NPR’s The Salt reports that Navajo people, like most North American Indians, are lactose intolerant. That means that milk is of no use to them as a source of calcium. But they do like a bit of juniper ash sprinkled in the corn mush. And a gram of that ash contains about as much calcium as a glass of milk. Furthermore, the calcium in juniper ash is claimed to be more bio-available than the calcium in milk.
What we aren’t told is whether juniper has more calcium in its ash than other local plants.