Phosphoric acid is a common ingredient found in many processed foods and beverages. Manufacturers use it to enhance taste and extend shelf life.

What Is Phosphoric Acid?

According to the National Institute for Occupational Safety and Health (NIOSH), phosphoric acid is a clear, odorless crystalline substance. To use it in food and drink products, it’s typically diluted with water.

In soft drinks, phosphoric acid adds a tangy, sharp flavor and helps prevent the growth of mold and bacteria, which thrive in sugary environments. It’s also the main contributor to the acidic profile of most sodas.

Phosphoric acid is derived from phosphorus—a naturally occurring mineral present in many foods. Phosphorus works together with calcium to help build strong bones and teeth, according to the National Institutes of Health (NIH). It also plays a vital role in energy storage and kidney function.

The body uses phosphorus to help muscles recover after strenuous activity and to support growth. It is essential for producing DNA and RNA—the molecules that carry genetic information.

To create phosphoric acid, phosphorus undergoes a chemical process that first converts it into phosphorus pentoxide, which is then further processed into its acid form.

Possible Health Risks

In today’s diets, having too much phosphorus is more common than having too little. Because phosphorus occurs naturally in many foods and is also widely added to processed products, most people already get more than the necessary amount.

While phosphorus is essential, excessive intake can pose health concerns. Research has linked high phosphorus consumption with an increased risk of heart disease and osteoporosis. Calcium and phosphorus must be in balance for optimal bone health. An overload of phosphorus can reduce calcium levels in the body, leading to bone demineralization.

It may also interfere with the absorption of other essential nutrients like magnesium, iron, and zinc.

For example, studies have associated high soda consumption with greater risk of bone fractures. One observational study found that people who consumed soda every day were twice as likely to experience a broken bone.

The kidneys are responsible for filtering out excess phosphorus from the bloodstream. People with chronic kidney disease often struggle to eliminate excess phosphorus, making it important for them to monitor their phosphorus intake closely.

It’s also worth noting that pure phosphoric acid, in industrial form, can be hazardous. Contact with the chemical or its fumes can irritate the eyes, skin, and respiratory tract.

Is Phosphoric Acid Safe in Moderation?

The recommended daily phosphorus intake for healthy adults is 700 milligrams. This amount is typically met through a balanced diet that includes natural sources like meat, dairy, legumes, eggs, and fish.

Because many of these protein-rich foods naturally contain phosphorus, the extra phosphorus from processed foods and beverages—like soda—often pushes daily intake beyond the body’s actual needs.

The form of phosphorus added to processed foods is also more easily absorbed, which further contributes to elevated phosphorus levels.

Due to the widespread consumption of processed foods and sugary drinks, many health experts are increasingly concerned about phosphorus overconsumption in the modern Western diet. Estimates suggest that phosphorus additives could account for 10% to 50% of total phosphorus intake in these diets.

For reference, one can of cola typically contains about 50 to 60 milligrams of phosphoric acid. Some flavored bottled waters may contain up to 85 milligrams of phosphorus per serving.

According to health guidelines, a daily phosphorus intake up to 4,000 milligrams is considered the upper safe limit for most healthy adults. Consuming more than this amount could potentially lead to negative health outcomes.

People with acute kidney conditions are advised to limit phosphorus intake to no more than 800 milligrams per day, since their kidneys may not be able to eliminate the excess effectively.

Better Beverage Options

If you’re trying to cut back on phosphoric acid but still enjoy fizzy drinks, there are alternative beverages available.

Clear sodas like lemon-lime flavors, ginger ale, and flavored sparkling waters often contain little or no phosphoric acid.

To check phosphorus content in packaged foods and drinks, read the ingredient list carefully. Look for terms like “phosphoric acid” or other phosphorus-containing additives such as “sodium phosphate.”