Additiva calcium is a calcium preparation in an easy to drink effervescent form which boosts your bones health. Additiva Effervescent calcium tablets may be used as treatment with or without other therapy to stop or slow down the breakdown of minerals in the bones of those with osteoporosis (Brittle Bones) where other effective treatment cannot be used. Additiva Effervescent calcium tablets may also be used as a calcium supplement if you have bone softening due to vitamin D deficiency (Osteomalacia).