encyclopedia

Phosphorus

Natural Sources:
Asparagus, bran, brewer’s yeast, corn, dairy products, dried fruit, garlic, legumes, nuts, sesame, sunflower and pumpkin seeds, whole grain breads and cereals and other foods are good sources of phosphorus.

Forms:
Standardized multivitamin pills containing phosphorus in capsules, tablets and liquid supplements.

Therapeutic Uses:
Aging Disorders

Anemia

Anorexia nervosa

Anxiety

Arthritis

Bone Health

Bone Pain

Breathing Disorders

Chronic Fatigue Syndrome

Dry Skin

Energy Loss

Fatigue

Growth Impairment

Heart Health Maintenance

Heart Palpitations and Fluctuations

Irregular Breathing

Irritability

Lethargy

Mineral Deficiency (RDI=1,500mg/day)

Muscular Fatigue and Weakness

Nervous System Health

Numbness

Osteomalacia (rickets)

Osteoporosis

Rickets

Rheumatoid Arthritis

Skin Disorders

Skin Sensitivity

Vascular Disorders

Weight Changes

Overview:

Phosphorus is a waxy white solid metallic element that is an important component of many organic compounds. The word phosphorus comes from the Greek word, phosphoros, meaning light bearing (also the ancient name for the planet Venus when appearing before sunrise). Phosphorus never occurs alone in nature but is widely available in combination with other minerals. Phosphorus is an essential ingredient of all cell protoplasm, nervous tissue, and bones. Phosphorus is one of the most abundant elements in the human body. The average body contains about 1 to 1.5 pounds of phosphorus, second only to calcium as the most abundant mineral. Most phosphorus in the body is complexed with oxygen as phosphate (PO4). About 85% of the roughly 500 to 700 grams of phosphate in the body is contained in bones and teeth, where it is an important constituent of hydroxyapatite, a crystalline compound that gives bones strength. The other 15% is not only active in many metabolic processes but is also found in every cell of the body. Phosphate is an integral component of several organic compounds, including nucleic acids and the phospholipids of cell membranes. In soft tissues, phosphate is mainly found in the intracellular compartment. Phosphates are also required for aerobic and anaerobic energy metabolism. Overall, phosphorus is critical for many bodily functions including the conversion of food to energy, maintenance of pH balance in the blood, utilization of vitamins, absorption of nutrients, growth, and maintenance and repair of all body tissues. The typical American diet contains about 800 to 1500 mg of phosphate daily. Like calcium, gastrointestinal phosphate absorption is enhanced by vitamin D. Certain diseases cause phosphate depletion of the body, usually resulting in retention of phosphate by the kidneys. Bone phosphate serves as a reservoir, which can buffer changes in plasma and intracellular phosphate.

Chemistry:
Phosphorus, a waxy white solid metallic element in its pure form, was discovered in 1669 by a chemist named Brand who isolated it from urine. It is very poisonous in its pure form, with 50 mg constituting an approximate fatal dose. Phosphorus never occurs alone in nature but is widely available in combination with other minerals. Phosphate rock, which contains the mineral apatite, an impure tri-calcium phosphate, is an important source of the element. Large deposits are found in Russia, Morocco, Florida, Tennessee, Utah, Idaho, and elsewhere.

Suggested Amount:

The Recommended Daily Allowance for phosphorus (taken as phosphate) is between 700 to 1,250 mg daily for adults, depending upon age as follows:

Ages 9-18 years: 1,250mg daily

Ages 19 and older: 700mg daily

The RDA for phosphorus for children aged 1-3 is 460mg daily and from 4-8 years is 500mg. Infants younger than 6 months require 100mg daily and infants from 6 months to a year require at least 275mg daily. The upper limit for intake for children and adults is approximately 3000 to 4000 mg (3-4 grams) daily. One quart of low-fat or skim milk provides 1 gram of phosphate. Note: For proper phosphorus absorption and utilization by the body, several cofactors are required in balanced amounts including: vitamin D, calcium and magnesium. The ratio of phosphorus to calcium in the diet should be about 2 to 1.

