Final answer:
Calcium-phosphorus precipitation is increased by an imbalance in the calcium to phosphorus ratio, elevated serum phosphate levels, addition of calcium compounds that alter pH, and the presence of other ions like iron. The common ion effect also plays a role in reducing the solubility of calcium phosphate.
Step-by-step explanation:
Factors that increase calcium-phosphorus precipitation include an imbalance in the optimal ratio of calcium to phosphorus, which is approximately 1:1. When the concentration of serum phosphate increases, it can cause a reciprocal decrease in serum calcium concentration, also facilitating precipitation. Furthermore, adding compounds like calcium hydroxide can increase the pH and prompt the reaction of calcium ions with phosphate ions to form insoluble compounds such as hydroxylapatite. Additionally, the presence of other ions like iron can disrupt the absorption and balance of calcium and phosphorus due to the formation of insoluble ferric phosphate. The addition of soluble calcium salts to a saturated calcium phosphate solution can further causes calcium phosphate precipitation due to the common ion effect, which reduces solubility.