2. Needs for Calcium n Bone strength.  Calcium as calcium phosphate constitutes 50% of bone mass.  An adult has about 1,000,000 mgms. Of calcium in bone n Muscle contraction Too much or too little causes tetany n Nerve stimulation n Internal cell communication (second messengers)  Carries hormonal messages to the inside of the cell

3. Control of Blood Calcium n Most accurately controlled of all blood material  Due to it’s many physiological roles. n Calcium is absorbed or deposited in/from –Intestine, –bone –urine –soft tissue n Regulated by hormones blood increase: Parathyroid hormone (PTH) and Vit.D blood decrease …..Calcitonin

4. Hormone Control of Calcium

5. Uptake of Calcium

6. Absorption of Calcium Calcium balance: Urine: 90mgm = +ve 100mgm = 0 110 mgm = -ve

7. Intestinal Absorption n Most of the calcium intake is unavailable o Insoluble phosphates n Plant complexing compounds –Oxalic acid –phytic acid n Best source is milk or meat –others may not be absorbed n Need Vit D ( sun light)

8. Calcium Balance n Calcium intake - Calcium excretion  +Ve means bones getting stronger /bigger  -VE means bones getting weaker n Intake increased / needs Ö Vit D Ö Calcium binding proteins Ö adequate diet ( most females take 50% RDI) n Excretion increased by :  inactivity  high protein diets  caffeine  low estragon (menopause or body fat)

9. Hypercalciuric Effect of High Protein Diets

10. Effect of Age n Negative balance normal after age 30- 35 Gradual loss until bones break n Osteoporosis physiological ( starts at age 35) pathogenic ( age 50 or later) n No way to stop loss  Calcitonin treatment for aged  minimised by excersise (bone stress)  Best protection is strong bones when young

11. Osteoporosis

12. Susceptible Individuals n More susceptible –Tall thin females –Inactive people –type one diabetes –high protein diets n Less susceptible –short fat people –type two diabetes –moderate protein diets

13. Pre-diabetic individuals n Normal individuals remove glucose from the blood using insulin n Test with Glucose Tolerance Test n Normal GTT means adequate insulin production n Diabetes means means glucose not removed and too much in blood –Type One No insulin produced –Type Two insulin does have effect –Pre-diabetics produce more insulin to produce a normal Glucose Tolerance Test n Do not show hypercaliuric effect with high protein diets

14. Glucose Tolerance Test

15. Pre-diabetic GTT