2. MINERALS IN HUMAN HEALTH

3. Learning Outcomes Distribution in the body Dietary sources
Daily Requirements
Absorption / Excretion
Factors affecting Calcium Absorption

4. At.No.20 Calcium At .Wt 40

5. BONES AND SKELETON
Higher animals have an internal frame work – endoskeleton
Skeleton is made almost entirely of a hard, rigid tissue – bone
Bone consists like other living tissues of living cells suspended in an inert ground substance

6. GROUND SUBSTANCE OF BONES is
The determining factor of bone characteristic properties
Network of protein fibers with insoluble mineral salts Mostly phosphate of calcium.
Responsible for hardness of bone

7. BONE GROWTH Bone grows by the activity of osteoblasts.
These have enzyme which separates Insoluble calcium phosphate from soluble phosphate in blood by precipitation
Osteoblast will do their work only if the essential elements of bones are present in diet in reasonable quantity.
Of course the dietary minerals will have to be absorbed properly which depends on many factors.

8. Distribution More than 99% of calcium is in bones and teeth
Ca++ in bone constantly exchanged with that of interstitial fluid.
0.03% of Total Body calcium in blood
Normal Serum / plasma contains 9 – 11 mg/dl
RBCs contain very little Ca++
Regulated by PTH, Vit - D3 and calcitonin

9. In plasma Ca++ occurs in two forms
Non diffusible
3.4 – 4.4 mg/dl
Combined with plasma proteins (Albumin)
Not dialyzable
Low in hypoproteinemia

10. In plasma Ca++ occurs in two forms
Diffusible
Ionized
5.45 – 6.23 mg/dl
Physiologically active
 Hyperparathyroidism
 Hypoparathyroidism
If level drops to 4.3 mg/dl Tetany occurs

11. Dietary sources Milk and Dairy products
Hard cheese concentrated source
Cottage cheese and ice cream
Egg yolk , leafy vegetable
Water

12. Dietary sources Shrimps, oysters and salmon
Mustard green, turnip and spinach
Whole wheat bread
Inorganic salts CaCl2, CaCo3

13. Dietary sources
When diet is deficient : salts of Calcium with carbonate, gluconate, lactate, Sulphate may be taken as supplement
Milk and milk products:
2 – 3 cups /day -Adults
3 – 4 cups/day Children

14. Recommended Dietary Allowance
Infants 0 – 0.5 years mg.
0.5 –
Children 1 –
4 –
7 –

15. Recommended Dietary Allowance
Male / Females 11 –
15 –
19 –
23 –
Pregnancy
Lactation

16. Absorption
Both organic and inorganic forms of Ca++ are utilized and absorbed
Mostly in proximal part of small intestine

17. Absorption
Calcium is absorbed against a concentration gradient and requires energy.
Requires a carrier protein
Helped by calcium dependent ATP ase.

18. Absorption Absorbed by active transport mechanism in two steps
Uptake of calcium through Ca++ specific channels
Efflux – Ca++, Mg++ and ATPase
Some absorption through passive transport / facilitated diffusion

20. Kidneys filters out calcium
Calcium is
absorbed by GIT
Soft tissue
Calcium
Extra Cellular
Fluid
Calcium in
Bone
Kidneys filters out calcium

23. Factors affecting calcium absorption
Vitamin – D
Increases the absorption of calcium
Increase the specific transport protein responsible for active transport of calcium in proximal small intestine wall

24. Factors affecting calcium absorption
2. PTH
 calcium absorption but effect is less marked than vitamin D
3. Calcium : P when 1 : 2 or 2 : 1 in food
optimum absorption
4. Excess of Po4 in GIT  calcium absorptio
240 mg Ca++ absorbed/day

25. Presence of FFA Excessive fat intake lowers Ca absorption .
Due to impairment in absorption , free fatty acid react with free calcium and forms insoluble complex ( Ca-soaps)
Bile salts increase absorption of Ca++ by properly absorbing FFA & prevents formation of Ca-complexes

26. Presence of Anions
Oxalates, carbonates and sulfates inhibit Ca++ absorption as Ca complexes with these are insoluble
Ca++ salts with chloride , glucose and lactate are soluble & absorbed to greater extent.
Ca++ salts with AA from proteins taken in diet, are more soluble in aq. Solutions of AA & thus facilitate Ca++ absorption.

27. Intestinal pH.
Ca++ is well absorbed in acidic medium .If pH is low, calcium salts are more soluble.

28. Calcium Deficiency
If the body is deficient in Calcium, then increased absorption and this is mediated through an increased parathyroid activity

29. Less calcium is absorbed in old age

30. Intestinal Disease like Malabsorption , Ceolic Diseases , and Steathorea decrease Ca++ absorption
Idiopathic hyper calcaemia ,Ca++ absorption from intestine is greatly increased due to unknown reasons.