Comparisons › Kale vs spinach
Kale vs spinach
For calcium and iron, kale wins in practice. Both greens contain these minerals, but spinach is high in oxalates that bind much of its calcium and iron, so you absorb relatively little. Kale is low in oxalates, so more of what it offers actually reaches you.
See what your diet might be missing. Free, in 60 seconds →Cooked kale vs Cooked spinach, per serving
| Nutrient | Cooked kale per 1 cup cooked (130g) | Cooked spinach per 1 cup cooked (180g) |
|---|---|---|
| Iron | 1.09mg | 6.43mg |
| Calcium | 195mg | 245mg |
Per-serving figures from the Plentish dataset. The two servings differ, so read the amounts in context.
The oxalate difference
Spinach is nutritious and rich in folate and vitamin C, but it is not the iron or calcium powerhouse it is often billed as, because oxalates lock much of those minerals away. Kale, pak choi and broccoli are lower in oxalates and more reliable mineral sources on a dairy-free diet.
Common questions
Is kale better than spinach?
For calcium and iron, yes, because spinach’s oxalates limit absorption. Both are healthy greens; kale, pak choi and broccoli are the more reliable mineral sources.
Is the iron in spinach usable?
Only partly. Oxalates bind much of spinach’s iron, so you absorb relatively little. Pair any greens with vitamin C to help.