Phosphorus in Human Body

Phosphorus is widely distributed in foods. The best food sources include protein rich foods like meat, poultry, fish, eggs milk and milk product. Phosphorus is a constituent of nucleic acids, phospholipids and adenosine triphosphate.

Phosphorus is contained in the complex fat and protein compounds which are necessary for the vital bodily processes since they are present in the essential cell structure, in the cell nucleus, in the nerve cells and even in the sex cells.

Phosphorus is a constituent of the high energy compound ATP and thus is necessary for energy transductions essential for all cellular activity.

The energy released as the phosphate bond of ATP is broken provides for numerous cellular functions such as active transport pumps for nutrient absorption and for maintenance of ion concentrations, muscle cell contractions.

The active coenzyme form of certain of the B vitamins also functions as the phosphorylated derivatives.

Phospholipids are constituents of all cellular membranes and are active determinants of cellular permeability. Phospholipids which are present in various cells of human body, contain phosphorus. It aids in providing transport of fat in the blood. Inorganic phosphates in the body fluids act as a buffer system in the body. 

Phosphate is an important component of the nucleic acids DNA and RNA alternating with pentose sugars to form the linear backbone of these molecules. DNA and RNA, the genetically compounds are responsible for cell reproduction and therefore for growth and all protein syntheses.
Phosphorus in human body

Recommended Intake of Calcium

Calcium plays a key role in the integrity of the skeleton. Adequate intakes throughout childhood and adolescence are essential for optimal peak bone mass, which occurs between 20 and 30 years of age.

The RDA for children (1-10 years) and adults 25 years and older is 800 mg/day.

The recommended dietary allowance (RDA) for the adult male and female (800 mg/d) has been based upon calcium balance studies conducted with groups of individuals accustomed to ample intakes of the mineral.

Additional calcium (1200 mg) has been recommended during adolescence when rapid growth and bone mineralization are occurring. Government surveys have revealed, however, that much of the population (particularly females over 12 years of age) fails to consume the recommended amounts of calcium.

All these amounts of calcium can easily be obtained if dairy products are included in the diet. A balanced diet furnishes, in addition to calcium, other nutrients necessary for bone health.

Calcium metabolism in adolescent is not fully understood. Researcher found that the growth demands of girls were met by a more effective net absorption and retention of calcium compared with the young adult women, suggesting that the body is able to respond appropriately to increased need.

Inadequate calcium intake during the period of bone mineralization is a real concern because of the high incidence of osteoporosis among elderly women and the significantly correlation shown to exist between present bone density and past calcium intake.

The calcium absorption rate has been reported to increase during pregnancy and lactation. This evidence suggest it is prudent to recommend a calcium intake of 1200 mg throughout pregnancy and lactation, irrespective of age.

When body mass is taken into account, growing children require as much as two to four times as much calcium as adults and the United States recommended dietary allowance for calcium is greatest during adolescence (11-18 years) and early adulthood (19-24 years), being in the order of 1200 mg/day.

Although the exact age at which peak bone mass is achieved is uncertain, it is believed to be no earlier than 25 years. Meanwhile 800 mg/d is sufficient for the adult woman (over 25 years) even after menopause. Postmenopausal osteoporosis is regarded primarily as a medical rather than a nutritional problem.

Adequate calcium should be obtained through ingesting calcium rich foods.

The reason for poor calcium intake amongst female athletes and non-athletes lies in the lack of knowledge about good calcium sources and a desire for leanness. It is a common misconception that all dairy sources of calcium are high in fat.
Recommended Intake of Calcium

Functions of Calcium in Human Body

Calcium is an essential for all living things. Calcium is important for hormonal activities and essential for fertilization and cell division. The element also controls the mechanical stability of the walls and membranes in cells and stimulates muscle contortions.

Bone is the body’s calcium nutrient reserve. Mineralization of bones and teeth is the function of calcium that demands the lion’s share of the mineral (approximately 99% of the total body calcium). Nevertheless the small amount of remaining body calcium essential to the function of many tissues, including the clotting of blood; the stimulation of secretory activity in practically all endocrine, exocrine, and neurocrine cells; and the regulation of contraction and relaxation in cardiac and skeletal muscle.

The skeleton is an important reservoir of calcium, serving both to maintain plasma calcium concentrations and to make optimal use of ingested calcium.

It serves both functions mainly by adjusting the balance between bone formation-transfer mineral from blood to bone, and bone resorption-transfer mineral from bone to blood.

In human body, calcium accounts for 2-4% of gross body weight. A 60 g adult body adult female typically contains about 1000-1200 g (25-30 mol) of calcium in her body.

More that 99% of that total is in bones and teeth. About 1 g is in the plasma and extracellular fluid – ECF bathing the cells and 6-8 g in the tissues themselves.

Human health is dependent on homeostasis. When homeostasis is altered, the people can become sick, even die.

In calcium homeostasis, which occurs in early adulthood (about 35 years of age), the amount of calcium deposited in bone is the same as the amount reabsorbed. In the growing child the deposition of calcium increases and occurs in proportion to bone growth. Skeletal turnover, although less rapid during adulthood, continues throughout life an somewhere around the fourth decade, the turnover becomes dominated by bone resorption.

Research indicates a positive calcium balance can occur in the skeleton as a whole for approximately 10 to 15 years after cessation of linear growth. Roughly from age 18 to 35 years, a person can build skeletal massiveness, reaching full skeletal at around 35 years.

Calcium is involved in the function of excitable tissues. Before the heart can ‘beat’, special cells in a region of the heart called the SA node must spontaneously initiate an electrical pulse. Calcium is fundamentally involved in initiating the impulse the SA (sinoatrial) node. This impulse the will stimulates the rest of the heart to contract.

Calcium also involved in the contraction of the heart muscles also the contraction of the skeletal muscles.
Functions of Calcium in Human Body

Essential Minerals

The essential minerals are those that have well defined biochemical roles and must be in the diet of vertebrates for optimum health and productivity.

There are seven minerals known to be essential and that are present in fairly large quantities, are calcium, phosphorus, potassium, sodium, chloride, magnesium and sulfur.

The principal minerals present in micro quantities are iron, copper, cobalt, manganese, zinc, iodine and molybdenum. These minor minerals are needed in amounts less than 100 per day.

Accumulating evidence indicates that selenium, fluoride and chromium are essential elements for mostly species and nickel, silicon, tin, and vanadium are essential for some animals and likely also for man.

The amount needed each for optimal health and productivity is referred to as the dietary requirement.

Essential elements characteristically tend to concentrate in body tissues in a fairly consistent fashion; absorption from the gut and excretion through the kidney, bile, or other intestinal secretions are precisely regulated by body homeostatic mechanisms.

A number of minerals that in minute amounts are essential to body functioning are toxic when accumulated in large amounts. Iron, zinc, and manganese as well as some of the newly detected-essential trace mineral are in this category.

The elements are required for a variety of functions including giving structure at the skeleton, muscle contractions, blood formation, the synthesis of protein and the production of energy.

In order to analyze minerals that are present in biological material the elements must be freed from the organic complexes to which they are bound.

The mineral elements are not homogenously distributed among various types of food is clear: few foods other than dairy products are rich in calcium; sea foods constitute the best sources of iodine and chloride; meats are the most important sources of iron; and protein rich foods comprise the best sources of zinc, copper and selenium.
Essential Minerals