Toxicity

Hypercalcemia (excess calcium in the blood)

Hypercalcinuria (excess calcium in the urine)

Kidney stones (result in high levels of calcium in the serum and urine calcification of soft tissues)

Hyperparathyroidism

PHOSPHORUS

One of the most essential elements of the body

Available in all foods of plant and animal origin

Second most abundant mineral in body, after calcium

>600 g of phosphorus in the normal human body, 80-90% combined with calcium to form bones and teeth

Absorption and Metabolism

Dietary phosphorus intake : 1.5 g/day

Phosphorus balance is regulated by the metabolic and hormonal factors vitamin D, calcitonin, parathyroid hormone

Amount of phosphorus in the body is controlled by excretion in the urine rather than by absorption

Function

Major functions:-formation of bone and tooth mineral-production and transfer of high-energy phosphates

Plays a role in absorption and transport of nutrients

Regulates the acid-base balances Plays an important role in cell protein synthesis

(part of the nucleic acids DNA and RNA, the substances that control heredity)

Buffers in blood and tissue (chemicals that prevent change in the concentration of other chemicals)

Attachment of phosphate to the matrix of bone and teeth is one of the initial steps in their mineralization

Failure of bone calcification results from a lack of phosphorus as often as from a lack of calcium

Increase in serum alkaline phosphatase is associated with poor bone calcification as seen in rickets (vitamin D deficency disease resulting in bone deformities) and osteomalacia (softening of the bone in adults)

Recommended Dietary Allowances and Sources

Intakes of 800 to 1200 mg of phosphorus daily are recommended

Animal foods rich in protein are also rich in phosphorus (meat, fish, poultry, eggs and milk)

Nuts, legumes and whole-grain cereals are also good sources of phosphorus

* Excess dietary phosphorus in animals will increase bone loss and bone porosity (significantly decrease bone mineral and cause calcification of the kidney, tendons, heart and thoracic aorta)

Osteoporosis

A condition in which the rate of bone resorption is greater than the rate of bone formation, resulting in decreased bone density and a reduction in the total bone mass

Caused by deficiencies of calcium and estrogen hormone

OSTEOMALACIA

Abnormal bone calcification

Due to:- deficiency of Vitamin D, Calcium and phosphates

Results in:- excessive uncalcified osteiod-Abnormal bone mineral composition

Clinical Manifestations:-weakness-aching

Treatment-dietary calcium and vitamin D

OSTEOPOROSIS

Abnormal organic matrix formation

Due to:-deficiencies of calcium and estrogen

Results in:-decreased ossification (forming activity)-mineral composition of bone remains normal

Clinical Manifestations:-hip and back pain-decreased height-tendency to bone fracture

Treatment-estrogens, protein, calcium, vitamin D and fluoride

FACTORS INDICATE GREATER RISK OF OSTEOPOROSIS

Heredity Smoking Alcohol Coffee(5 or more cups daily) Low calcium intake Certain levels of hormones, PTH,

calcitonin, estrogen, androgen, insulin, growth hormone, throid hormones, protein

Drugs like phenytoin (anticonvulsant) and phenobarbital

Clinical diagnosis

Osteoporosis occurs most commonly in older people, >60 age

Osteoporotic individuals tends to have a lower intake and a higher urinary excretion of calcium than normal persobs

Loss of height because of shortening of the trunk and collapsed of the vertebrae

Therapy

Ingestion of high calcium diets , estrogen, fluoride, calcitonin, PTH, active form of vitamin D

Estrogen and diet: reduces vertebral, hip and forearm fractures

Fluoride: large doses of fluoride can stimulate bone formation

Calcitonin: can increase bone mass PTH increases with age, also found to

increase bone mass