As I deal with the issues of PMR and taking and tapering Prednisone, I am monitoring my calcium and sodium. I visit a local discount grocery that gets unsold items near their shelf date and sells for 25 to 50% of the regular retail price. They usually have a lot of expensive yogurt brands that comes from the Whole Foods and other high-end groceries. I've discovered several cultured mild products there, including the skyr you mention, essentially another form of kefir, a drinkable yogurt.