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Mineral Nutrient :: Phosphorus


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Content Below: What is Phosphorus · Benefits · Deficiency Signs · Foods · Supplements · RDA · Toxicity

What is Phosphorus ?
Phosphorus is an essential macro-mineral.  It is one of the most abundant minerals in the body.  It normally makes up about 1% of total body weight.

Phosphorus is required for normal functioning of every cell in the body but most of it, approximately 85%, is bound with calcium to form bones and teeth.  Calcium phosphate is the major mineral component of bones.

Our bodies need a balance of calcium, phosphorus, and magnesium.  If this balance is not maintained, our health is affected.  Phosphorus is absorbed in the small intestine, and excess is excreted by the kidneys.

How Phosphorus Benefits Health
Phosphorus is needed for most of the bio-chemical processes in the body, such as cell growth and conversion of food to the energy that fuels every action and function of the body.

Recent studies show that calcium needs phosphorus to build strong bones. Calcium alone is insufficient.  Taking calcium supplements on its own would therefore be not much use if there is not enough phosphorus in the body.

:: Phosphorus Benefits & Functions
1. main role is in binding with calcium to form healthy bones and teeth
2. may be helpful in cases of vitamin D resistant rickets
3. needed for metabolism of carbohydrates and fats to produce energy
4. important for production of ATP (Adenosine Tri Phosphate), the molecule that the body uses to carry energy
5. required for synthesis of protein for growth and repair of cells and tissues, including nucleic acids (DNA and RNA)
6. needed to make phospholipids, such as phosphatidylcholine, that are structural components of cell membranes
7. helps the body utilize the B-complex vitamins
8. needed for heart muscle contraction and to regulate heartbeat
9. supports proper muscle and nerve function
10. may help alleviate multiple sclerosis
11. helps maintain normal acid-base (pH) balance in the body by acting as an important buffer
12. maintains calcium balance and helps prevent hypercalcemia (high blood calcium levels)
13. maintains kidney function
14. potassium and sodium phosphate taken orally are FDA-approved for use to help prevent or treat calcium-based kidney stones in people with hypercalciuria (high urine calcium levels) or those with calcium oxalate stones; avoid if stones are phosphate-based
15. FDA-approved for treating occasional constipation, and to restore bowel function after surgery


Phosphorus Deficiency Symptoms and Causes
Unusually low blood phosphate levels is called hypophosphatemia.  Severe forms of it can result in death.  However a deficiency of phosphorus is rare as it is present in most foods.

It happens mainly in cases of anorexia or near-starvation. Other people at risk include alcoholics and diabetics.  A diet high in fructose, especially if it is low in magnesium, increases loss of phosphorus in urine and depletes the body of it as well.

Also, certain medications, for example antacids with calcium or magnesium or aluminium, can bind with phosphorus in the intestine, and interfere with its absorption.  Some anti-convulsants may lower phosphate levels too.

Chronic use of these medications increases the risk of hypophosphatemia. It is best to separate consumption of high phosphorus foods from such medication by at least an hour.

Deficiency is unusual, but in the unlikely event that it occurs, a number of phosphorus deficiency symptoms can be identified.

:: Phosphorus Deficiency Symptoms
1. poor bone formation and growth
2. impaired bone mineralization that causes rickets in children (softening of bones that result in skeletal problems such as knock-knees, bowed legs, spinal curvature, narrowed chest, and soft skull bones)
3. osteomalacia (adult rickets) that causes bones to be soft and prone to fractures, and symptomized by deformities in the spine and limbs, and rheumatic or arthritic-like pain
4. numbness and tingling of the extremities (hands and feet)
5. difficulty walking
6. increased susceptibility to infection
7. fatigue or muscle weakness
8. anemia
9. loss of appetite and changes to weight


Phosphorus Foods
Many foods contain phosphorus naturally.  Processed food and soft drinks are high in added phosphates but these are in a form best avoided as they appear to cause de-calcification of bones.

Phosphorus in seeds like nuts, peas, beans and grains, is in a form known as phytic acid or phytate which hinders its absorbability so that only about half the phosphorus can be taken in by the body.

Foods high in phosphorus are · cheese · milk · meat · legumes (adzuki beans, chickpeas or garbanzo beans, yellow beans, lentils) · whole grains (wheat, oats, millet, quinoa, brown rice, corn, rye).

Moderately high phosphorus foods include · asparagus · brewer's yeast · dried fruit · eggs · fish · garlic · nuts (almonds, brazil nuts, cashews, pine nuts, walnuts) · pumpkin, sesame, and sunflower seeds · rice bran.


Phosphorus Supplements
Taking vitamins and minerals in their correct balance is vital to the proper functioning of all vitamins.  They work synergistically, which means that the effectiveness of any one nutrient requires, or is enhanced, sometimes dramatically, by the presence of certain other nutrients.

For this reason, if you are looking to take supplements for maintenance of optimal health, the recommended approach is to take a multi-vitamin that has the proper balance of all the necessary nutrients your body needs.

