How can excessive sodium intake affect overall health?

Excessive sodium intake is closely linked to hypertension, or high blood pressure, which is a significant risk factor for cardiovascular diseases. When the body consumes too much sodium, it retains more water to balance the sodium levels, leading to increased blood volume. This additional volume exerts extra pressure on the walls of blood vessels, contributing to hypertension. Over time, high blood pressure can lead to various cardiovascular issues, including heart attack and stroke.

While the other options mention effects that may seem plausible, they do not align with the well-established consequences of high sodium intake. For instance, sodium does not improve heart health; rather, it's associated with risks. Bone density isn't directly decreased by sodium but can be affected by various dietary factors. Kidney function is typically stressed by high sodium levels, not enhanced, as the kidneys must work harder to excrete the excess. Thus, the positive association with cardiovascular disease is a critical factor to understand regarding sodium consumption.