What Is Tricalcium Phosphate?

What Is Tricalcium Phosphate?

Tricalcium phosphate is a supplement form of calcium phosphate used to treat or prevent calcium deficiency. It is also used as an anti-caking agent in powdered food items and as an additive in some processed foods to boost calcium content.

Several forms of calcium supplements are available. Calcium carbonate and calcium acetate are the most common, but tricalcium phosphate is another option. Tricalcium phosphate does not offer any advantage over other calcium forms.

Tricalcium phosphate is considered safe to use as a food additive and supplement. Still, there are some people for whom it has contraindications, and there can be interactions and side effects. This article reviews tricalcium phosphate as a calcium supplement, its potential uses, and its side effects.

Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLabs, or NSF. 
However, even if supplements are third-party tested, that doesn’t mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.

Supplement Facts

  • Active ingredient(s): Calcium
  • Alternate Name(s): Tribasic calcium phosphate, bone phosphate of lime, calcium phosphate
  • Suggested Dose: Refer to the Recommended Dietary Allowance (RDA); do not exceed more than 500 milligrams (mg) at one dose
  • Safety Considerations: No need to take more than the RDA; avoid exceeding the tolerable upper limit (TLU). Avoid this form of calcium if you have kidney disease.

Uses of Tricalcium Phosphate

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Tricalcium phosphate is one of many forms of calcium supplements available. Some people take calcium supplements if they are not getting enough calcium from their diet alone. Calcium supplements have also been shown to help maintain bone density and prevent osteoporosis.

Tricalcium phosphate is also used as an anti-caking agent in powdered food items and as an additive in some processed foods to boost calcium content.

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Calcium Deficiency

Calcium deficiency can be asymptomatic but over years can result in reduced bone strength, leading to osteomalacia or osteoporosis.

Other signs of calcium deficiency may include:

  • Muscle cramps and spasms
  • Tingling in the hands and feet
  • Memory difficulty
  • Brittle nails and bones

More severe signs of calcium deficiency include:

  • Renal or brain calcification
  • Depression
  • Cataracts
  • Heart failure
  • Seizures
  • Coma

What Causes a Calcium Deficiency?

Calcium deficiency can occur due to too little calcium in the diet or increased calcium loss.

People who do not get adequate calcium in their diet are at increased risk of becoming deficient. Postmenopausal women are also at a higher risk of developing a calcium deficiency. This is because menopause decreases estrogen production, which lowers the amount of calcium the body absorbs and increases how much calcium is lost.

Hypocalcemia (low blood levels of calcium) can be related to:

  • Vitamin D or magnesium deficiency
  • Hypoparathyroidism
  • Impaired resorption of calcium
  • Critical illness
  • Use of medications, such as bisphosphonates, Cisplatin, and proton pump inhibitors

How Do I Know If I Have a Calcium Deficiency?

Calcium levels can be measured in the blood. In healthy people, normal calcium levels range from 8.8 - 10.4 milligrams/deciliter (mg/dl). Calcium is bound to albumin, so if blood albumin levels are depleted, calcium levels may falsely appear depleted.

In some cases, ionized calcium levels are preferred.

Dual x-ray absorptiometry (DEXA) is a test that assesses bone mineral density but it can also provide information on an individual's calcium status over their lifetime.

What Are the Side Effects of Tricalcium Phosphate? 

Supplementing with tricalcium phosphate is generally considered safe, but there are some risks and precautions. Sometimes tricalcium phosphate may cause certain side effects, such as:

Precautions

People who are pregnant or breastfeeding, and those with certain health conditions, like kidney stones or parathyroid gland disorder should talk to their healthcare providers before taking tricalcium phosphate.

People with kidney disease should not use tricalcium phosphate to supplement calcium. They may have problems clearing the additional phosphorus resulting in high blood levels of phosphorus (hyperphosphatemia).

Tricalcium phosphate can make it more difficult for your body to absorb other medications. If you currently take any prescription or over-the-counter (OTC) drugs, discuss with your healthcare provider how they may interact with tricalcium phosphate. 

Dosage: How Much Tricalcium Phosphate Should I Take?  

Calcium is abundant in many common foods, like dairy products and green, leafy vegetables. Most people will get sufficient calcium by eating a well-balanced diet.

The Recommended Dietary Allowance (RDA), or the average daily level of intake needed to meet your nutrient needs for calcium, is stated in milligrams (mg) per day. It varies by age and whether someone is post-menopausal:

  • Infants (0 to 6 months) need 200 milligrams/day
  • Infants (7 to 12 months) need 260 milligrams/day
  • Toddlers (1 to 3 years) need 700 milligrams/day
  • Children (4 to 8 years) need 1,000 milligrams/day
  • Children and teens (9 to 18 years) need 1,300 milligrams/day
  • Adults (19 to 50 years) need 1,000 milligrams/day
  • Adults (51 to 70 years) need 1,200 milligrams/day
  • Adults over 70 years need 1,200 milligrams/day

Your body will adjust how much calcium it absorbs based on the quantity consumed. For example, if you take in 200 milligrams of calcium, your body will absorb about 45%. However, if you take in 2,000 milligrams of calcium, absorption may drop to 15% since the amount is more than one needs.

Your body cannot absorb more than 500 milligrams of calcium at one time. Therefore, you should not take more than this amount at once. You can split up your dosage amounts throughout the day.

If you are considering supplementing with tricalcium phosphate, remember that you will still receive calcium in the food you already eat. You may want to talk to your healthcare provider or pharmacist to determine which dosage is right for you.

What Happens If I Take Too Much Tricalcium Phosphate?

