New Era No. 2 Calc Phos contains calcium phosphate as its single tissue salt, with biotin in a lactose base. In tissue salt use, calc phos is traditionally linked with growth, repair and rebuilding. It is the mineral most often chosen when support is aimed at bones, teeth, recovery after illness, or that generally run-down state that can follow stress or poor appetite.
Because this is a single-salt product, it is more specific than the lettered combinations. If you are buying New Era No. 2 Calc Phos, you are usually buying specifically for calc phos rather than for a mixed symptom picture. Biotin is the added nutrient and contributes to normal energy metabolism.
Calc phos is also one of the tissue salts often discussed alongside vitamin C and calcium-containing foods because of its association with normal bone and tooth structure. In tissue salt practice, that is one reason it is commonly chosen during growth phases and recovery periods.