Why is it impossible to obtain enough calcium from plant sources?

Calcium from plant sources has lower bioavailability compared to calcium from dairy products. This is due to the presence of anti-nutrients such as:

• phytates (found in sesame, nuts, legumes) — they bind minerals, including calcium, and inhibit their absorption in the intestine;

• oxalates (in spinach, rhubarb, sorrel) — also interfere with calcium absorption.

In the case of sesame: despite the very high calcium content (over 900 mg per 100 g), only a small portion is absorbed — about 10–20%, or even less if the sesame has not been pre-processed (soaking, roasting, fermentation).

To enhance calcium absorption from plant sources, it is beneficial to:

• combine them with vitamin D and magnesium;

• minimize anti-nutrients (through soaking, sprouting, fermentation).

Thus, sesame is not the best source of calcium in terms of absorbability, despite its high content.