Disorders of calcium metabolism: Difference between revisions

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Disorders of Calcium Metabolism

Calcium is a vital mineral in the human body.

Disorders of calcium metabolism are a group of medical conditions that affect the regulation of calcium levels in the body. Calcium is an essential mineral that plays a critical role in various physiological processes, including bone formation, muscle contraction, nerve function, and blood clotting. The balance of calcium in the body is tightly regulated by the parathyroid hormone (PTH), vitamin D, and the kidneys.

Calcium Homeostasis

Calcium homeostasis refers to the maintenance of a stable concentration of calcium ions in the blood and extracellular fluid. The normal serum calcium level is approximately 8.5 to 10.5 mg/dL. The regulation of calcium involves:

Parathyroid Hormone (PTH): Secreted by the parathyroid glands, PTH increases blood calcium levels by stimulating osteoclasts to break down bone, increasing renal tubular reabsorption of calcium, and activating vitamin D.
Vitamin D: Enhances intestinal absorption of calcium and phosphate.
Calcitonin: Secreted by the thyroid gland, it lowers blood calcium levels by inhibiting osteoclast activity.

Types of Disorders

Hypercalcemia

Hypercalcemia is a condition characterized by an abnormally high level of calcium in the blood. Common causes include:

Primary Hyperparathyroidism: Overactivity of one or more of the parathyroid glands.
Malignancy: Certain cancers can cause hypercalcemia through bone metastasis or secretion of parathyroid hormone-related peptide (PTHrP).
Vitamin D Toxicity: Excessive intake of vitamin D supplements.

Symptoms of hypercalcemia can include nausea, vomiting, constipation, polyuria, polydipsia, confusion, and in severe cases, cardiac arrhythmias.

Hypocalcemia

Hypocalcemia is defined as a low level of calcium in the blood. Causes include:

Hypoparathyroidism: Reduced secretion of PTH.
Vitamin D Deficiency: Due to inadequate dietary intake, lack of sunlight, or malabsorption.
Chronic Kidney Disease: Impaired conversion of vitamin D to its active form.

Symptoms of hypocalcemia may include muscle cramps, tetany, seizures, and cardiac arrhythmias.

Diagnosis

The diagnosis of calcium metabolism disorders involves:

Serum Calcium Measurement: Total and ionized calcium levels.
PTH Levels: To assess parathyroid function.
Vitamin D Levels: To evaluate vitamin D status.
Renal Function Tests: To assess kidney function.

Treatment

Treatment of calcium metabolism disorders depends on the underlying cause:

Hypercalcemia: May require hydration, diuretics, bisphosphonates, or calcitonin.
Hypocalcemia: Treated with calcium supplements and vitamin D.

