Their Role in the Health of the Body and Especialy the Oral Cavity

The Macrominerals:Calcium, Phosphorus

and Magnesium

Calcium

Provides rigidity and strength to the bones and teeth

Functions

Serum calcium performs specific functions:

Contraction and relaxation of heart muscle. Helps in blood clotting Low blood calcium will increase the irritability of

nervous tissue and may cause tetany. Activate enzymes such as pancreatic lipase and

alkaline phosphatase. Activates rennin which causes curding of milk

during its digestion Necessary for the release of NTs

(neurotransmitters) Regulates transport of ions across cell membranes

Functions (cont…)

Active process Reqiures Vitamin D and calcium-binding

protein 20-30% of calcium is absorbed and the rest

are excreted in the feces, urine and perspiration.

Absorption

1. Needs of the body Growing child, pregnant, a person healing from a

bone fracture- increased calcium absorption

2. Gastric acidity Acidity in the stomach converts the insoluble

calcium salts into more soluble types

3. Hormonal influences Parathormone and calcitonin

Factors affecting absorption of Calcium

4) Vitamin D Deficiency in Vit. D- decreased calcium

absorption

5) Lactose The disaccharide lactose found in milk promotes

calcium absorption. Lactose in ileum change the intestinal bacteria

lowering the pH thus increase calcium absorption

6) Citric acid6) Its low pH promotes calcium absorption

6) Oxalic and phytic acid Intake of foods rich in oxalic such as spinach and

phytic acids found in cereal grain and meal flour causes formation of insoluble complexes (calcium salts) within intestinal lumen that leads to increased calcium absorption.

7) Fat Decreased fat, bile or salts produces insoluble

calcium thus increase calcium absorption.

11)Emotional reactions Stress may cause hormonal changes that affects

calcium metabolism

12)Exercise Weight-bearing exercise helps maintain calcium

in bone.

calcium and phosphorus are stored in the trabeculae but can be withdrawn out when it is needed in the blood

The blood and tissue calcium serve as reserves

The degree of bone development amount of calcium deposited in are directly related to the amount of the calcium available from the diet.

Storage

Out of the 100og dietary intake of calcium, 700 – 800g are excreted in feces but it could be less than that when the dietary intake is low.

During lactation, mother loses 150 -300mg of calcium daily but normally, it is not affected because of human adaptability.

Excess calcium from the bone are excreted in the urine

Unimportant daily lost of 15mg of calcium through perspiration

Excretion

Calcium in serum is regulated by the: Parathormone (PTH) Calcitonin

-serum calcium rises, PTH is inhibited -serum calcium falls, secretion of PTH increases -serum calcium rises, calcitonin increases

Role of Bone, Kidney, and Intestine

Kidney can resorb calcium Intestine - acidity Bone – activity of the osteoblast and osteoclast. How?

Regulation of calcium balance

Vitamin D Necessary for normal intestinal absorption of

calcium and helps maintain bone cells, thus regulating serum calcium and serum phosphate levels.

Avrage adult- 800mgInfants- 360-450mg1-10 yrs.old – 800mg11-18 yrs.old- 1200mgDuring lactation- 1200mg

*all daily

Recommended Dietary Allowance and Sources

Cheddar cheese – highest level of calciumBest sources are hard cheese, milk, and dark

green leafy vegetables (the darker the green, the more calcium),

Good sources are ice cream, blackstrap molasses, broccoli, baked beans, dried legumes, and dried figs.

Fair sources are cottage cheese, string breans, parsnips, lima beans lettuce and other sald greens, eggs and bread.

Sources

Calcium carbonate or oyster shell calcium is frequently recommended for persons who cannot eat dairy products.

When children refuse to drink milk, it should be incorporated either in fluid or powder form in soups, gravies, casseroles, or baked goods.

Calcium supplements