presentation of serum calcium

3. OBJECTIVE OF SESSION
 Identify normal blood Calcium level
 Identify calcium function ,distribution
and sources
 Identify factors affecting blood calcium
level
 Recognize or understand the causes of
hyocalcemia and hpercalcemia
 Measure the calcium level in serum and
interpret the result

4. Total content in 70 kg adult: 1- 1.5 kg
99% of calcium is found in the skeleton
(bone and teeth)
1% of calcium is found in other tissues and
body fluids.
Body distribution

5. Blood calcium
• Normal level is 9-11 mg/dl
• Distributed as follows
 Free calcium (ionized)(50%) --- 5mg/dl
it is physiologically the active” form.
 Protein bound calcium (40%) --- 4mg/dl
Bound mainly to albumin.
 Calcium bound to non protein carrier(10%)
--- 1 mg/dl
It is Complexed with bicarbonate, phosphate
and citrate.

6. • Hypoalbunemia result in ↓ blood Ca
1gm decline in albumin causes ↓ 0.8 mg/dl of
Ca
• Hyperproteinemia causes ↑ 𝑖𝑛 blood Ca
• Acidosis favours the release of ionized
calcium
• Alkalosis favours the calcium binding and
decrease ionized form while total Ca is
normal

7. Major functions
 Calcification of bone and teeth
 Muscle contraction
 Role in neuromuscular transmission
 Role in blood coagulation

8. Sources
Very rich
sources
Fair amount
sources
Milk, cheese and
yoghurt
Vegetables, fruits
and egg yolk

9. Calcium homeostasis is regulated by:
1. vitamin D (calcitriol)
2. parathyroid hormone (PTH)
3. calcitonin
CALCIUM HOMEOSTASIS

10. 1- Calcitriol (active vit. D):-
Intestine:
Increase the
absorption of
calcium
Bone:-
mobilization of
calcium and
phosphate
from bone.
Kidneys:-
Increase
reabsorption
of calcium
and
phosphate
Calcitriol increases the
plasma level of calcium

11. 2-Parathyroid hormone
Intestine:-
Indirectly
By promoting
synthesis of
calcitriol
Bone:-
Increase the
mobilization of
calcium from
bone
Kidneys:-
Increase
reabsorption
of calcium
from kidney
tubule
PTH is released on drop of
serum calcium
PTH increases the serum
level of calcium.

12. Bone:-
Reduces osteoclastic
activities by reducing
number and size of
osteoclasts.Thus,
inhibits bone resorption
Kidneys:-
it decreases
calcium
reabsorption.
•Calcitonin is released
from parafollicular cell
of the thyroid gland.
•It decrease the serum
level of calcium.

13. CALCIUM, PTH, AND VITAMIN D
FEEDBACK LOOPS
NORMAL BLOOD Ca
RISING BLOOD Ca
FALLING BLOOD Ca
SUPPRESS PTH
STIMULATE PTH
BONE RESORPTION
URINARY LOSS
1,25(OH)2 D PRODUCTION
BONE RESORPTION
URINARY LOSS
1,25(OH)2 D PRODUCTION

14. Hypo-calcemia
In children :
In adults:
Rickets
osteomalacia
Causes: Hypoparathyroidism
Pseudohypoparathyroidism
(Normal parathyroid hormone secretion
with end organ resistance)
Vit D deficiency
Malabsorption
Malnutrition
Renal disease
Liver disease

15. Hyper-calcemia
Causes:
Hyperparathyroidism
Paget disease
Malignancy
Vitamin D overdose

16. The experiment

17. Blank Standard Test
Reagent 1 ml 1 ml 1 ml
water 20 μl
Standard 20 μl
Serum 20 μl
Estimation of serum calcium:-
Mix and incubate for 5 minutes at 20-25˚C.
Measure absorbance of test and standard against reagent
blank.
Wavelength: 585 nm (575- 590 )
Calculation:
Calcium concentration = A. of test × conc. Of standard
A. of standard

18. Case 1
• A 2-year-old boy was brought to our hospital because of absent
teeth development and failure to walk. The patient appeared to
be well nourished. His body mass index was 19.1 kg/m2 (90th
percentile), he was 86 cm long (25th percentile) and he weighed
13.6 kg (75th percentile). Palpation of the patient's extremities
revealed prominent, flared distal radii, humeri and femurs. Total
serum calcium was 8 mg/dl and serum albumin was 4gm/dl.
• 1. Interpret the result of calcium level
• 2. Mention two possible causes of hypocalcemia
• 3. if albumin is 1.9 g/dl , What is boy corrected calcium
level?

19. Case 2
• A 50-year-old man presented at hospital with vomiting,
polyuria, abdominal pain, weight loss, fatigue and muscular
weakness. He is hypertensive on thiazide diuretic. No
history of calcium or Vit D supplement intake . Serum
calcium was 23 mg /dl .
• Comment on calcium level
• Mention two possible causes of altered Ca level in such
case .