P – Phosphorus is found in igneous rocks at 1,050 ppm; shale at 700 ppm; sandstone at 170 ppm; limestone at 400 ppm; fresh water at 0.005 ppm; sea water at 0.07 ppm; soil at 650 ppm (“fixed” by hydrous oxides of AI and Fe in acid soil). Great and vast reaches of Earth are deficient in P; marine plants at 3,500 ppm; land plants at 2,300 ppm; marine animals at 4,000 to 18,000 ppm; land animals at 17,000 to 44,000 ppm.
Phosphorus is an extremely important essential mineral; however, it gets little or no attention from nutritionists because it is widely available in all foods. Phosphorus is a major structural mineral for bones and teeth, it has more functions in the human than any other mineral including its role as a vital constituent of nucleic acids, activates enzymes, for several steps of the ATP energy cycle; RBC metabolism (a complete discussion of P would require a. discussion of every metabolic function in the body). Second in abundance only to calcium in the human body, it comprises 22 percent of the body’s total mineral content. The human body contains about 800 grams of P (just short of two pounds) of which 700 grams is found in bones and teeth as insoluble calcium phosphate (apatite crystals). The balance of P in the human body is found as biologically active intra and extracellular colloidal P in combination with carbohydrates, lipids, protein and a wide variety of other biologically active organic compounds including the blood’s major buffering system. B-complex vitamins function as coenzymes to intracellular metabolic functions only when combined with R
Phosphorus is part of most proteins and as such becomes problematic (elevated P intake increases Calcium requirements) when “high protein diets” are consumed by aggravating osteoporosis, arthritis, high blood pressure, loose teeth, etc. Phosphorus is present as phytates in cereals and grain flours, therefore, if bread is made from unleavened flours, the phytic acid will complex with Ca, Fe, Zn and other minerals further lowering their absorption rate.
The average adult human dietary intake of P is 1,000 to 1,500 mg/day. In adults and older children, the absorption of metallic P is limited to about three to five percent and as high as eight to 12 percent in infants. Mixed dietary sources of P (chelated forms) may be absorbed at the rate of 40 to 50 %. Optimal absorption of metallic and chelated P occurs when the Ca: P ratio is 1: 1. Colloidal P is absorbed up to 98 %.
Deficiencies of P have long been recognized in livestock but only recently have been deemed important in humans. The widespread, universal and ultimately fatal results of P deficiency are the result of its widespread biological functions, significantly as the result of a decrease in ATP synthesis (complete metabolic energy failure) with associated neuromuscular, skeletal, blood and kidney disease.
Clinical P depletion and resultant low blood P (hypophosphatemia) result from IV administration of glucose or TPN (Total Parenteral Nutrition) without P supplementation, excessive use of antacids, hyperparathyroidism (low calcium/ high phosphate diets are the cause of this one), improper treatment of diabetic acidosis, use of diuretics, sweating during exercise and alcoholism with and without liver disease.
Vegetarians and vegans who do supplement with minerals rarely have P deficiency; however, because of their high phytic acid intake they always have other mineral deficiencies including Ca, Cu, Cr, V. Li and Zn.
Phosphorus is a major mineral nutrient found primarily in bones and teeth. Phosphorus is the most common mineral in the body after calcium and accounts for nearly 1.5 pounds of an adult’s weight. Phosphorus exists in the body as phosphate, an inorganic, negatively charged ion. Phosphate and calcium metabolism is linked. They are withdrawn together from bone to maintain normal blood levels; vitamin D is required for both calcium and phosphate uptake. Calcium phosphate forms hydroxyapatite, the mineral deposit of bones and teeth, which represents 80% of the total phosphorus in the body. The remainder occurs in blood and soft tissues.
In blood, phosphate acts as a buffer to help maintain acid /base balance. The phosphate level in blood is increased by parathyroid hormone from the parathyroid gland and decreased by calcitonin, a hormone from the thyroid gland. The KIDNEY also helps to regulate phosphate. If blood phosphate levels rise, kidneys excrete phosphate; when dietary phosphate is low, they excrete less.
Tissues incorporate phosphate as phospholipids. These relatives of fat form cell membranes and form lipid protein particles to transport fat and cholesterol through the circulation. Phosphate comprises part of the backbone structure of DNA and RNA. These substances store genetic information and control protein synthesis, cell division and growth and maintenance of the body.
Phosphate forms a building block of many coenzymes, enzyme helpers derived from vitamins: niacin, riboflavin, pantothenic acid, thiamin, vitamin B12 and vitamin B6. ATP (adenosine triphosphate) contains phosphate groups in a form representing large amounts of potential energy that can be tapped to drive biosynthetic reactions. The formation and utilization of ATP present extremely important aspects of energy utilization by all life forms.
Requirements
The Recommended Dietary Allowance for phosphorus is 1,000 mg for adults. The standard U.S. diet is phosphate-rich and deficiencies are unlikely. When the ratio of calcium to phosphorus is approximately equal phosphorus uptake is adequate. An excess of dietary phosphorus over calcium can decrease calcium uptake.
People who chronically ingest excessive amounts of antacids, patients with bone fractures, and strict vegetarians eating high-fiber foods grown on phosphorus-depleted soil may become deficient in this mineral. Symptoms include loss of appetite, weakness and pain. Certain bone diseases, rickets in children and osteomalacia in adults, are caused by chronic deficiencies of vitamin D, calcium and phosphorus, or by an imbalance of calcium and phosphorus. Excessive levels of phosphorus can cause low blood calcium, with tetany and convulsions.