Calcium is a vital electrolyte and mineral that plays a crucial role in the overall functioning of the body. Although it is best known for its role in maintaining strong bones and teeth, its functions go well beyond that.

Calcium is involved in:

• Muscle contractions.
• Nerve function.
• Blood coagulation.
• The release of certain hormones.
• The regulation of other minerals such as phosphorus and magnesium.

A calcium test is often included in metabolic panels but may also be requested individually in case of specific symptoms or conditions.

Indications for a Calcium Test:

• Nervous system problems : Muscle cramps, tingling, or abnormal reflexes.
• Bone health problems : Signs of osteoporosis, pathological fractures, or weakened bones.
• Kidney disorders : Monitoring of kidney function or detection of kidney stones.
• Recurrent muscle spasms or seizures : A sign of a calcium imbalance affecting muscle function.
• Chronic diseases : Monitoring of parathyroid gland disorders or other chronic conditions.
• Suspected vitamin D deficiency : Since calcium and vitamin D are closely linked, a deficiency may require evaluation.

The calcium test is usually done by a blood test, via a venous sample.

Common Test Methods:

• Complete Metabolic Panel (CMP) : Evaluates electrolyte and mineral balance.
• Basic Metabolic Panel (BMP) : Provides a general overview of metabolic health, including calcium.
• Serum Calcium Test : Specifically analyzes calcium levels in the blood.

Other tests:

• Ionized Calcium Test : Measures free calcium in the blood, offering more accurate information in case of abnormal total levels.
• Urine Calcium Test : Measures the amount of calcium excreted in the urine over 24 hours, useful for detecting metabolic or kidney problems.

Test preparation:

• On an empty stomach : It is often recommended to fast for 8 to 12 hours before the test to get accurate results.
• Hydration : Drinking water is encouraged to facilitate blood sampling.
• Medications : Some medications can affect calcium levels. Tell your doctor about your current treatments.

The reference ranges vary according to age:

Blood calcium (mg/dL)

• Children (under 17) : 8.8—10.8
• Adults (18—59 years) : 9.0—10.0

Urinary calcium (mg/day)

• Normal Calcium Diet : 100—300
• Low Calcium Diet : 50—150

note : The units of measurement and the normal ranges may vary between laboratories.

High levels (Hypercalcemia)

High calcium levels may indicate:

• Hyperparathyroidism : An overproduction of parathyroid hormone.
• Vitamin D toxicity : Excessive absorption of calcium due to excess vitamin D.
• Kidney problems : Impaired kidney function that reduces calcium excretion.
• Cancers : Some cancers, especially bone cancers, can release calcium into the blood.
• Prolonged immobility : The release of calcium from bones during prolonged inactivity.
• Milk-alkaline syndrome : Excessive consumption of supplements rich in calcium.

Recommendations:

• Consult a doctor for additional tests (e.g. parathyroid hormone).
• Maintain a balanced diet without excess calcium.
• Drink plenty of water to help the kidneys eliminate excess calcium.

Low levels (Hypocalcemia)

Low levels may indicate:

• Vitamin D deficiency : Affects calcium absorption.
• Low proteins : Reduction of calcium bound to proteins.
• Parathyroid dysfunction : Hormonal failure affecting calcium.
• Pancreatitis : Deposition of calcium in inflamed tissue.
• Digestive disorders : Diseases such as celiac disease.

Recommendations:

• Increase your calcium intake through rich foods (green leafy vegetables, dairy products).
• Ensure a good supply of vitamin D through diet, supplements, or sun exposure.
• Consult a professional to monitor other electrolytes such as magnesium.

In case of abnormal calcium levels, consult:

• Endocrinologist : Specialist in hormonal disorders, including those of the parathyroid glands.
• Nephrologist : Specialist in kidney diseases if a link with kidney function is suspected.
• General practitioner : For initial assessment and recommendations.

Managing calcium levels quickly and appropriately can prevent complications and improve quality of life.