We use Hemp and Rice milk at our house. Not sure if this is the case with all Hemp Milk, but ours is not high in calcium (we use the Manitoba Harvest brand and it only has 2% of the RDI of calcium). It was my understanding that Hemp Milk is high in iron and therefore even if you buy a brand fortified with calcium the body wouldn't absorb it so well. But as a fat and protien source it is great.