Cashews are the highest-iron nut you’ll find in most grocery stores, delivering about 8.2 mg of iron per cup (dry roasted). That’s already more than a full day’s worth for adult men, who need 8 mg daily. Other strong performers include pine nuts, hazelnuts, almonds, and peanuts, though none come close to cashews on a per-serving basis.
Iron Content of Common Nuts
Not all nuts pull their weight when it comes to iron. Here’s how the most popular options compare, ranked from highest to lowest per standard serving:
- Cashews (dry roasted): 8.2 mg per cup, or roughly 1.9 mg per ounce
- Hazelnuts: 5.4 mg per cup chopped, or about 1.3 mg per ounce
- Almonds (dry roasted): 5.2 mg per cup, or 1.1 mg per ounce (about 22 kernels)
- Peanuts (dry roasted): 2.3 mg per cup, or about 0.6 mg per ounce
- Black walnuts (dried): 0.9 mg per ounce
- English walnuts: 0.8 mg per ounce (about 14 halves)
A realistic snack portion is about one ounce, so you’re likely getting between 0.8 and 1.9 mg of iron from a handful of nuts depending on which you choose. That might not sound like much on its own, but it adds up across a full day of eating. Cashews stand out because even a single ounce covers about 11% of the daily value.
Cashews also bring copper and folate to the table, both of which support healthy red blood cell production. A cup of dry roasted cashews contains about 3 mg of copper and 95 micrograms of folate, making them unusually well-rounded for blood health among plant foods.
How Much Iron You Actually Need
The recommended daily amount depends heavily on age and sex. Adult men and anyone over 51 need 8 mg per day. Pre-menopausal women need 18 mg, more than double that, because of monthly blood loss. If you eat a fully vegetarian or vegan diet, multiply those numbers by 1.8. That puts vegetarian women of reproductive age at roughly 32 mg per day, a target that’s genuinely difficult to hit from food alone.
The reason vegetarians need so much more comes down to the type of iron in plant foods. Nuts contain only non-heme iron, which your body absorbs less efficiently than the heme iron found in meat. This doesn’t make nuts a poor iron source, but it does mean you need to be strategic about how you eat them.
Nuts Contain Their Own Absorption Blockers
Here’s the catch with nuts and iron: they contain natural compounds called phytates and polyphenols that actively interfere with iron absorption. In one study, meals that included walnuts, almonds, peanuts, or hazelnuts alongside bread resulted in iron absorption of just 1.8%, compared to 6.6% from bread eaten alone. That’s a nearly fourfold reduction.
Coconut was the exception. It contains significantly lower levels of both phytates and polyphenols, and it didn’t reduce iron absorption in the same way. So while dried coconut is lower in total iron content (about 0.9 mg per ounce), more of that iron may actually reach your bloodstream compared to what you’d absorb from almonds or walnuts.
This doesn’t mean you should avoid iron-rich nuts. It means the number on a nutrition label overstates what your body will actually use, and pairing matters.
Pairing Nuts With Vitamin C
Vitamin C is the most effective natural enhancer of non-heme iron absorption. It binds with iron in your gut and converts it into a form your intestines can take up more easily. One study found that consuming 100 mg of vitamin C in the same meal increased iron absorption by 67%.
In practical terms, 100 mg of vitamin C is about one medium orange, a cup of strawberries, or half a red bell pepper. Some easy pairings:
- Cashews or almonds with orange segments as an afternoon snack
- Chopped hazelnuts over a spinach salad dressed with lemon juice
- Peanut butter on toast with sliced strawberries
- Trail mix with dried mango or pineapple (both high in vitamin C)
The key is eating the vitamin C source and the nuts at the same meal or snack, not hours apart. Iron absorption happens in the upper part of your small intestine, so both nutrients need to arrive there together.
How Seeds Compare to Nuts
If you’re open to seeds as well as nuts, they tend to outperform nuts on iron content. Pumpkin seed kernels (also called pepitas) deliver 9.5 mg per cup when roasted, surpassing even cashews. Sesame seeds are another standout at about 4 mg per ounce in their flour form. Seeds are subject to the same phytate absorption issues as nuts, so vitamin C pairing still applies.
A trail mix combining cashews, pumpkin seeds, and dried fruit high in vitamin C gives you the best of both worlds: a concentrated plant-based iron source with a built-in absorption booster. For people actively trying to raise their iron intake through snacking, this kind of deliberate combination is far more effective than eating any single nut on its own.