Dark-colored sodas and other similar drinks are not good for those with kidney disease. In general, manufacturers add phosphorus to these products to boost flavor, extend shelf life, and prevent discoloration. The problem is that this form of phosphorus is not bound to protein, but in salt form. As a result, it can be absorbed easily into the blood. While healthy kidneys may get rid of excess phosphorus, it may be a challenge when kidney issues occur. High levels of phosphorus in the blood for a long period may increase the risk of heart disease and lead to weakened bones. Sodas also contain added sugar and sweeteners, which may worsen kidney health. Therefore, it is advisable to go for healthier options, such as sparkling water, plain water, or tea.