Calcium is one of the most important minerals for the normal functioning of the human body. It also happens to be one of the most abundant and has an important role to play in a variety of life functions. Apart from its presence in the bones and teeth, calcium is also present in large quantities in the muscles and nervous system due to its importance in muscle contraction and transmission of nerve impulses. There is a delicate balance between the levels of calcium in the bloodstream, and the quantity present in the bones.
The body balances these levels by causing calcium to enter the blood from the skeletal system, and vice versa, as and when the levels of blood calcium fluctuate to either the higher or lower ends. Excess calcium is either stored by deposition in the bones or is excreted through urine. The levels of calcium in urine allow doctors to understand your body's calcium levels. Urine calcium levels can indicate hypercalcemia & hypocalcemia - important symptoms of several hormonal, metabolic, infectious, and metastatic diseases.
What is Calcium in Urine & Why is it Tested?
- The presence of calcium in urine is known as calciuria. The amount of calcium in urine can be tested and the numbers can indicate either the excess or lack of calcium in your body.
- Urine calcium levels are often estimated when your doctor suspects conditions like:
- Kidney stones
- Vitamin D toxicity
- Breast cancer
- Urine calcium levels are also tested to ascertain calcium intake and to ensure there is no malabsorption of calcium from the small intestine.
- Since calcium estimations are not commonly a part of the yearly physical exams, your doctor orders them from the lab specifically to detect certain conditions they might suspect.
What Factors Affect Bodily & Urine Calcium Levels?
- Since the role of calcium is so widespread in living tissues, calcium levels in the body are very dynamic.
- The parathyroid hormone is released the moment calcium levels drop in the bloodstream, making bones release calcium into the blood.
- On the other hand, when there is sufficient circulating calcium in the body, the release of the parathyroid hormone is suppressed.
- Another hormone - calcitonin, which is secreted by the thyroid gland, is responsible for the deposition of calcium in the bones by lowering calcium concentration in the blood.
- Since the kidneys filter the blood for impurities, wastes, and excess minerals, blood calcium levels have a direct impact on the amount of calcium in urine.
- Other hormones such as estrogen also have an important role to play in the body’s calcium metabolism.
- Vitamin D, an important micronutrient, greatly influences the body’s rate of calcium absorption.
- Individual diets also have an impact on urine calcium levels, with individuals on a diet with greater calcium concentration showing higher levels of calcium in urine.
Normal Urine Calcium Levels
- For people that live on a high-calcium diet, normal urine calcium levels are between 100 and 300 milligrams a day.
- On the other hand, for individuals that consume a diet poor in calcium, the urine calcium levels tend to be between 50 and 150 milligrams a day.
- A fluctuation in these levels to the higher side is called hypercalciuria, which can be an indication of hypercalcemia. Conversely, a urine calcium level that is too low is called hypocalciuria and can indicate hypocalcemia.
- In case you’re wondering what is considered a high level of calcium in urine - above 250 milligrams of calcium per day in women, and over 300 milligrams of calcium in urine per day in men, is termed hypercalcemia.
- Levels below 50 milligrams indicate a low level of calcium in urine.
Hypercalciuria & Hypercalcemia
- While hypercalciuria is an abnormally high concentration of calcium in urine, hypercalcemia is an excessively high level of calcium in the blood. The former is often the result of the latter.
- Hypercalcemia is a symptom of several underlying diseases and disorders. While calcium is essential for day-to-day functions of the body, abnormally high levels can point to serious conditions, and when left unchecked, can even be life-threatening.
- So, what does high calcium in urine indicate? Hypercalciuria and hypercalcemia have several implications, which include conditions such as:
- Hyperparathyroidism: This condition is caused by an overactive parathyroid gland or the enlargement of the glands due to the presence of a tumor.
- Sarcoidosis: This disease is characterized by the collection of inflammatory cells in different parts of the body like the lungs, eyes, lymph nodes, and skin.
- Tuberculosis: This infectious disease can increase the amount of vitamin D in the affected individual’s blood, leading to hypercalcemia and subsequently, hypercalciuria.
- Genetic conditions: A rare disease called hypocalciuric hypercalcemia is characterized by the rise in blood calcium levels, but a decrease in the amount of calcium excreted through urine.
