Dietary phosphorus.
Phosphorus or dietary phosphorus is an essential mineral. The term  "essential" means that the substance is not produced in the body and must be obtained from dietary sources. The mineral is found in abundance within the human body. Researchers have estimated that the weight of phosphorus can easily be one pound (lb) and quite often, reaches an impressive one percent of the overall body weight. This depends on the person's myoskeletal structure, since nearly 85% of the mineral is concentrated in the bones and teeth and 14% in muscles.
Phosphorus participates in a wide range of biochemical reactions within all cells and tissues. The mineral boosts the action of related enzymes and contributes to the storage and release of any necessary energy for these reactions. Phosphorus is predominantly found in the chemical form of phosphate. Phosphate ester monomers are the base of the nucleic acids DNA and RNA which are responsible for the transmission of genetic information. Phosphorus participates in the structure of the adenosine tri-phosphate (ATP), a high energy molecule needed to store and provide energy for cellular function.
Phospholipid is another biochemical form of phosphorus and it is considered the prominent compound of cell membrane.
Dietary phosphorus plays a key role in formation of teeth and bones, healing, protein synthesis, metabolism of fats and carbohydrates, production of ATP and its precursor creatine phosphate. Phosphorus contributes to formation of cell membrane, muscles contraction, renal function, regularity of the heartbeat and maintenance of nerve system.
Sources of dietary phosphorus.
Meat, poultry, fish, milk and eggs are the main food sources. Phosphorus is contained in smaller amounts in cereals, seeds, legumes, carbonated soft drinks, alcoholic beverages, brewer's yeast, fruits and vegetables. It has to be mentioned that whole-grain flour and relevant products contain larger amounts of phosphorus than their refined counterparts. However, the mineral exists in the form of phytin, which is not absorbable by the intestinal track in humans.
The main principal is that a meal, which provides adequate amounts of calcium and protein, contains adequate amounts of phosphorus as well. There is a widespread perception in the scientific community that high phosphorus or protein intake may reduce the stores of calcium in human body. However, this is a controversial issue, since a number of studies have not given such evidence. On the contrary, in elderly people a low protein and phosphorus diet may have adverse impact on calcium balance.
Phosphorus deficiency and toxicity.
In general, phosphorus deficiency is quite rare, since it is readily available in foods and it is easily absorbed within the intestinal track. For this reason, supplementation for phosphorus is hardly needed. However, conditions, such as gastrointestinal problems, anorexia nervosa, bulimia, kidney dysfunction and diabetes, may either inhibit adequate absorption or they may increase the excretion of the mineral and can lead to phosphorus deficiency.
Signs and symptoms of phosphorus deficiency include muscle weakness, fatigue, anorexia, limb numbness or tingling, pain in bones, anemia, irregular breathing, impaired reflexes, anxiety, tremors, disorientation and confusion.
Toxicity is not common, since kidneys can easily maintain phosphorus balance. In any excess state, phosphorus is excreted in urine. However, in cases of prolonged periods of excessive phosphorus intake, calcium stores may be depleted.
Recommendations for dietary phosphorus.
According to USDA recommendations, the allowances of dietary phosphorus intake are the following:
First year: 100 to 275mg
One to three years: 460mg
Four to eight years: 500mg
Nine to eighteen years: 1,250mg
Adults, in general, and pregnant or nursing women: 700mg.
The recommended dietary allowance (RDA) for phosphorous is 1,000mg per day. |
