuts and seeds found that a single recommended portion of pumpkin seeds contributed about 32% of the nutrient reference value for magnesium, putting them near the top alongside hemp seeds. For comparison, the same portion of almonds contributed about 20%, hazelnuts about 19%, and walnuts about 14%.⁴

Brazil nuts came in higher than almonds in that analysis (about 28% of the reference value per portion), but they still fell short of pumpkin seeds. Among seeds specifically, hemp seeds were the only competitor in the same tier. Sunflower seeds, flaxseeds, and chia seeds all contain respectable amounts of magnesium, but pumpkin seeds tend to edge them out per serving in most food composition comparisons.

This makes pumpkin seeds a practical tool if you are trying to close a magnesium gap through diet. Most adults in developed countries fall short of the recommended daily intake, which sits around 310–320 mg for women and 400–420 mg for men. A single ounce of pepitas covers a third or more of that in one handful, which is hard to match with any other single food outside of supplements.

Phytate and Whether You Actually Absorb That Magnesium

The raw magnesium content on a label does not tell the whole story, because pumpkin seeds also contain phytate, a compound that binds minerals in the gut and reduces how much your body absorbs. This is where the raw-versus-roasted question gets more interesting than the mineral count alone would suggest.

Roasting reduces phytate. A study on roasted pumpkin seeds (specifically Telfairia occidentalis, a related species known as fluted pumpkin) found that phytate concentrations dropped steadily with longer roasting times, falling from about 425 to 175 units over the processing period.⁵ That is a reduction of more than half. The same study found that other anti-nutrients like oxalate and cyanide also declined with roasting, though less dramatically.

This matters because even if raw and roasted seeds contain roughly the same total magnesium, your body may absorb more from the roasted version thanks to that lower phytate load. How much more is hard to pin down precisely, because absorption also depends on what else you ate that day, your gut health, and your existing magnesium status. But the direction is clear: roasting works in your favor for mineral bioavailability.

Other traditional food preparation methods also reduce phytate. Soaking, sprouting, and fermenting seeds before eating them all break down phytate to some degree. If you prefer raw seeds and want to improve absorption, soaking them overnight in water is a low-effort option. It will not achieve the same phytate reduction as thorough roasting, but it helps.

Food Sources Versus Supplement Tablets

One concern people have is whether they would be better off just taking a magnesium supplement instead of eating seeds. The research here is surprisingly favorable toward food. A study measuring magnesium absorption from almonds (another high-magnesium food) versus a soluble magnesium supplement found that the magnesium from the food was absorbed just as well. More striking, magnesium from a commercially available enteric-coated supplement was absorbed significantly worse than either the food or the soluble supplement form.⁶

That finding has practical implications. Not all supplement forms are equivalent, and some of the cheaper, coated magnesium tablets on store shelves may deliver less usable magnesium than a serving of pumpkin seeds. Foods also come bundled with co-nutrients: the zinc, iron, phosphorus, healthy fats, and fiber in pumpkin seeds all arrive together and can influence each other’s absorption and metabolic effects. A supplement delivers isolated magnesium without that broader nutritional context.

None of this means supplements are worthless. People with diagnosed deficiency, certain medical conditions, or medications that deplete magnesium may genuinely need supplemental doses that are impractical to get from food alone. But for someone whose goal is simply to meet the daily recommendation, a handful of pumpkin seeds each day is a surprisingly efficient approach, and the magnesium you absorb from them holds up well against what a pill provides.

What Roasting Does to Everything Else in the Seed

Since magnesium itself barely budges with roasting, the real question for someone choosing between raw and roasted is what happens to the other nutrients. The picture is mixed.

Vitamin E (tocopherols) takes a hit during the early stages of roasting. Research tracking the chemical changes in pumpkin seeds during roasting for oil production found that vitamin E levels dropped by about 30% during the first 40 minutes of roasting. Interestingly, the levels then climbed back up during the last phase of roasting to roughly where they started.⁷ That U-shaped pattern likely reflects vitamin E being consumed as an antioxidant during heat stress, then released from cellular structures as roasting continues. For home-roasted seeds baked at moderate temperatures for 15–20 minutes, the vitamin E loss is probably modest.

The fatty acid profile remains relatively stable during roasting. The same study found that linoleic acid, the dominant polyunsaturated fat in pumpkin seeds, dropped only from about 54.6% to 54.2% of total fat after roasting. That is essentially unchanged. Pumpkin seeds are not like delicate fish oils that deteriorate quickly with heat; their fat profile holds up well at the temperatures used for roasting seeds.

