Worried About Bone Meal for Home Prepared Diet? Try Natural Calcium Harvested from the Sea This calcium is a natural seaweed product harvested from the seabed off the southwest coast of Ireland. Here amongst the cleanest and purest waters found anywhere is the world, grows the small red seaweed Lithothamnium which is composed of a wide variety of body essential nutrients, including calcium, phosphorus, magnesium, boran, and zinc. IMPORTANT INFORMATION: Manufacturer: Merritt Naturals Type: Powder Size: 12 oz.