Too Much Calcium & the Kidneys

Calcium is an essential mineral involved in several biological processes, including muscle contraction and bone formation. Levels of calcium in the body are regulated primarily by vitamin D and parathyroid hormone. Excessive intake of vitamin D supplements or diseases affecting the parathyroid gland can cause calcium levels to increase in the body, leading to a condition known as hypercalcemia. Many organs in the body are affected by hypercalcemia, especially the kidneys.

Calcification of the Kidneys

When the blood is highly concentrated with calcium, the calcium tends to come out of solution and form calcium deposits, a process known as calcification. These deposits often form inside blood vessels or internal organs, such as the kidneys. Calcification of the kidneys causes damage to the delicate organ tissues and can lead to scarification and hardening of the kidneys.

Kidney Symptoms

Calcification of the kidneys can impair their ability to function properly. Frequently, hypercalcemia results in excess urine production, a condition known as polyuria. Excreting large amounts of urine from the body can dehydrate the body, leading to symptoms of excessive thirst, dry mouth, dark yellow urine and the inability to sweat. Malfunctioning kidneys caused by hypercalcemia may also result in pain in the sides and lower back.

Kidney Stones

When calcium deposits form in the kidneys, they can lead to kidney stones, small mineral crystals that form inside the tubes of the kidneys that are connected to the urinary tract. Kidney stones are extremely painful, both inside the body and as they travel through the urinary tract. When kidney stones are inside the kidneys, they often cause a dull, aching pain around the area of the kidneys, in the side and lower back. When they travel through the body and pass out of the urethra, they can cause excruciating pain.

Additional Symptoms

Hypercalcemia can cause many symptoms affecting other parts of the body in addition to the kidneys. Nausea, vomiting and constipation are early symptoms of hypercalcemia. Muscle twitches and weakness may also develop. Mental status may also be affected, causing depression, irritability, memory loss, apathy and dementia. Hypercalcemia can also cause calcification of the blood vessels, leading to atherosclerosis, and calcification of the heart, leading to heart disease. The bones can also be affected, resulting in curvature of the spine, bowing of the shoulders, bone pain, bone fractures and a decrease in height.

Photo Credits:

  • bones and bones image by JASON WINTER from
