Calcium Urine Test

A urine calcium test is done to check for kidney function and presence of kidney stones. It may also be recommended to diagnose certain disorders of the parathyroid glands. Parathyroid glands, present near the thyroid gland located in the neck, help in regulating the amount of calcium within body. Certain symptoms, such as back pain or abdominal pain, presence of blood in urine, increased frequency of urination, muscle cramps, tingling in fingers, dry skin and brittle nails may also warrant a urine calcium test for the evaluation of the underlying condition.

No special preparations are necessary for this test. Some medications may interfere with test results; hence, if a person is on any ongoing medication, it should be brought to the notice of the physician and discontinued before the test only at the discretion of the physician. There are no risks involved in this test.

A 24-hour urine sample is collected for this test. The pathology laboratory will provide a container coated with a preservative for collecting urine over a period of 24 hours. The following steps should be followed:

• The first urine in the morning should be flushed out and not collected. The time should be recorded.
• For the next 24 hours, all urine should be collected in the container provided.
• The container should be stored in a refrigerator or a cooler with ice and should be deposited to the laboratory or the health provider’s office on the next day as instructed.
• In infants, the area around the urethra should be carefully washed before urine collection. A urine collection bag is generally used for infants.
• For male infants, the penis can be placed in the bag, and an adhesive is attached to the skin. The bag is placed over the labia in female infants. A diaper is placed over the bag.
• The infant should be frequently checked for urination.
• It may be difficult to obtain a sample from active babies, and several attempts may be needed, as overactive babies may displace the bag. Urine is drained into the container provided and then transported to the laboratory.

Normal results: A calcium concentration of 100-300 milligrams (mg)/day is considered normal. If a person is on a diet low in calcium, the values should be 50-100 mg/day.

Abnormal results: Increased calcium in urine could be a result of:

• Milk-alkali syndrome
• Idiopathic hypercalciuria
• Hyperparathyroidism
• Renal tubular acidosis
• Vitamin D intoxication
• Renal failure
• Sarcoidosis
• Using loop diuretics

Low levels of urine calcium may be due to

• Malabsorption
• Hypoparathyroidism
• Vitamin D deficiency
• Use of thiazide diuretics

Certain drugs, such as antacids, anticonvulsants, carbonic anhydrase inhibitors and loop diuretics, may increase urine calcium values and should be avoided. Certain drugs, such as adrenocorticosteroids, oral contraceptives and thiazide diuretics, may decrease urine calcium levels.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational perspective and is in no way a substitute for medical advice from a qualified doctor.