For a list of reputable top ranked vitamin and mineral supplements chosen in an independent supplement review, see Best Multivitamin Supplements. Many of these are manufactured to pharmaceutical or nutraceutical GMP compliance, which is the highest multivitamin standard possible.

Keep in mind, however, that while mineral supplements are useful to plug nutritional gaps that are almost inevitable in modern diets, and to ensure we get optimal doses of nutrients, they are no substitute for a good diet. Instead, use them to complement a healthy diet and lifestyle.


Phosphorus RDA (Recommended Dietary Allowance)
The Food & Nutrition Board of the Institute of Medicine, National Academy of Sciences, in their 1997-2001 collaboration between the US and Canada, set the daily Adequate Intake (AI) of Phosphorus as follows.

Life Stage | Gender Phosphorus Dosage | Day
Infants 0-6 mths 100* mg
Infants 7-12 mths 275* mg
Children 1-3 yrs 460 mg
Children 4-8 yrs 500 mg
Girls 9-13 Yrs 1250 mg
Boys 9-13 Yrs 1250 mg
Females 14-18 Yrs 1250 mg
Males 14-18 Yrs 1250 mg
Females 19-50 Yrs 700 mg
Males 19-50 Yrs 700 mg
Females older than 50 Yrs 700 mg
Males older than 50 Yrs 700 mg
Pregnant Women 14-18 Yrs 1250 mg
Pregnant Women 19-50 Yrs 700 mg
Lactating Mothers 14-18 Yrs 1250 mg
Lactating Mothers 19-50 Yrs 700 mg

These dosages are the minimum required per day to ward off deficiency. In therapeutic use of this nutrient, dosage is increased as necessary for the ailment, keeping in mind Phosphorus toxicity levels.


1 µg = 1 mcg = 1 microgram = 1/1,000,000 of a gram
1 mg = 1 milligram = 1/1,000 of a gram

* Indicates AI figures based on Dietary Reference Intake (DRI) figures


Phosphorus Overdose Symptoms, Toxicity Level & Side Effects
Excess phosphorus can cause hyperphosphatemia or high blood phosphate levels.

A common reason for this is over-consumption of foods high in phosphorus, such as canned, processed, or fast foods, or soft drinks.  Many of these have phosphates added to extend shelf life or enhance flavors, especially in baked products, cheeses, meats, and drinks.

A deficiency in calcium or magnesium may lead to excess blood phosphate. At the same time, high levels of phosphorus interfere with calcium uptake, which, if coupled with a low calcium diet over a long period, increases the risks of bone density loss, hypertension, and bowel cancer.

Hyperphosphatemia can also occur in people with impaired kidney function. Healthy kidneys remove excess phosphorus from the blood.  People with chronic kidney diseases are unable to get rid of extra phosphorus, and are at risk of heart and bone diseases, and even death.

As noted in the Journal of the American Medical Association, such patients need to avoid foods high in phosphorus (see Food Sources), and especially fast foods and soft drinks.

Too much phosphorus can cause serious electrolyte imbalances.  It draws calcium out of bones and weakens them, leading to brittle bones.  Excess calcium and phosphorus together may result in harmful calcium deposits or calcification, in soft tissues such as the lungs, heart, muscles, eyes, blood vessels, and especially the kidneys.

To avoid such adverse effects, the Food & Nutrition Board of the Institute of Medicine has set Tolerable Upper Intake Levels (ULs) for phosphorus as listed in the table below. The lower UL for those over 70 years old reflects the possibility of lower kidney function.

Tolerable Upper Intake Levels (UL) for Phosphorus per Day
Age Male Female
0 to 12 months *ND *ND
1 to 8 years 3 g 3 g
9 to 70 years 4 g 4 g
Above 70 years 3 g 3 g
Pregnant Women   3.5 g
Lactating Mothers   4 g
*ND : Not determinable.  Intake should be from food/milk only.

These ULs do not apply to people with severely impaired kidney function or other health conditions that increase their risk of phosphorus toxicity, who should follow their doctors' guidelines instead.

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1. Institute of Medicine, Food and Nutrition Board. Dietary reference intakes for calcium, phosphorous, magnesium, vitamin D, and fluoride. Washington DC: National Academy Press; 1997.

2. U.S. National Libary of Medicine [NLM] & National Institutes of Health [NIH]: MedlinePlus. NLM-NIH home page. <http://www.nlm.nih.gov/medlineplus>. Use the built-in search function to find specific data. Accessed 2009 March – June.

3. Oregon State University, Linus Pauling Institute. Micronutrient Information Center [MIC]: Micronutrient research for optimum health. MIC home page. <http://lpi.oregonstate.edu/infocenter>. Accessed 2009 May.

4. Balch JF, Balch PA. Prescription for nutritional healing: A practical A-Z reference to drug-free remedies using vitamins, minerals, herbs & food supplements. Garden City Park, New York: Avery Publishing; 1990.

5. Ulene A. Dr. Art Ulene's complete guide to vitamins, minerals and herbs. New York, NY: Avery Publishing; 2000.

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