On the fat-stability front, roasting actually provides a benefit. Oil extracted from roasted pumpkin seeds resists oxidation (going rancid) more effectively than oil from raw seeds when both are exposed to heat. One study found that unroasted seed oil lost polyunsaturated fatty acids much faster under heating than oil from seeds that had been microwave-roasted before pressing.⁸ The Maillard reaction products formed during roasting appear to act as natural antioxidants that protect the fat from breaking down.

Storing Pumpkin Seeds Without Losing Quality

Whether raw or roasted, pumpkin seeds contain enough unsaturated fat to eventually go rancid if stored carelessly. The good news is they are fairly forgiving compared to many other oily seeds.

Research on roasted pumpkin seed oil found that oxidation progressed slowly when the oil was kept in the dark, with key rancidity markers staying well below regulatory limits over a 20-week period. Light exposure, however, accelerated spoilage substantially. Clear bottles were the worst offenders, while amber glass provided effective protection against UV-driven oxidation.⁹

For whole seeds rather than extracted oil, the same principles apply at a practical level. Keep them in an opaque, airtight container, away from heat and light. A cool pantry works for a few weeks to a couple of months. For longer storage, the refrigerator or freezer extends shelf life considerably. Roasted seeds do tend to lose their crunch over time as they absorb ambient moisture, but that is a texture issue, not a mineral issue. The magnesium in a slightly stale pumpkin seed is the same as in a freshly roasted one.

Metabolic Benefits Beyond the Mineral Count

Pumpkin seeds are often recommended as a magnesium source, but their health effects extend well past any single mineral. Research has examined the broader metabolic impact of regular consumption, and the results are encouraging.

In animal studies, pumpkin seed protein improved a cluster of metabolic markers in rats fed a high-fructose diet designed to induce metabolic syndrome. The seed protein improved glucose and insulin levels, lowered blood pressure and triglycerides, and reduced oxidative stress in the liver and kidneys.¹⁰ These are rodent results and do not translate directly to humans, but they point toward pumpkin seed components having effects that go beyond what you would expect from their mineral content alone.

Human data exists too, though it remains limited. A clinical study in obese women found that adding pumpkin seed flour to a calorie-restricted diet led to greater improvements in body fat, triglycerides, and insulin resistance compared to the diet alone.¹¹ The improvements in insulin and fat mass were statistically significant, suggesting that something in the seed, whether the protein, the fat, the fiber, or the combination, contributes meaningfully to metabolic health in the context of a controlled diet.

Whether magnesium is the main driver of those benefits, a contributing factor, or mostly along for the ride is hard to untangle. Magnesium itself plays a role in insulin sensitivity and blood pressure regulation. But pumpkin seeds also deliver zinc, polyunsaturated fats, plant sterols, and a range of polyphenols. Trying to credit any one component misses the point: the seed works as a package, and that package appears to do useful things for metabolic health.

Salted, Seasoned, and Flavored Varieties

Most commercially roasted pumpkin seeds come with added salt, and many now come in flavored coatings ranging from cinnamon sugar to sriracha. These additions do not change the magnesium content of the seed kernel itself, but they do change the overall nutritional profile of what you are eating.

Sodium is the most obvious concern. A heavily salted serving of roasted pumpkin seeds can deliver 150–300 mg of sodium per ounce, which eats into your daily budget if you are watching salt intake. Unsalted roasted seeds are widely available and nutritionally almost identical to raw seeds in their mineral content, making them the simplest option if your primary goal is magnesium without extra sodium.

Sugar-coated and flavored varieties add calories and carbohydrates while potentially diluting the per-gram magnesium density, because the coating adds weight that is not pumpkin seed. If a coated seed weighs 30% more than a plain kernel, your one-ounce portion contains less actual seed and therefore less magnesium. This effect is modest but worth knowing about if you are choosing pumpkin seeds specifically as a mineral source rather than purely as a snack.

For cooking, pumpkin seeds are remarkably heat-stable. You can toast them in a dry skillet or oven without worrying about destroying their magnesium, and the improved crunch and flavor often make people eat more of them. Tossing them into salads, grain bowls, or yogurt is a simple way to add magnesium to meals you are already eating. The magnesium survives any normal kitchen treatment, so the best preparation method is whichever one gets you to eat them consistently.