Phosphorus in the human diet is closely related to calcium, to the point that a deficiency of one creates a problem in the utilization of the other.
What is Phosphorus
Phosphorus is a mineral essential for the proper functioning of cells and the body. It makes up 1% of body weight and, together with calcium, is the most important mineral for the normal construction of bones and keeping them in good condition.
Phosphorus is found in all the cells of the body, is involved in almost all reactions and represents the most vital mineral element for the life of the individual.
Contributes to the metabolism of carbohydrates, proteins and fats
Phosphorus contributes to the metabolism of carbohydrates, proteins and fats for energy production, which depends on phosphorylated compounds such as adenosine triphosphate (ATP) and creatine phosphate.
Nucleic acids (DNA & RNA), responsible for storing and transmitting genetic information, are phosphorus-containing macromolecules in chain form. The activation of a large number of enzymes, hormones and molecules charged with transmitting messages in the body depends on phosphorylation.
Maintains the pH balance in the blood
Phosphorus also helps maintain the necessary acid-base balance (pH) in the blood as it acts as a buffer in the body. In addition, 2,3-diphosphoglycerate molecules that contain phosphorus bind hemoglobin in red blood cells and affect the release of oxygen to the body’s tissues.
Essential for the proper growth and maintenance of bones
It is essential for the proper growth and maintenance of bones, connective tissue and teeth. Phosphorus helps in the proper functioning of the heart, kidneys and nervous system.
Symptoms of deficiency are similar to those in case of calcium deficiency, such as loss of bone mass, rickets, osteomalacia and muscle weakness.
Inadequate phosphorus intake results in abnormally low serum phosphorus levels in the blood (hypophosphatemia). Because phosphorus is found in abundance in food, it is rarely deficient due to diet and the only time it occurs is in the latter stages of starvation.
However, deficiency is likely to occur in people who have been on medication for a long time with antacid preparations, which prevent its absorption.
Also hypophosphatemia is likely to occur in alcoholics, diabetics recovering after an episode of ketone oxidation & in anorexic or starving individuals after refeeding diets rich in calories but low in phosphorus.
The main contributions of phosphorus are:
Recommended Daily Intake
The recommended daily intake set by the European Union is 700mg/day. The utilization of phosphorus as well as calcium & magnesium is carried out with the help of vitamin D.
Phosphorous Side Effects (Toxicity)
The most dangerous consequence of an abnormally high level of phosphorus in the blood (hyperphosphatemia) is calcification of non-skeletal tissues, especially the kidneys.
Because the kidneys are very efficient at eliminating excess phosphorus from the circulation, diet-induced hyperphosphatemia is usually only a problem in people with kidney damage (end-stage kidney disease) or hypoparathyroidism.
When kidney function is only 20% of normal it can cause hyperphosphatemia. Cases of hyperphosphatemia have also been observed due to increased absorption in the intestine of oral phosphate, but also due to phosphorus absorption using enemas.
To avoid hyperphosphatemia, the Food & Nutrition Committee has set a tolerable upper limit for phosphorus intake in healthy individuals.
Phosphorous Foods and Sources
Phosphorus is found in almost all foods because it is an essential component for every living organism.
Dairy products and fish, meat & eggs are particularly rich in phosphorus. Phosphorus is also a component of many polyphosphate food additives and can be found in many soft drinks in the form of phosphoric acid.
It is also found in the form of phytic acid in all grains (beans, peas, cereals & nuts).
Rich sources of phosphorus are:
Phosphorus is absorbed in the intestine (small intestine) and if it is bound in the food, it is separated from the phosphate compound and then absorbed as a mineral.
Its absorption depends on many factors such as: The Ca/P (calcium/phosphorus) ratio, the PH of the intestinal contents, lactose intake, dietary intakes of Ca -P -vitamin D, iron, aluminum, manganese and fat intake and is particularly dependent on the dietary content of each of these elements.
From the blood, after absorption, phosphorus is transported to the bones and teeth. From these, according to metabolic needs, it is, like calcium, carried into the blood.
Its levels in the blood are related to the action of parathyroid hormone and calcitonin and are inversely related to calcium levels.
The main route of phosphorus removal is the urine, where the renal tubules excrete phosphorus in an inverse relationship to its content in the blood or diet.
In a normal diet, excretion is 0.6-1.0 g/day.