Limestone flour is a pure calcium supplement given to various animals to increase their calcium intake. 
Tortoises have a very high calcium to phosphorus ratio in their natural diets so a pure calcium supplement makes sure their intake needs are met. Calcium Carbonate is found in rocks and sediments all over the world. Its produced by mining minerals rich in Calcium Carbonate then purified, dried and the end product is then milled to a fine flour.
This can be added to foods several times a week, a small pinch is sufficient for most individuals with a good varied diet.
Suitable for all species.