You don't have to that at all, of course. First of all, nobody really knows how much calcium you really need per day, all those estimates are ballpark estimates at best.

The estimates of 1000mg or more have been pushed for decades by the dairy industry.

You can get calcium from greens like kale etc. eat a bit of brocolli, eat pulses like beans and lentils, use tahini as a sauce, drink fortified plant-milk.

Just eat a well-balanced plant-based diet and you will be absolutely fine. Studies show that plant-based diets don't cause brittle bones at all on the contrary.

You can get all the nutrients that you need, calcium included from a plant-based diet. The only thing you need to supplement is B12, which is produced by bacterias in the dust.

And as everything is so clean, we don't eat a lot of dirt anymore so that its advised to supplement. Animals don't have it too on factory farms, they get injected with it together with the anti-biotics for health reasons.

So might as well take it directly, otherwise calcium is not an issue at all in a plant-based diet and this can and it has been easily shown.

Edit: Check this YouTube playlist on bone health for more info - https://www.youtube.com/playlist?list=PL5TLzNi5fYd_ACcY8TDQC...