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calcium and phosphorus are stored in the trabeculae but can be withdrawn out when it is needed in the blood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