Calling a seed ‘mineral-rich’ is incomplete unless you name the mineral. Hemp stands out for magnesium, whole sesame for calcium and iron, and chia ranks especially high for calcium.
The table uses 30 g portions and unsalted references. The forms are stated because they are not perfectly identical: hemp is hulled while the sesame reference is whole and dried.
| 30 g | Magnesium | Calcium | Iron |
|---|---|---|---|
| Hulled hemp | 210 mg | 21 mg | 2.4 mg |
| Raw pumpkin seeds | 150 mg | 11 mg | 2.5 mg |
| Whole dried sesame | 105 mg | 293 mg | 4.4 mg |
| Dried chia | 101 mg | 189 mg | 2.3 mg |
| Raw sunflower kernels | 91 mg | 35 mg | 1.3 mg |
Magnesium: hemp and pumpkin seeds
Hulled hemp provides about 700 mg magnesium/100 g and pumpkin seeds about 500 mg. Thirty grams supplies roughly 210 and 150 mg. Sesame and chia both land near 100–105 mg per 30 g.
Calcium: whole sesame needs context
At 975 mg/100 g, whole sesame clearly leads this table, followed by chia at 631 mg. But much of sesame’s calcium sits in the hull. A hulled tahini can contain dramatically less, so the whole-seed number should not be transferred to every sesame product.
Iron: sesame, then pumpkin and hemp
Whole sesame provides about 14.6 mg iron/100 g; pumpkin seeds 8.36 mg; hemp 7.95 mg; chia 7.72 mg. At 30 g, pumpkin, hemp and chia cluster around 2.3–2.5 mg.
Content is not the same as absorption
These figures describe mineral present in the food, not how much the body absorbs. Phytate and other plant compounds can reduce mineral bioavailability. Pairing plant iron with vitamin C can improve non-heme iron absorption.
Phytate helps explain why mineral content and mineral absorption are not identical. Seeds naturally store phosphorus in phytate, which can bind some iron, zinc, calcium, and magnesium. This does not make seeds poor foods; it simply means the number on a composition table is not the same as the amount the body absorbs.
Processing can change availability. Soaking, sprouting, fermenting, grinding, and roasting can alter phytate levels or make minerals easier to access, although the effect varies by seed and method. Tahini, for example, behaves differently from whole sesame because the seed is ground and sometimes hulled.
Calcium in sesame deserves special context. Whole unhulled sesame can contain a large amount, but much of it sits in the hull and bioavailability is limited. Hulled sesame may show less calcium on paper. A high milligram value should therefore not automatically be treated as equivalent to dairy or a fortified drink.
Serving size keeps the numbers realistic. Two tablespoons of seeds can enrich a meal with magnesium, iron, healthy fats, and protein, but they are not normally eaten in 100-gram portions. Using several seed types across meals may be more practical than trying to obtain every mineral from the one that ranks first.
Vitamin C can improve absorption of non-heme iron from plant foods. Adding fruit, peppers, tomatoes, broccoli, or another vitamin-C-rich food to a meal with seeds is a simple way to support iron uptake. Tea and coffee taken with the meal can have the opposite effect for some non-heme iron.
Grinding seeds can make them easier to incorporate into food and may improve access to some nutrients, but ground products expose more surface to oxygen. Keeping ground flax, sesame meal, or seed mixes sealed and cool helps protect flavor and unsaturated fats.
Seeds also bring substantial unsaturated fat and energy, which is nutritionally useful but easy to overlook when focusing only on minerals. A spoonful sprinkled on vegetables, yogurt, soup, or oats can improve nutrient density without requiring a very large portion. That approach makes mineral-rich seeds an addition to a varied diet rather than a concentrated supplement-like dose.
Serving size keeps the ranking useful
Thirty grams of seeds generally provides roughly 150–200 calories. A 5 g sprinkle will not deliver the same mineral amounts as the table, and eating 100 g solely to chase one mineral is rarely necessary.
The winner depends on the nutrient: hemp for magnesium, whole sesame for calcium and iron, with pumpkin and chia providing strong alternatives.
Sources
- USDA FoodData Central — Hemp seed, hulled (FDC 170148) — Hemp magnesium, calcium and iron.
- USDA FoodData Central — Pumpkin seeds, raw (FDC 2515380) — Current Foundation pumpkin-seed minerals.
- USDA FoodData Central — Sesame seeds, whole, dried (FDC 170150) — Whole sesame minerals.
- USDA FoodData Central — Chia seeds, dried (FDC 170554) — Chia minerals.
- USDA FoodData Central — Sunflower seed kernels, raw (FDC 2515381) — Current Foundation sunflower-seed minerals.