Calcium and Kidney Disease


Calcium is the most abundant mineral in the body and is well-known for its role in bone health. We need calcium to build strong bones and lower the risks of osteoporosis and bone fractures. The majority of calcium in the body is located in the bones, and a very small percentage circulates through the blood.

Patients with kidney disease may have either too much or too little calcium. End-stage kidney disease sometimes leads to hypercalcemia, which is too much calcium in the blood. When calcium deposits travel in the bloodstream, it can cause heart complications and other problems. However, hypocalcemia (low levels of circulating calcium) is also a risk for patients with kidney disease due to the relationship between calcium and phosphorus. The relationship between calcium and kidney disease is complicated, which is why it’s important to get your blood calcium levels tested.

If you have kidney disease, you should monitor your consumption of calcium-rich foods such as dairy and spinach. Many foods are also enriched with calcium, so you need to look out for those labels. Dairy-free alternatives, such as soy milk, that are naturally lower in calcium are usually fortified with calcium. The National Kidney Foundation suggests that people with kidney disease should not have more than 2000mg of calcium each day. Check with your physician whether you need to lower or increase your calcium levels.

Many calcium-rich foods are also high in phosphorus, which should be avoided if you have kidney disease. If you have low calcium levels, be sure to take calcium supplements or choose foods that are high in calcium but low in phosphorus. Phosphorus binds to calcium in the blood, meaning that less calcium will be freely available. Some doctors may prescribe a phosphorus binder, which will bind to phosphorus, thus preventing it from binding to calcium. The less phosphorus you consume, the more circulating calcium you will have. We hope this article helped you understand rules of calcium intake for CKD patients.