This document discusses calcium metabolism and disorders. It defines calcium and its daily requirements. Calcium levels are regulated by parathyroid hormone, vitamin D, and calcitonin. Disorders include hypercalcemia caused by overactive parathyroids, and hypocalcemia caused by deficiencies. Hyperparathyroidism has primary, secondary, and tertiary forms caused by changes in calcium levels. The case discusses an older patient with hypercalcemia, high PTH, and symptoms of fatigue from possible primary hyperparathyroidism.

1. CALCIUM
METABOLISM
DISORDERS

2. OVERVIEW:
 Calcium definition and requirement .
 Calcium metabolism regulators : VD , PTH and
calcitonin.
 Functions of calcium.
 Calcium metabolic bone diseases.
 Calcium metabolism disorders.
 CASE !!

3. WHAT IS CALCIUM?
 Calcium is a mineral that is
essential to bone health,
cardiovascular health, muscle
maintenance, circulatory health, and
blood clotting. Calcium also acts as
an enzyme activator. While calcium
is found in milk and dairy products,
it is also available from other food
sources, such as green leafy
vegetables, seafood (eating salmon
with the bones provides an even
greater dose), almonds, blackstrap
molasses, broccoli, enriched soy and
rice milk products, figs, soybeans
and tofu.

4. BODY REQUIREMENTS
 Age (in years) Calcium Requirement
 1 – 3 500mg
 4 - 8 800mg
 9 - 18 1300mg
 19 - 50 1000mg
 51+ 1500mg
 *Pregnant and lactating women are
recommended a daily calcium intake of 1000mg.

5. DIFFERENT FORMS OF CALCIUM
At any one time, most of the calcium in the body exists as
the mineral hydroxyapatite, Ca10(PO4)6(OH)2.
Calcium in the plasma:
45% in ionized form (the physiologically active form)
45% bound to proteins (predominantly albumin)
10% complexed with anions (citrate, sulfate,
phosphate)
To estimate the physiologic levels of ionized calcium in
states of hypoalbuminemia:
[Ca+2
]Corrected = [Ca+2
]Measured + [ 0.8 (4 – Albumin) ]

6. REGULATING FACTORS
 It is regulated by :
 PTH and 1,25-(OH)2D3 on gut, kidney and bone
 Calcium receptors:
 are present in the parathyroid gland, kidney ,
brain and other organs.

7. VITAMIN D METABOLISM
 The active form of vitamin D is 1,25-
dihydroxycholecalcififerol. Its production in the
kidney is catalyzed by 1 a-hydroxylase .
1 a-hydroxylase activity is increased by :
 Decreased serum Ca2+
 Increased PTH level
 Decreased serum phosphate

8. ACTION OF 1,25-
DIHYDROXYCHOLECALCIFIFEROL(CALC
ITRIOL(
 Increases intestinal Ca2+ absorption
 Increases intestinal phosphate absorption
 Increase renal reabsorption of Ca2+ and phosphate
 Increases resorption of bone

9. PARATHYROID HORMONE (PTH(:
 it is an 84-amino-acid hormone.
Secretion:
 from the chief cells of the
parathyroid glands.
Function:
increase renal phosphate excretion , and increases plasma
calcium by:
 Increasing osteoclastic resorption of bone (occurring
rapidly).
 Increasing intestinal absorption of calcium (a slower
response).
 Increasing synthesis of 1,25-(OH)2D3 (stimulating GIT
absorption).
 Increasing renal tubular reabsorption of calcium

10. REGULATION OF PTH
 Low serum [Ca+2
]  Increased PTH secretion
 High serum [Ca+2
]  Decreased PTH secretion

11. LCITONIN
Produced by :
 thyroid C cell.
Function:
 Inhibition of osteoclastic bone resorption .
 Increasing the renal execration of calcium and
phosphate.
 Stimulant ??

