Hypocalcemia

Hypocalcemia may be caused by a combination of environmental, lifestyle, or genetic factors. Key risk factors include:

• Vitamin D Deficiency
• PTH Deficiency
• Hypomagnesemia
• Hypoalbuminemia
• Hyperphosphatemia
• Newborns of Diabetic Mothers
• Family History of Parathyroid Disorders

Less common risk factors include:

• Surgical Removal of Parathyroid Glands
• Medications
• Anion Chelation (Binding of Negative Ions)
• Pseudohypoparathyroidism
• Liver Disease
• Acute Pancreatitis
• Increased Protein Binding
• Critical Illness
• Severe Sepsis
• Gastrointestinal Disorders
• Tumor Lysis Syndrome (TLS): Occurs when large numbers of cancer cells die rapidly, releasing their contents into the bloodstream.
• Osteoblastic Metastases: Certain cancers, like breast, prostate, and lung cancer, can cause hypocalcemia by stimulating the deposition of new bone.
• Anxiety Disorders

If the cause of hypocalcemia is not immediately clear, the most important diagnostic step is to measure serum parathyroid hormone levels. A biochemical profile, alongside PTH testing and a thorough clinical history, can usually pinpoint the cause of hypocalcemia. Additional tests include:

Laboratory Tests

Calcium:

• Hypocalcemia is diagnosed when total serum calcium falls below 8.8 mg/dL (2.2 mmol/L). However, since low plasma protein levels can reduce total serum calcium but not ionized calcium, ionized calcium should be calculated based on albumin levels.

Parathyroid Hormone (PTH):

• In hypocalcemia, PTH levels are typically high if the glands are responding to low calcium or low if the parathyroids are the problem. High PTH with normal kidney function suggests Vitamin D deficiency or calcium malabsorption.

Alkaline Phosphatase:

• Elevated levels of alkaline phosphatase can indicate osteomalacia from Vitamin D deficiency. Serum phosphate levels will be low in non-parathyroid diseases but high in PTH deficiency.

Vitamin D:

• Vitamin D levels help confirm deficiencies, particularly in cases where symptoms are atypical. It is also useful for diagnosing pseudohypoparathyroidism.

Magnesium:

• Magnesium levels help assess parathyroid function. In hypomagnesemia, PTH release is impaired, which can cause severe hypocalcemia. Magnesium must be corrected before calcium levels can improve.

Phosphate:

• Low serum phosphate levels indicate Vitamin D deficiency, calcium loss in urine, or calcium deposition in bones. High phosphate levels with hypocalcemia are seen in chronic kidney failure and hypoparathyroidism.

Imaging

Imaging tests may include:

• Plain Radiography: Can detect bone abnormalities like rickets or osteomalacia and show the spread of certain cancers to the bones.
• Computed Tomography (CT): CT scans of the head may reveal basal ganglia calcification.
• Echocardiogram (ECG): ECG changes associated with hypocalcemia can help determine its severity.

The primary cause of hypocalcemia is a deficiency in calcium and Vitamin D. Preventive measures include:

• Consuming foods rich in calcium, such as dairy products.
• Opting for low-fat or fat-free options to reduce the risk of heart disease.
• Ensuring daily calcium intake as follows:
• 2,000 mg per day for individuals over 51 years old.
• 2,500 mg per day for adults aged 19 to 50 years.
• Including multivitamin supplements in your diet.
• Consulting a healthcare provider to assess Vitamin D requirements.
• Increasing calcium intake by incorporating Vitamin D-rich foods like:
• Fatty fish, such as salmon and tuna.
• Fortified orange juice and milk.
• Mushrooms and eggs.
• Getting sufficient sunlight exposure to boost Vitamin D production.
• Adopting healthy lifestyle changes like:
• Maintaining a healthy weight.
• Exercising regularly.
• Limiting alcohol consumption.
• Avoiding tobacco use.

Specialists to Consult

Hypocalcemia is primarily caused by dysfunction of the parathyroid glands and Vitamin D deficiency. Symptoms can range from mild to severe, and the following specialists may help:

• General physicians
• Endocrinologists, who treat hormonal and metabolic disorders.
• Nephrologists, who focus on kidney-related diseases.

Hypocalcemia management can be categorized into acute and chronic approaches:

Acute Management: Severe hypocalcemia may require hospitalization. The treatment includes:

• Intravenous calcium if serum calcium levels drop below 1.9 mmol/L, ionized calcium falls below 1 mmol/L, or if symptoms are present.
• Oral calcium supplements and calcitriol (0.25 to 1 μg/day) as needed.
• Correction of magnesium deficiency or alkalosis.

Chronic Management: Hypocalcemia that develops gradually is often asymptomatic, but common signs may include paresthesia (tingling sensation), muscle spasms, cramps, and seizures. Treatment includes:

• Calcium carbonate and calcium citrate supplements, which are rich in elemental calcium (40% and 28%, respectively) and well-absorbed.
• The typical dosage for calcium supplements is 1 to 2 grams of elemental calcium, taken three times daily.
• Starting with 500 mg to 1,000 mg of elemental calcium three times daily, with adjustments based on patient response.
• Electrocardiogram (ECG) changes typically improve with calcium and calcitriol supplementation.
• Magnesium supplements are used to address hypocalcemia linked to hypomagnesemia.
• Thiazide diuretics reduce urinary calcium loss by enhancing calcium reabsorption in the kidneys.
• Combining diuretics with a low-salt, low-phosphate diet and phosphate binders is helpful.
• Monitoring serum calcium, phosphorus, and creatinine levels is essential during therapy, with periodic assessments once stabilized.

