Calcium Metabolism

2. DISORDERS OF CALCIUM
METABOLISM
Dr Shamim Akram

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14. ETIOLOGIES OF HYPERCALCEMIA
Increased GI Absorption Decreased Bone
Milk-alkali syndrome Mineralization
Elevated calcitriol
Vitamin D excess Elevated PTH
Excessive dietary intake Aluminum toxicity
Granuomatous diseases
Elevated PTH
Hypophosphatemia Decreased Urinary Excretion
Increased Loss From Bone Thiazide diuretics
Increased net bone resorption Elevated calcitriol
Elevated PTH
Hyperparathyroidism Elevated PTH
Malignancy
Osteolytic metastases
Increased bone turnover
Paget’s disease of bone
Hyperthyroidism

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CAUSES
Approx. 80% of all cases are caused by
Malignancy or Primary Hyperpathyroidism
• V Vitamins  T Thiazide,
• I Immobilization other drugs - Lithium
• T Thyrotoxicosis  R Rabdomyolysis
• A Addison’s disease  A AIDS
• M Milk-alkali syndrome  P Paget’s disease,
• I Inflammatory disorders Parental nutrition,
Pheochromocytoma,
• N Neoplastic related Parathyroid disease
disease
• S Sarcoidosis

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18. SIGNS AND SYMPTOMS
 Bones, stones, abdominal groans, and
psychic moans.
• Malaise, fatigue, headaches, diffuse
aches and pains, constipation.
• Patients are often dehydrated
• Lethargy and psychosis when
hypercalcemia is severe.
• Calcifications in
skin, cornea, conjunctiva, and kidneys.
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19. CLINICAL
1. Renal ; , stone, nephrocalcinosis
2. GI ;, Constipation, PU, Pancratitis
3. Neuro ; Weakness, Drowsiness, Apnea
4. Cardio ; Short QT <0.3 ,Broad T, Heart
Block, Vent arrhythmia,Asystole, Sense
to digoxin
5. Musculo ; Cramp, Bone
pain, Pathologic Fx
6. Others ; Band Keratopathy
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21. DIAGNOSIS
 Detailed history and physical examination…
 PTH level
 Vitamin D level
 Serum calcium levels
 Urine evaluation
 Ultrasound
 X-RAYS,MRI,CT scan
 PET(Positron Emission Tomography

22. MANAGEMENT HYPERCALCEMIA
 General
 Hydration 2-4L/day Keep urine output > 1-2
ml/kg/hr onset 12-24 hr
 Lasix 10-20 mg iv. q 6-12 hr * only after
adequate hydration *
 Mobilization
 Dialysis
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23. MANAGEMENT HYPERCALCEMIA
 Specific
 Calcitonin
 Bishosphonates
 Galliumnitrite
 Plicamycin, Mithramycin
 Hydrocortisone
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24. ETIOLOGIES OF HYPOCALCEMIA
Decreased GI Absorption
Poor dietary intake of calcium
Impaired absorption of calcium
Vitamin D deficiency
Increased Urinary Excretion
Poor dietary intake of vitamin D
Malabsorption syndromes Low PTH
Decreased conversion of vit. D to thyroidectomy
calcitriol
Liver failure I131 treatment
Renal failure Autoimmune hypoparathyroidism
Low PTH
PTH resistance
Hyperphosphatemia
Vitamin D deficiency / low calcitriol
Decreased Bone Resorption/Increased
Mineralization
Low PTH
PTH resistance pseudohypoparathyroidism)
Vitamin D deficiency / low calcitriol
Hungry bones syndrome
Osteoblastic metastases

25. SYMPTOMS AND SIGNS OF HYPOCALCEMIA
 Neuromuscular irritability
 Paresthesias
 Laryngospasm / Bronchospasm
 Tetany
 Seizures
 Chvostek sign
 Trousseau sign
 Prolonged QTc time on ECG

28. Trousseau sign:
(very uncomfortable and painful)
 A blood pressure cuff is
inflated to a pressure
above the patients
systolic level.
 Pressure is continued for
several minutes.
 Carpopedal spasm:
* flexion at the wrist
* flexion at the MP joints
* extension of the IP joints
* adduction
thumbs/fingers

29.  Long QT interval with
normal T waves
 Prolongation of the ST
segment with little shift
from the baseline

30. TREATMENT HYPOCALCEMIA
 Symptomatic hypocalcemia needs IV calcium and
continuous monitoring for arrhythmias.
 Once serum Ca is in safe range ( >7 mg/dl) IV Ca
can be stopped, and oral Ca started.
 Oral Ca and vit D are initiated as soon as possible
when patient is tolerating oral feed.
 Active form of vit D is preferred in treatment of
HPH and hyperphosphatemia because both
impair activation of 25 OH vit D by one alpha
hydroxylase.
 Diet, no specific diet is required but adequate Ca
and vit D intake is recommended.

31. Thank you