- Cancer: Metastatic conditions, especially breast cancer, are known to increase the concentration of calcium in the blood, and subsequently increase the calcium levels in urine.
- Medications & Side-effects: Prolonged usage of drugs like loop diuretics that cause water loss to treat heart failure & nephrotic syndrome, and lithium which is used to treat conditions such as bipolar disorder, schizophrenia, and psychosis, can all lead to hypercalcemia and hypercalciuria.
- Vitamin D toxicosis: An excessive intake of supplements causes vitamin D toxicosis. This can raise calcium levels in the serum, and calcium in urine.
- Lifestyle: Individuals with sedentary lifestyles are more prone to have increased calcium levels in urine and serum.
Symptoms of Hypercalcemia & Hypercalciuria
- While calcium in urine entails little to no symptoms, hypercalcemia, on the other hand, has a number of notable symptoms. These symptoms span various organ systems, and include:
- Frequent urination & increased thirst
- In case hypercalcemia results in kidney stones, it can cause pain in the upper abdomen and lower back.
- Hypercalcemia can result in either hypercalcemic diarrhea or constipation
- Nausea & vomiting
- Abdominal cramps and discomfort
- Muscle twitches & tremors
- Memory loss
- Mood swings & irritability
- Bone pain
- An increased risk of fractures
Hypocalciuria & Hypocalcemia
- Hypocalciuria indicates reduced concentrations of calcium in urine, and hints at underlying hypocalcemia.
- Hypocalcemia is also a symptom for several underlying conditions ranging from endocrine disorders to digestive tract anomalies.
- Low calcium in urine and hypocalcemia can be due to the following reasons:
- Malabsorption: Impaired absorption of nutrients into the bloodstream from the small intestine can cause a decrease in the levels of calcium. This can also be precipitated by incessant diarrhea or vomiting due to infections or other disorders.
- Hypoparathyroidism: This results due to a decrease in the activity of the parathyroid glands which regulate the levels of calcium and phosphates in the blood by monitoring their release from the skeletal system.
- Vitamin D deficiency: A diet deficient in vitamin D, or leading an inactive lifestyle can lead to a reduction in bodily vitamin D reserves. This can cause malabsorption of calcium, leading to hypocalcemia, and eventually reduced urine calcium levels.
- Drug side effects: Certain drugs reduce the excretion of calcium in urine, which can lead to hypocalciuria. Thiazide diuretics are examples of drugs that inhibit calcium excretion through urine.
Diagnosis & Testing for Urine Calcium Levels
- Your doctor might order a calcium urine test to help them arrive at a diagnosis.
- Calcium urine testing is a routine procedure when testing for hyper or hypocalcemia, and is a rather straightforward procedure that takes about a day’s worth of sample collection.
- Be sure to give your doctor a complete and detailed medical history, as they might ask you to stop taking some of them in case they think the drugs might affect the test results.
- Your doctor might also try and ascertain the levels of calcium in your diet and might even suggest a specific diet to follow in the days leading up to the test.
- The procedure of the test is carried out over a day and can be explained as below:
- On the morning of the first day, urinate as usual and do not collect the sample.
- Collect a sample every time you urinate for the subsequent 24 hours after the day’s first urination.
- On the morning of the second day, collect a sample from the day’s first urine.
- Keep the collected samples refrigerated.
- Hand the samples over to the lab assistants in sealed containers.
Treating High & Low Calcium in Urine
- In case you have been thinking about how to lower calcium in urine, or about how to increase the levels of calcium in your dietary intake, the solutions exist in the underlying causes.
- Since both hypocalciuria and hypercalciuria are symptoms, your doctors will create a treatment plan based on the final diagnosis and cause of your condition.
- Speak to your healthcare provider to understand your condition and the range of options you have to address the problem.
Urine is not only an excretory product, but it also contains markers for several bodily parameters. Other elements such as sugar in urine can point toward conditions such as diabetes. While calcium in urine is an important indicator of health and the level of this quintessential mineral, aberrations in these levels can indicate serious issues. It’s important not to ignore any symptoms mentioned above, and to watch out for healthy dietary options that provide you with the optimal calcium content.