Spinach stays always high in the list of plant-based products, rich in calcium, as it has the most calcium in this category (260mg/cup cooked). However, it’s not only about what products contain the highest amounts of calcium, but also about whether your body can use calcium from them. In the case of spinach, its high amounts of oxalates lower the bioavailability of calcium so that only 5% (about 13 mg) of calcium can be used by the body! To compare, calcium absorption from from dairy and soy products is about 32%. This means that you would need to eat 16 servings of spinach (85 gr) to obtain as much calcium as from a glass of milk! As you can see, it is not wise to rely on spinach as a significant source of calcium since most of it will not be absorbed by the body.
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