13. IBITING FACTORS
 The amount of calcium consumed at
one time can also affect absorption.
In other words, calcium absorption
decreases as the amount of calcium
consumption increases in a meal.
Thus, spreading consumption of
calcium throughout your day is best.
 Age

14. CONT,
 Fiber, particularly from wheat bran, could also
prevent calcium absorption because of its content
of phytate
 dietary sodium and protein increase calcium
excretion as the amount of their intake is
increased
 Caffeine has a small effect on calcium absorption.
It can temporarily increase calcium excretion and
may modestly decrease calcium absorption,

15. FUNCTIONS
 Muscle contraction
 Signal transmission
 Body structure

16. DEFICIENCY:
Deficiency of calcium levels in the body may
induce several diseases:
 Rickets disease
 Adult osteomalacia
 osteoporosis

17.  Rickets :
is a softening of bones in children potentially leading
to fractures and deformity. The predominant cause is a
vitamin D deficiency, lack calcium in the diet may also
leads to rickets
 Osteomalacia :
is the softening of the bones due to
defective bone mineralization It may
show signs as diffuse body pains, fragility
of the bones. A common cause of the disease is
deficiency in vitamin D, which is normally obtained
from the diet and/or sunlight exposure

18.  Osteoporosis
a disease characterized by low bone mass and structural
deterioration of bone tissue, leading to bone fragility
and an increased risk of fractures of the hip spine, and
wrist, leading to bone fragility. Men as well as women
are affected by osteoporosis. women had high rate to
be affected by osteoporosis

20. CALCIUM METABOLISM
DISORDERS:
Calcium metabolism disorder include:
 Hypercalcemia
 Hypocalcemia
 hyperparathyrodism

21. HYPERCALCEMIA
 Is condition in which the calcium level in the
body is above the normal.
 The need of the calcium for the bone formation
and muscle contraction, releasing hormone .
 The main cause is over activity of the
parathyroid gland.
 cancer and some medication may cause over
activity of the calcium level.

22. ETIOLOGY OF HYPERCALCEMIA

23. COMPLICATION:
 Metastatic calcification
 Renal stones

24. HYPOCALCAEMIA
 Is a condition in which the calcium level below
The normal level
 Is caused by low level of PTH , low level of
magnesium, deficiency of vitamin D
 The kidney dysfunction play role in hypocalcuimia

25. ETIOLOGY OF THE
HYPOCALCEMIA
 Decreased GI Absorption
 Poor dietary intake of calcium,impair absorption
 Increased Urinary Excretion
 Decreased Bone Resorption/Increased Mineralization
 Low PTH
 PTH resistance
 Vitamin D deficiency,

26. COMPLICATION
.Tetany: condition of mineral imbalance in the
body that results in severe muscle spasms.
usually occurs when the concentration of
calcium ions (Ca++) in extracellular fluids below
normal

27. HYPERPARATHYROIDISM.
 Hyperparathyroidism occur in two major forms:
 Primary: most common cause of
hypercalceimia.it represents autonomous
production of PTH.
 Secondary:is caused by any chroinc condition
assocaited with chroinc depression in the calcuim
level.
 Tertiary hyperparathyroidism: rarely occur

28. CASE 1
a 59 year old woman with a past medical history
significant for hypertension who comes for a
routine clinic visit. She initially states that she
has no symptomatic complaints, but later in the
interview describes chronic fatigue and a mildly
depressed mood. Her exam is unremarkable. She
used thiazide diuretics as treatment for
hypertension, Labs results showed:
Calcium (total) – 11.9 mg/dL(normal ~ 8.5-10.2 mg/dL(
Phosphate – 1.8 mg/dL(normal ~ 2.0-4.3 mg/dL(
Albumin – 3.8 g/dL(normal ~ 3.5-5.0 g/dL(
PTH – 124 pg/mL(normal ~ 10-60 pg/mL(
Creatinine – 1.2 mg/dL

29. Thank You