Correcting Vitamin D Deficiency: If Vitamin D malabsorption is the cause, treatment should address the underlying issue (e.g., a gluten-free diet for patients with celiac disease). Options include:

• Correcting Vitamin D deficiency with ergocalciferol (Vitamin D2) or cholecalciferol (Vitamin D3).
• Ergocalciferol can be administered at 50,000 IU weekly or biweekly, with follow-up evaluations three months later to adjust doses.
• Alternatively, 300,000 IU of ergocalciferol can be given intramuscularly, with the first two injections spaced three months apart and then every six months.
• Vitamin D3 (100,000 IU) can be administered every three months for effective maintenance.
• Vitamin D analogs like calcitriol or alfacalcidol may also be utilized.

PTH Replacement for Hypoparathyroidism: Parathyroid hormone (PTH) replacement therapy can be considered. It helps correct hypercalciuria (low urinary calcium levels), reducing the risk of nephrocalcinosis (calcium buildup in the kidneys), nephrolithiasis (kidney stones), and kidney insufficiency. Additionally, PTH helps stabilize serum calcium levels and reduces urinary calcium loss, potentially decreasing the need for large doses of calcium and Vitamin D. PTH therapy may become a valuable addition to current treatment protocols in the future.

Hypocalcemia can range from mild, asymptomatic cases to severe, life-threatening conditions. It is important to monitor calcium-regulating hormones such as parathyroid hormone (PTH), Vitamin D, and calcitonin, as they impact the kidneys, bones, and intestines. Potential complications include:

Neurological Complications:

Neurological issues often arise from coexisting conditions or other electrolyte imbalances. These may include:

• Seizures: Low ionized calcium levels in cerebrospinal fluid can lead to increased nervous system excitability, causing seizures.
• Status epilepticus: A prolonged seizure lasting more than 5 minutes, or multiple seizures occurring within 5 minutes without regaining consciousness.
• Uremic encephalopathy: Cognitive dysfunction due to toxin accumulation from acute or chronic kidney failure, which may be linked to hypocalcemia.
• Cerebral edema: Brain swelling, which can occur in hypocalcemia among other causes.
• Coma: Severe hypocalcemia can result in a coma, with a Glasgow coma scale score below 9/15.

Cardiac Complications:

Hypocalcemia has been associated with serious heart-related complications, including:

• Reversible heart failure: In severe cases, particularly with hypoparathyroidism and hypomagnesemia, heart failure can occur but may be reversible with proper treatment.
• Torsades de pointes: A form of abnormal heart rhythm originating in the ventricles, often associated with a rapid heartbeat.
• Arrhythmias: Severe hypocalcemia can predispose individuals to life-threatening arrhythmias, requiring prompt medical intervention to correct electrolyte imbalances.

Although there are no alternative treatments for hypocalcemia, mild symptoms can often be managed by increasing the intake of calcium and Vitamin D-rich foods. These include:

1. Dairy Products: Milk, cheese, cottage cheese, yogurt, and ice cream are rich in calcium and should be consumed in moderation.
2. Nuts: Almonds and sesame seeds are good plant-based sources of calcium.
3. Beans: Beans and lentils are high in fiber and protein and also provide a good amount of calcium.
4. Broccoli: A great source of calcium, along with other nutrients like Vitamin A, C, and K1.
5. Black-Eyed Peas: Half a cup of black-eyed peas provides 8% of the daily recommended calcium intake.
6. Figs (Anjeer): A good source of both calcium and potassium, essential for bone health.
7. Oranges: Rich in calcium and Vitamin D, they help support the immune system.
8. Salmon: Fatty fish like salmon are some of the best natural sources of Vitamin D.

Calcium is essential for strong bones and teeth, and it plays a crucial role in the proper functioning of muscles and nerves. Mild cases of hypocalcemia can be managed by incorporating calcium-rich foods and making certain lifestyle changes. These include:

• Adding milk or yogurt to smoothies.
• Incorporating leafy greens into soups or pasta dishes.
• Ensuring vegetables are included in every meal.
• Including nuts and seeds like almonds and sesame seeds in your diet.
• Using yogurt as a substitute for vegetable dips.
• Taking Vitamin D and calcium supplements.
• Getting enough natural sunlight exposure.
• Wearing appropriate clothing and sunscreen to prevent blocking sunlight.
• Using UV lamps, as exposure to UV-B light helps the skin produce Vitamin D.
• Eating fortified foods.
• Exercising regularly.
• Consulting a doctor about any medications that might contribute to hypocalcemia and avoiding them.
• Including egg yolks in your diet.

Hypocalcemia is a metabolic disorder that can range from mild and asymptomatic to severe and potentially life-threatening. The treatment approach depends on the cause, severity, symptoms, and the speed of onset (acute or chronic). In most cases, hypocalcemia is mild and requires only supportive care and monitoring. For managing mild cases, some useful tips include:

• Consuming calcium-rich foods.
• Avoiding foods high in trans fats.
• Reducing alcohol consumption.
• Ensuring adequate sun exposure.
• Not staying indoors for extended periods.
• Choosing clothing and sunscreen that allow some sunlight exposure.
• Including Vitamin D-rich foods in the diet.
• Exercising regularly.
• Quitting smoking.
• Maintaining a healthy weight.
• Taking calcium and Vitamin D supplements as recommended.
• Consulting with a doctor to determine if there is an underlying cause.