What is Phosphorus & What Does it Do?

Phosphorus is a mineral found in rocks and soil that makes its way into our bodies through the food we eat.  It plays major roles in energy production, our cell membranes, acid-base regulation in our blood and tissues, cell signaling, bone mineralization, and the physical structure of our genetic code. (1)

About 85% of the phosphorus in our body is found in bones and teeth.  A significant remainder is used to  create the phospholipid bilayer of cell membranes and the sugar backbone of our DNA and RNA. (1)  Phosphorylation (the addition of a phosphate group) is also a key step in transmitting messages from one part of our bodies to another.  Phosphorus also helps regulate the delivery of oxygen to our tissues from our blood cells.  Phosphorus is everywhere in the body doing many different jobs!

Outside of our bodies, phosphorus is used in the production of ammunition, fertilizers, food additives, smoke bombs, and cleaning supplies.  In the past, it was also used in fireworks. (2)  You can see how this mineral is associated with explosive energy!

Phosphorus and Biological Energy: 

Due to its highly reactive nature, phosphorus is only found combined with other elements that stabilize it and keep it from exploding when it encounters oxygen. (2)  This high reactivity is used in living things to create ATP (Adenosine triphosphate) - molecular energy.  ATP has three phosphate groups attached to an adenosine molecule.  The last of these bonds, between the second and third phosphate group, takes a lot of energy to make.  When that bond is broken, that energy is released.

Where are these bonds created?  The mitochondria - the powerhouse of the cell.  When glucose (blood sugar) enters our cells, it is taken to the mitochondria where it is broken down into water, carbon dioxide, and molecules that move electrons.  Those electrons travel through several different molecules, known as the electron transport chain, that acts like a power line moving electricity (electrons) along.  In the final step of this process those electrons are used to spin a molecule called ATP synthase to create that high energy bond in ATP.  If you are interested in going deeper into this topic, this video is a good one!

We can think of this process as the reverse of photosynthesis - where energy (sunlight) is combined with water and carbon dioxide to make glucose.  This time, we are turning glucose into energy, water, and carbon dioxide. 

You may remember that this process is necessary for life, but it also produces dangerous free radicals that can lead to oxidative stress, cell damage, and inflammation.  Lucky for us, antioxidants like vitamin C, vitamin E, glutathione, and flavonoids are there to soak up free radicals and prevent this damage! 

Phosphorus and Acid/Base Balance: 

For bodies to run properly, we need our blood and tissues to stay at a pH of 7.40. (3)  We rely on molecules that can release hydrogen or hydroxide ions to adjust our pH up or down; these molecules are known as buffers.  Phosphorus acts as one of our most important buffers.  When you hear people talk about foods that “make you” more acidic or alkaline, you can rest assured that phosphorus and other buffers make this a non-issue.  

Do take care though, as eating acidic foods or drinking acidic substances (such as sodas and bottled waters) can damage the enamel of your teeth over the long term. (4)  Also, ingesting baking soda or other alkaline agents can reduce the acidity of your stomach, interfering with digestion and leading to indigestion and nutrient deficiencies over the long run.  Additionally, purposefully ingesting baking soda can lead to increased gas - remember baking soda and vinegar volcanoes?  

Remember, we need our stomach acid!  If you suffer from heartburn, the problem is rarely too much stomach acid and is more often related to what you are eating, how you are eating, or even low stomach acid levels!

Phosphorus Deficiency: 

Luckily, phosphorus deficiency is uncommon, due to our ability to recycle phosphorus through our kidneys.  However, it can occur in some situations:  (1)

• Severe alcoholism

• Recovery from diabetic ketoacidosis

• Respiratory alkalosis (increased carbon dioxide in the blood due to hyperventilation) 

• Rare genetic disorders that inhibit the kidneys from reabsorbing phosphorus

• Near-total starvation 

Signs and Symptoms of Phosphorus Deficiency:

Low phosphorus levels, hypophosphatemia, causes the following symptoms: (1), (5)

• Loss of appetite

• Muscle weakness

• Bone fragility

• Numbness in the extremities

• Rickets in children

• Anemia

• Increased risk of infection

• Confusion

• Ataxia

Those at increased risk of developing deficiency include preterm newborns, those with rare genetic phosphorus metabolism deficiencies, those struggling with alcoholism, those with uncontrolled diabetes, and those suffering from severe malnutrition. (5)

Where to Find Phosphorus: 

