What’s the maximum safe dose of phosphorus?

Adverse effects of exceeding the maximum safe dose of phosphorus

Although phosphorus is necessary for health, too much can lead to adverse effects. The maximum safe dose is 4,000 mg for adults and teens. Limiting dairy, meat, and processed foods could protect you from phosphorus toxicity.

Health benefits of phosphorus

Phosphorus, an essential mineral. We have to get it from food.

Phosphorus is the second most abundant mineral in the human body. It represents about 1% of the total body weight![1]

Phosphorus is critical for health. It’s involved in DNA and protein synthesis, energy production, and activation of enzymes. Also, phosphorus is involved in the renal and cardiovascular system as well as on brain health.[2,3]

Most noteworthy, phosphorus is necessary for strong bones and teeth. Actually, 85% of total phosphorus in the body is stored in bones and teeth. In fact, phosphorus is a key structural component of tooth enamel.

Phosphorus, calcium, and magnesium, which are crucial for preventing osteoporosis, are regulated by hormones, such as vitamin D and parathyroid hormone (PTH).

What’s the recommended daily intake?

The recommended daily intake of phosphorus is 700 mg for adults. Both for men and women.

Children older than 9 years and teenagers need higher doses of 1,250 mg a day, though. They have high phosphorus requirements, due to rapid bone growth.

What’s the maximum dose of phosphorus I can safely take a day?

The maximum safe dose of phosphorus is 4,000 mg for adults, teenagers, and children older than 9 years.

Additionally, the maximum dose for elderly people and younger children is 3,000 mg.

Also, pregnant women shouldn’t get more than 3,500 mg of phosphorus a day.

Only people who are receiving supplemental phosphorus under medical supervision could exceed these maximum safe limits.

Side effects of exceeding the daily upper dose of phosphorus

As a rule of thumb, high phosphorus intakes rarely produce adverse effects in healthy people.

But, extremely high phosphorus intakes, even over short periods, could interfere with calcium metabolism, negatively affecting the kidneys, causing bone loss, vascular calcification, and endothelial dysfunction. Hence, excess phosphorus may contribute to renal failure, cardiovascular disease, cancer, and osteoporosis![4]

Furthermore, phosphorus can interact with certain medications.

So, you should always consult your physician before taking any dietary supplement.

Do I need dietary supplements?

Healthy people don’t need dietary supplements. Actually, most Americans consume more phosphorus than the recommended amounts.

Phosphorus deficiency is rare in the United States. In most cases, a disease, not a poor diet, leads to low levels of phosphorus. 

Low phosphorus levels are bad for our health. Anorexia, anemia, muscle weakness, bone pain, increased infection risk, and confusion are only a few side effects of phosphorus deficiency.

Can I get too much phosphorus from food?

There is a wide variety of foods high in phosphorus. Milk and dairy are the best dietary sources of phosphorus. Meat, poultry, and fish are also particularly high in phosphorus.

Vegans, vegetarians, and people who follow a plant-based diet can get adequate amounts of phosphorus as well. Seeds, nuts, vegetables, and whole-grains are great dietary sources. See a list of plant-based foods high in phosphorus here.

However, phosphorus in seeds isn’t well-absorbed. It’s in the form of phytic acid. This is the storage form of phosphorus. Thus, you should consume a wide variety of foods to get the recommended daily intake.

In contrast, high phosphorus intakes might be a sign of a poor, unhealthy diet. Actually, there are two types of phosphorus in food; natural and added.

Natural (or organic) phosphorus is naturally present in foods. It’s slowly absorbed. Also, we absorb only 40-60% of natural phosphorus in foods.

On the other hand, high amounts of added (or inorganic) phosphorus are found in processed foods as phosphate additives. Phosphate-based additives are used to improve the consistency and appearance of products. Furthermore, inorganic phosphorus salts found in food additives are rapidly and efficiently (80–100%) absorbed.

Thus, people who follow a standard Western diet, which is rich in processed and animal-based foods, consume about double the required amount of phosphorus!

This doesn’t mean that processed food is good for you. Actually, excess phosphorus is bad for our health. It may contribute to cardiovascular disease, renal failure, osteoporosis, and even cancer. Further research is required, though.[1]

In any case, people shouldn’t consume much higher doses of phosphorus than the recommended daily intake. Limiting dairy, meat, and processed foods is enough in most cases.