Hypocalciuria is a medical condition that results from low levels of calcium in urine. The kidneys naturally hold a certain amount of calcium, but when calcium levels rise beyond the kidneys’ capacity, the excess calcium is secreted in the urine. Patients with hypocalciuria have very little or no calcium present in their urine samples. Testing for calcium in the urine is helpful because it can be an indicator of certain medical conditions, including preeclampsia, vitamin D deficiencies, malnutrition, and parathyroid problems.
In most cases, hypocalciuria does not present symptoms on its own, and calcium levels often fluctuate from day to day. A urine calcium test is not a routine procedure. Physicians reserve the test as a noninvasive way to screen a patient who has symptoms of other problems that could cause hypocalciuria.
Testing for calcium in the urine is a risk-free way to evaluate calcium levels, though diagnosis of certain conditions often requires a blood calcium test as well. Urine tests require patients to collect all urine voided for a 24-hour period, which is usually accomplished at home. Patients return urine collected over the entire period in a large sterile container for laboratory analysis.
Some patients with hypocalciuria do not have an underlying medical condition. They may simply be lacking calcium in their diets. Certain drugs, such as adrenocorticosteroids, birth control pills, and thiazide diuretics can also cause lower than normal calcium levels in urine. Some physicians ask patients to abstain from taking certain drugs or supplements for several days before taking a urine calcium test.
Correcting or treating hypocalciuria depends on the reason for the low calcium levels. Doctors often perform follow-up blood tests to confirm diagnosis of certain conditions if the results of the urine test indicate low calcium. For example, if a physician suspects low calcium levels may be due to parathyroid problems, he may order a blood test to check.
People who have hypocalciuria due to not meeting their dietary calcium needs can usually correct the problem by adding calcium-fortified foods or beverages to their diets or by taking a daily calcium supplement. If low calcium levels are attributed to malnutrition, physicians usually look for an underlying cause, such as celiac disease or alcoholism, which can be treated with dietary and lifestyle changes or medications. Pregnant women who have hypocalciuria due to preeclampsia are typically given medications to help control their symptoms and are put on bed rest until the baby can be safely delivered to minimize potential risks to the mother and fetus.