Phosphorus is found in most foods.  It is also found in most processed foods due to its use in food additives.  The phosphorus found in plant sources is about 50% less bioavailable than that found in animal sources or food additives; however, a healthy plant-based diet still contains enough phosphorus for healthy functioning. (1)

Daily Intake:

The RDA for phosphorus is highest during the ages of 9-18 where 1250 mg is required daily.  During adulthood that number falls to 700 mg daily.  There is no difference in requirement due to biological sex, pregnancy status, or whether one is breastfeeding. (1)

Toxicity:

You guessed it, too much of a good thing isn’t a good thing.  High levels of phosphorus are associated with kidney disease, low parathyroid function, and increased absorption of phosphate salts taken orally or through enemas.  Elevated phosphate levels lead to rapid progression of kidney disease and overall deterioration of health. (1)

Puzzlingly, individuals with high-normal levels of phosphorus in their blood also tend to have a higher risk of developing heart disease (enlarged left ventricle or heart failure) and kidney disease (regardless of their current kidney health).  The current hypothesis is higher phosphorus levels in the blood may lead to calcification of the blood vessels around the heart and in the kidneys. (1)

Due to this, a tolerable upper limit (UL) of 4,000 mg has been set for adults up to 70 years of age and 3,000 mg for those over 70.  Studies have shown that healthy adults with phosphorus intakes of 8,000 mg or more daily have higher rates of death from all causes. (1).  This is yet another reason to avoid processed foods and opt for more plant-based foods!

Prevention and Treatment of Disease:

Phosphorus is not known to have a role in the prevention or treatment of disease. 

Medication and Nutrient Interactions:

Antacids can bind to phosphorus and, with extended use, may lead to low phosphorus levels. (5)  Hormone replacement therapy in postmenopausal women can also lead to excessive phosphorous excretion and low levels. (1)

Laxatives containing sodium phosphate can cause high phosphorus levels when used above the recommended dose. (5)  Proton pump inhibitors can reduce the effectiveness of phosphate-binders in patients with kidney disease leading to increased phosphate levels. (1)  High doses of 1,25-dihydroxyvitamin D (DVHD) can also lead to high phosphate levels. (1)

Lastly, the combination of potassium supplements or potassium sparing diuretics with phosphorus supplements can lead to excessively high levels of potassium in the blood (hyperkalemia) which can lead to life threatening heart arrhythmias. (1)

Applications:

This week, I hope you walk away with these key points: 

1. Phosphorus is important for many functions in our body and is found pretty much everywhere.

2. Low phosphorus levels are harmful but rare.

3. High phosphorus levels can lead to heart and kidney disease.

4. The high bioavailability of phosphorus in processed foods and animal products and reduced bioavailability in plants make a whole-food-plant-based diet even more important for overall health. 

5. You don’t need to worry about “acidic” vs “alkaline foods” ; our bodies use buffers like phosphorus to keep our blood at a steady pH of 7.40.

Next week: 

Next week we will focus on potassium.  It’s found in far more foods than bananas, and along with calcium and magnesium, it can be quite helpful for muscle cramps and spasms.

To our health!

References: 

1. Higdon, J, “Phosphorus” Linus Pauling Institute, 2001; last update: 2014; accessed January 20, 2022; https://lpi.oregonstate.edu/mic/minerals/phosphorus

2. National Center for Biotechnology Information (2022). PubChem Compound Summary for CID 5462309, Phosphorus. Retrieved January 27, 2022 from https://pubchem.ncbi.nlm.nih.gov/compound/Phosphorus.

3. Peter Constable, CHAPTER 111 - Clinical Acid-Base Chemistry, Editor(s): Claudio Ronco, Rinaldo Bellomo, John A. Kellum, Critical Care Nephrology (Second Edition), W.B. Saunders, 2009, Pages 581-586, ISBN 9781416042525, https://doi.org/10.1016/B978-1-4160-4252-5.50116-7. 

4. Zimmer, S., Kirchner, G., Bizhang, M., & Benedix, M. (2015). Influence of various acidic beverages on tooth erosion. Evaluation by a new method. PloS one, 10(6), e0129462. https://doi.org/10.1371/journal.pone.0129462

5. National Institutes of Health, “Phosphorus- Fact Sheet for Health Professionals”, updated 3-26-2021, https://ods.od.nih.gov/factsheets/Phosphorus-HealthProfessional/#h5