Drug Interactions:
Taking calcium supplements without taking a balanced supply of phosphorus at the same time may cause significant phosphorus deficiency due to the formation of calcium phosphate complexes within the system that are then excreted. This problem can be avoided by taking calcium phosphate or by assuring an adequate phosphorus supply within the diet.

Contraindications:
None known.

Side Effects:
There are no side effects known for phosphorus taken in normal dosages. However, in large dosages, sources of sodium and potassium phosphate are often poorly tolerated due to diarrhea.

References:

Carvalho NF, Kenney RD, Carrington PH, Hall DE. 2001. Severe nutritional deficiencies in toddlers resulting from health food milk alternatives. Pediatrics. 2001 Apr; 107(4): E46.

Heaney, Robert P. and B. E. C. Nordin 2002. Calcium Effects on Phosphorus Absorption: Implications for the Prevention and Co-Therapy of Osteoporosis J Am Coll Nutr 2002 21: 239-244.

Ksiazyk J. 2000. [Current views on requirements for vitamin D, calcium and phosphorus, particularly in formula fed infants]. Med Wieku Rozwoj. 2000 Oct-Dec; 4(4): 423-30. Polish.

Rodriguez Portales JA. 2001.[Hypovitaminosis D in postmenopausal women with low bone mineral density]. Rev Med Chil. 2001 Aug; 129(8): 849-52. Spanish.

Sasidharan PK, Rajeev E, Vijayakumari V. 2002. Tuberculosis and vitamin D deficiency. J Assoc Physicians India. 2002 Apr; 50: 554-8.

Additional Information:

Cofactors Needed for Absorption:

Just as vitamin D is required for proper calcium absorption, it is also required for proper phosphorus absorption. The Food and Nutrition Board of the National Academy of Sciences in Washington, DC, has issued several reports to update the Recommended Daily Allowances (RDA’s) for vitamins and minerals. They have developed Dietary Reference Intakes (DRI’s) as a comprehensive effort to include current concepts about the role of nutrients and food components in long-term health, going beyond deficiency diseases. The latest report stresses the benefits of a high calcium diet together with balanced uptake of calcium’s related nutrients: magnesium, phosphorus and vitamin D.

Increased Calcium Intake May Lead to Phosphorus Deficiency:

A study published in the June issue of the Journal of the American College of Nutrition warns that increasing calcium intake without increasing phosphorus consumption could prove detrimental to bone health. The recommended daily allowance (RDA) for phosphorus, which is found in good amounts in dairy, meat and fish, is 700 mg for adults, and the RDA for calcium is 1,000 mg. Scientists from Creighton University, in cooperation with researchers from the Institute of Medical and Veterinary Science in Adelaide, South Australia analyzed two data sets: 1) 543 studies of healthy women (aged 35 to 65) and 2) 93 studies of men and women (aged 19 to 78).

The analysis of data in these studies found that each .5 g increase in calcium intake decreased phosphorus absorption by .166 g, leading to the potential for phosphorus deficiency to develop. In nature, calcium generally always binds to phosphorus so this finding is not surprising.

According to Robert P. Heaney, M.D., lead researcher from Creighton University, in a news release from the National Fluid Milk Processor Promotion Board, “Our study found that increasing the amount of calcium consumed without increasing phosphorus intake will lower phosphorus absorption. Unless your intake of phosphorus is generous, the ratio of calcium to phosphorus is very important to ensure that you get enough of bone minerals, and this is particularly critical for older adults receiving treatment for osteoporosis.”

