Hypercalciuria

Hypercalciuria could occur on its own, even with normal blood calcium levels. Or it could be a side effect of another condition that causes high calcium levels.

Excess calcium in the urine can occur even when blood tests show normal calcium levels. Idiopathic hypercalciuria (idiopathic indicates no known reason) is seen in 3-6% of children. It is possible for idiopathic hypercalciuria to occur at any age, but it is seen most commonly between the ages of four and eight years.

In many cases, it may be difficult to pinpoint a specific cause. There could be many possible reasons for developing hypercalciuria. These include:

• Diet rich in proteins
• Diet high in sodium
• Not consuming enough water and fluids (Read more: Dehydration, causes, symptoms)
• A family history of kidney stones
• Certain medication, including corticosteroids and vitamin D supplements
• Certain underlying conditions such as hyperparathyroidism, renal phosphate leak, sarcoidosis or milk-alkali syndrome (a condition in which excess dietary calcium changes the acid/base balance of the body and could damage the kidneys).
• Rarely, increased absorption of calcium in the intestines could be the cause.

The following symptoms and conditions may be associated with hypercalciuria:

• Blood in urine
• Kidney stones
• Abdominal pain
• Burning sensation while urinating
• An urgency to go pee, and bedwetting in children
• Urinary tract infections (UTIs)
• Osteoporosis or weakening of bones due to a problem with bone resorption in the body

You should consult a medical practitioner as soon as you notice the above-mentioned symptoms. The doctor is likely to ask you questions about the severity of your symptoms and might prescribe the following tests for better diagnosis:

• Urine test to check for calcium and other minerals. (Read more: Calcium urine test)
• Renal ultrasound and other imaging tests that don’t deliver radiation to check for stones and other possible abnormalities
• A blood test may also be ordered to understand the cause of hypercalciuria.
• The doctor may also prescribe genetic testing in some cases, especially if there’s a family history of kidney stones. (Read more: DNA testing)

Experts say the normal amount of calcium in urine can be measured in a few different ways. Some of them are listed here:

In adults

• More than 275 mg of calcium in urine in men and over 250 mg of calcium in urine in women in a day is considered high.
• Some experts feel that the above doesn't take into account high-normal calcium in the urine and other important factors. They suggest that while anything less than 200 mg calcium per litre of urine excreted over 24 hours is normal, less than 125 mg of urinary calcium concentration is "optimal".

In children

• Daily excretion of more than 4 mg per kilogram body weight of calcium through urine can be used to diagnose hypercalciuria in children over two years of age
• In children over two years old of age, the ratio of urinary calcium to creatinine should be under 0.2 mg calcium/creatinine mg. Though, less than 0.18 mg calcium/creatinine mg is considered optimal.
• In infants, the urinary calcium to creatinine levels by age should be:
  • Under 0.8 for children up to six months
  • Under 0.6 for children aged six months to a year

The treatment plan for hypercalciuria depends on the cause. If an underlying disease is found during the course of the diagnosis, then treating it will also improve hypercalciuria.

A change in dietary habits may also go a long way in treating hypercalciuria. A dietician could be consulted for the same, especially in the case of children. Sodium consumption should be reduced and fluid intake should be increased to reduce calcium levels in urine.

To prevent the formation of kidney stones (mainly calcium oxalate stones), the doctor may prescribe medicines if dietary changes are not enough.