@@ Line 1: / Line 1: @@
-'''Disorders of Calcium Metabolism''' are a group of conditions that affect the balance and regulation of calcium in the body. Calcium is a vital mineral necessary for many bodily functions, including bone formation, muscle function, and nerve transmission. Abnormalities in calcium metabolism can lead to various clinical manifestations, ranging from asymptomatic laboratory findings to life-threatening conditions.
+== Disorders of Calcium Metabolism ==
-==Etiology==
+[[File:Ca-TableImage.svg|thumb|right|Calcium is a vital mineral in the human body.]]
-Disorders of calcium metabolism can arise from several causes, including:
-* [[Endocrine disorders]], such as [[hyperparathyroidism]] and [[hypoparathyroidism]], which affect the parathyroid glands' regulation of calcium.
-* [[Vitamin D deficiency]] or disorders in vitamin D metabolism, impacting calcium absorption from the gut.
-* [[Renal failure]], leading to changes in calcium and phosphate handling.
-* Genetic conditions, such as [[familial hypocalciuric hypercalcemia]] (FHH) and [[autosomal dominant hypocalcemia]].
-==Pathophysiology==
+Disorders of calcium metabolism are a group of medical conditions that affect the regulation of calcium levels in the body. Calcium is an essential mineral that plays a critical role in various physiological processes, including bone formation, muscle contraction, nerve function, and blood clotting. The balance of calcium in the body is tightly regulated by the [[parathyroid hormone]] (PTH), [[vitamin D]], and the kidneys.
-The regulation of calcium levels in the body is a complex process involving the [[bones]], [[kidneys]], and [[gastrointestinal tract]], under the control of parathyroid hormone (PTH), vitamin D, and the calcitonin hormone. Disorders in any of these regulatory mechanisms can lead to disturbances in calcium metabolism.
-===Hypercalcemia===
+== Calcium Homeostasis ==
-Hypercalcemia refers to elevated calcium levels in the blood. It can result from increased intestinal absorption, increased bone resorption, or decreased renal excretion of calcium. Common causes include hyperparathyroidism, malignancy, and vitamin D intoxication.
-===Hypocalcemia===
+Calcium homeostasis refers to the maintenance of a stable concentration of calcium ions in the blood and extracellular fluid. The normal serum calcium level is approximately 8.5 to 10.5 mg/dL. The regulation of calcium involves:
-Hypocalcemia is characterized by low levels of calcium in the blood. It can occur due to inadequate calcium intake, impaired calcium absorption, or excessive calcium loss. Causes include hypoparathyroidism, vitamin D deficiency, and renal disease.
-==Clinical Manifestations==
+* '''Parathyroid Hormone (PTH):''' Secreted by the [[parathyroid glands]], PTH increases blood calcium levels by stimulating osteoclasts to break down bone, increasing renal tubular reabsorption of calcium, and activating vitamin D.
-Symptoms of calcium metabolism disorders vary widely and depend on the severity and rate of change of blood calcium levels.
+* '''Vitamin D:''' Enhances intestinal absorption of calcium and phosphate.
+* '''Calcitonin:''' Secreted by the [[thyroid gland]], it lowers blood calcium levels by inhibiting osteoclast activity.
-===Hypercalcemia===
+== Types of Disorders ==
-Symptoms of hypercalcemia may include polyuria, polydipsia, kidney stones, nausea, vomiting, constipation, muscle weakness, and cognitive disturbances.
-===Hypocalcemia===
+=== Hypercalcemia ===
-Hypocalcemia can present with neuromuscular irritability, including tetany (involuntary muscle contraction), seizures, prolonged QT interval on ECG, and psychiatric manifestations.
-==Diagnosis==
+[[Hypercalcemia]] is a condition characterized by an abnormally high level of calcium in the blood. Common causes include:
-Diagnosis of calcium metabolism disorders involves a thorough history, physical examination, and laboratory tests. Key laboratory tests include serum calcium, phosphate, magnesium, PTH, and vitamin D levels. Additional tests, such as urinary calcium excretion, may be necessary to determine the underlying cause.
-==Treatment==
+* '''Primary Hyperparathyroidism:''' Overactivity of one or more of the parathyroid glands.
-Treatment of disorders of calcium metabolism aims to correct the underlying cause and restore calcium balance.
+* '''Malignancy:''' Certain cancers can cause hypercalcemia through bone metastasis or secretion of parathyroid hormone-related peptide (PTHrP).
+* '''Vitamin D Toxicity:''' Excessive intake of vitamin D supplements.
-===Hypercalcemia===
+Symptoms of hypercalcemia can include nausea, vomiting, constipation, polyuria, polydipsia, confusion, and in severe cases, cardiac arrhythmias.
-Treatment options for hypercalcemia may include hydration, bisphosphonates, calcitonin, and in severe cases, dialysis.
-===Hypocalcemia===
+=== Hypocalcemia ===
-Hypocalcemia treatment typically involves calcium supplementation and vitamin D therapy. In acute cases, intravenous calcium may be required.
-==Prevention==
+[[Hypocalcemia]] is defined as a low level of calcium in the blood. Causes include:
-Preventive measures for disorders of calcium metabolism focus on adequate intake of calcium and vitamin D, regular exercise, and monitoring in individuals at risk.
-==Conclusion==
+* '''Hypoparathyroidism:''' Reduced secretion of PTH.
-Disorders of calcium metabolism encompass a wide range of conditions with diverse etiologies and clinical manifestations. Early recognition and appropriate management are crucial to prevent complications and improve outcomes.
+* '''Vitamin D Deficiency:''' Due to inadequate dietary intake, lack of sunlight, or malabsorption.
+* '''Chronic Kidney Disease:''' Impaired conversion of vitamin D to its active form.
-[[Category:Endocrinology]]
+Symptoms of hypocalcemia may include muscle cramps, tetany, seizures, and cardiac arrhythmias.
-[[Category:Metabolic disorders]]
-{{medicine-stub}}
+== Diagnosis ==
+The diagnosis of calcium metabolism disorders involves:
+* '''Serum Calcium Measurement:''' Total and ionized calcium levels.
+* '''PTH Levels:''' To assess parathyroid function.
+* '''Vitamin D Levels:''' To evaluate vitamin D status.
+* '''Renal Function Tests:''' To assess kidney function.
+== Treatment ==
+Treatment of calcium metabolism disorders depends on the underlying cause:
+* '''Hypercalcemia:''' May require hydration, diuretics, bisphosphonates, or calcitonin.
+* '''Hypocalcemia:''' Treated with calcium supplements and vitamin D.
+== Related Pages ==
+* [[Calcium in biology]]
+* [[Parathyroid hormone]]
+* [[Vitamin D]]
+* [[Bone metabolism]]
+{{Disorders of calcium metabolism}}
+[[Category:Endocrine disorders]]
+[[Category:Calcium]]