Researchers note that phosphorus deficiencies can occur with the use of calcium supplements and fortified foods consisting of non-phosphate calcium salts. According to Machelle Seibel, M.D., medical director for Waltham, Mass.-based Inverness Medical Innovations Inc., phosphorus is required to merge calcium into bone. “This typically takes place in the intestinal tract. Without enough phosphorus in their systems, the millions of American women taking over-the-counter calcium supplements may be robbing their bodies’ natural store of phosphorus in order to digest the calcium they take.” To address this problem, Inverness has begun manufacturing a product called Posture-D, which contains calcium phosphate.

Phosphorus Deficieny Symptoms:

Low phosphorus (hypophosphatemia) is seen in approximately 2% of hospitalized patients, but is more prevalent in certain populations (i.e. alcoholics, in whom it is seen in up to 10% of hospitalized patients). Acute cases of low phosphorus are often seen in the recovery phase of diabetic ketoacidosis, acute alcoholism, and severe burns. Low phosphorus may also occur with patients receiving total intravenous nutrition and in severe chronic respiratory problems.

Although low phosphorus usually has no symptoms, anorexia, muscle weakness, and osteomalacia (rickets) can occur in cases of severe chronic depletion. Serious neuromuscular disturbances may also occur, including progressive encephalopathy, coma, and death. Blood disturbances from severe phosphorus deficiency include hemolytic anemia, decreased release of oxygen from hemoglobin, and impaired leukocyte and platelet function.

Current views on requirements for vitamin D, calcium and phosphorus, particularly in formula fed infants (Abstract from Medline):

Calcium (Ca) and phosphorus (P) absorption depends on vitamin D. Vitamin deficiency in children results in rickets and osteoporosis in adults. Prematurely born infants are at risk of osteopenia and rickets. Skin synthesis of vitamin D can obtain the level of 10 000 IU (250 ug) when the whole body is exposed to the sun. Recent opinion on vitamin D requirement establishes the level of more than 80 nmol/L of 25(OH)D. There are no recommendations for children but it seems that due to the risk of skin cancer, exposure to the sun in children will be limited and as a result higher dose of vitamin D will be needed. Calcium and phosphorus are the most common minerals of the human body. Calcium concentration in human milk is not related to the intake. Calcium intake of calcium in premature infants is 70-140 mg/100 kcal. Phosphorus content in breast milk, even as low as 15 mg%, can maintain the optimal Ca/P ratio of 2/1. Prolonged breast feeding without additional Ca and P, may result in reduced bone mineralisation. Higher content of calcium in infant formula in comparison to human milk is due to the fact that Ca absorption from breast milk is 60% in comparison to 40% absorption from the formula.

Severe nutritional deficiencies in toddlers resulting from health food milk alternatives (Abstract from Medline):

It is widely appreciated that health food beverages are not appropriate for infants. Because of continued growth, children beyond infancy remain susceptible to nutritional disorders. We report on 2 cases of severe nutritional deficiency caused by consumption of health food beverages. In both cases, the parents were well-educated, appeared conscientious, and their children received regular medical care. Diagnoses were delayed by a low index of suspicion. In addition, nutritional deficiencies are uncommon in the United States and as a result, US physicians may be unfamiliar with their clinical features. Case 1, a 22-month-old male child, was admitted with severe kwashiorkor. He was breastfed until 13 months of age. Because of a history of chronic eczema and perceived milk intolerance, he was started on a rice beverage after weaning. On average, he consumed 1.5 L of this drink daily. Intake of solid foods was very poor. As this rice beverage, which was fallaciously referred to as rice milk, is extremely low in protein content, the resulting daily protein intake of 0.3 g/kg/day was only 25% of the recommended dietary allowance. In contrast, caloric intake was 72% of the recommended energy intake, so the dietary protein to energy ratio was very low. A photograph of the patient after admission illustrates the typical features of kwashiorkor: generalized edema, hyperpigmented and hypopigmented skin lesions, abdominal distention, irritability, and thin, sparse hair. Because of fluid retention, the weight was on the 10th percentile and he had a rotund sugar baby appearance. Laboratory evaluation was remarkable for a serum albumin of 1.0 g/dL (10 g/L), urea nitrogen