Dark, leafy greens, like broccoli and kale, are calcium rich foods to offer your birds.
Cuttlebone (which comes from a type of squid) and mineral blocks offer a stable form of calcium, calcium carbonate, to pet birds. You can attach these items to cage bars for easy access. The soft side of the cuttlebone should be facing the bird, not the hard portion, which they might not be able to scrape through. These items also often contain trace minerals vital to a bird’s daily bodily functions:
Iron — for red blood cell formation and function, carrying oxygen in the bloodstream and egg production.
Manganese — to properly metabolize fats and sugars and improve egg hatchability
Potassium — maintains normal heart and muscle activity
Zinc — immune system
Copper — for proper circulation and healing
Magnesium — activates enzymes
Phosphorus — for calcium metabolism
Sodium — for almost every bodily function
Even if your bird has access to a cuttlebone, it will still need to absorb calcium from foods, such as leafy greens, because these natural sources are more readily digestible.