If you take too much calcium in the form of supplements, you may feel side effects such as gas, bloating, or constipation.

Supplementing too much tricalcium phosphate can lead to hypercalcemia or increase the risk of developing kidney stones or possibly a cardiovascular event, like a heart attack.

Interactions

Calcium supplements have the potential to interact with some medications, making it difficult for your body to absorb the calcium or the drug being taken. You should take your supplements separately from these medications.

If you currently take any prescription or over-the-counter (OTC) drugs, discuss with your healthcare provider how they may interact with tricalcium phosphate. 

Some medications that may interact with tricalcium phosphate include, but are not limited to:

  • Certain diuretics, such as loop diuretics (e.g., furosemide) and thiazide diuretics (e.g., hydrochlorothiazide)
  • Antacids: Some popular OTC antacids are calcium carbonate and should be counted towards your total calcium intake. For example, TUMS and Rolaids provide calcium. 
  • Quinolone antibiotics, such as Cipro (ciprofloxacin): Taking the antibiotic two hours before or after your calcium supplement is recommended.
  • Synthroid (levothyroxine)
  • Tivicay (dolutegravir)
  • Lithobid (lithium)

How To Store Tricalcium Phosphate

All supplements should be stored out of reach of children and pets to prevent accidental consumption. Tricalcium phosphate should also be stored at room temperature (between 68 F and 77 F) and away from heat and moisture.

Similar Supplements

Calcium carbonate and calcium acetate are other forms of calcium supplements. Other forms include calcium sulfate, ascorbate, microcrystalline hydroxyapatite, gluconate, and lactate.

These forms differ in the amount of elemental calcium they have. Generally, tricalcium phosphate does not offer any advantages over the other calcium forms.

Tricalcium phosphate is sometimes referred to as tribasic calcium phosphate, bone phosphate of lime, or calcium phosphate.

Frequently Asked Questions

  • Is tricalcium phosphate bad for you?

    Tricalcium phosphate is a common additive in foods and it is also used as a nutritional supplement. It is considered safe for human consumption. 

    People who are considering using tricalcium phosphate should discuss it with their healthcare provider. Certain medical conditions are contraindicated. If you have kidney stones or kidney disease or have parathyroid gland disorder, you may not be able to take tricalcium phosphate. 

    Some medications and supplements should not be taken with tricalcium phosphate. For example, antacids, diuretics, and certain antibiotics can interact with calcium supplements.

  • How does tricalcium phosphate compare to other calcium supplements?

    Elemental calcium is the amount of calcium released during digestion that becomes available for absorption. Calcium phosphate and calcium carbonate have the highest concentration of elemental calcium at 40%. Calcium citrate comes next at 21%, calcium lactate at 13%, and calcium gluconate at 9%.

    Determining which form of calcium supplement is suitable for you is best determined with your healthcare provider. Discuss your diet, existing health conditions, and medications as you evaluate tricalcium phosphate. The best way to get adequate calcium is by consuming calcium-containing foods. 

Sources of Tricalcium Phosphate & What to Look For

Calcium is abundant in dairy products. Tricalcium phosphate is also found in foods fortified with calcium and household products like baby powder and toothpaste. Antacids also contain calcium. Tricalcium phosphate is also available in supplement form.

If you need calcium supplementation, be sure to discuss with your healthcare provider the proper type of supplement for you and the appropriate dosage.

Food Sources

Foods high in calcium include:

  • Dairy products, like milk, cheese, cottage cheese, cream cheese, and yogurt
  • Calcium-fortified orange juice
  • Soy products, such as soy milk and tofu
  • Fish, like salmon and sardines
  • Green vegetables, like broccoli, kale, spinach, and turnip greens

Additionally, tricalcium phosphate is a food additive that is used to prevent powdered foods (like powdered milk or non-dairy creamers) from clumping. It can also be found in baby powder, toothpaste, and antacids. As an additive, it is odorless and tasteless.

Tricalcium Phosphate Supplements

Calcium phosphate is generally recognized as safe when produced with good manufacturing practices.

Tricalcium phosphate supplements are best taken with food and a full glass of water.

Some calcium supplements are combined with other vitamins and minerals. Commonly, they are combined with vitamin D or magnesium. Be sure to read the labels carefully to see whether the supplement you are considering contains other nutrients.

Tricalcium phosphate is vegan unless derived from dolomite, oyster shell, or bone meal. In addition to not being vegan, supplements made from those ingredients may contain high levels of lead and other metals. Looking for supplements that have been third-party tested can help to avoid supplements that may be contaminated with other metals.

Read the label carefully, especially if you have allergies or sensitivities, to determine the source of the ingredients and whether the supplement you are considering is free of allergens. Additionally, the supplement facts label should list the quantity of elemental calcium.

Be wary of supplements that make unsubstantiated claims. No supplement should claim that it can treat, cure, or prevent diseases.

Summary

Tricalcium phosphate is just one of many forms of calcium supplements available. It is commonly used as a food additive, but can also be taken as a nutritional supplement. For some people who cannot get enough calcium from foods, supplementation is needed. However, it is generally best to get your calcium through your diet.

If you need calcium supplements, discuss with your healthcare provider which form and what dosage is most appropriate for you.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  4. Rosen HN. Patient education: calcium and vitamin D for bone health (beyond the basics). UpToDate.

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By Jennifer Lefton, MS, RD/N, CNSC, FAND
Jennifer Lefton, MS, RD/N-AP, CNSC, FAND is a Registered Dietitian/Nutritionist and writer with over 20 years of experience in clinical nutrition. Her experience ranges from counseling cardiac rehabilitation clients to managing the nutrition needs of complex surgical patients.