Do Clams Contain Phosphorus? A Detailed Nutritional Breakdown

November 3, 2025 •

3 min read

According to the National Kidney Foundation, a 3-ounce serving of cooked clams provides a substantial 287 mg of phosphorus. Yes, clams contain phosphorus, a mineral that is a crucial component for building strong bones and teeth, and essential for numerous cellular functions throughout the body.

Quick Summary

Clams are a significant natural source of phosphorus, essential for bone health, energy production, and cellular repair. This shellfish also offers other key nutrients like Vitamin B12, iron, and omega-3s, contributing to overall health.

Key Points

Significant Source: Clams are a rich natural source of the essential mineral phosphorus, with a 3-ounce serving of cooked clams providing a notable amount.
Essential for Health: Phosphorus plays a crucial role in the body, primarily in building and maintaining strong bones and teeth, and is involved in energy production and cellular repair.
High Bioavailability: The organic phosphorus in clams, like other animal-based foods, is more easily absorbed by the body than phosphorus from plant sources.
Nutrient-Dense Food: Beyond phosphorus, clams are packed with other key nutrients including Vitamin B12, selenium, iron, high-quality protein, and omega-3 fatty acids.
Considerations for Kidney Health: Individuals with chronic kidney disease may need to monitor their phosphorus intake from all sources, including clams, and should consult a dietitian or doctor for guidance.
Versatile Ingredient: Clams can be prepared in various healthy ways, such as steaming or adding to stews and chowders, making them a versatile and healthy dietary addition.

Clams: A Rich Source of Natural Phosphorus

Phosphorus is a vital mineral, and clams are an excellent dietary source. For instance, a 3-ounce (85g) serving of cooked, moist heat clams contains approximately 287 mg of phosphorus, which is a considerable portion of the Recommended Dietary Allowance (RDA) for most adults. The phosphorus found in animal sources, like shellfish, is generally more bioavailable than that from plant sources. This means the body can absorb and utilize the mineral more efficiently when it comes from clams and other seafood.

The Critical Role of Phosphorus in the Human Body

Phosphorus is the second most abundant mineral in the body and is involved in many essential bodily functions. Its primary roles include:

Bone and Teeth Formation: About 85% of the body's phosphorus is found in bones and teeth, forming a strong and rigid structure.
Energy Production: It is a key component of Adenosine Triphosphate (ATP), the body's main energy molecule.
Cellular Growth and Repair: Phosphorus is a building block for DNA and RNA, essential for cellular repair and growth.
Kidney Function: This mineral helps the kidneys filter and remove waste products from the blood.
Nerve and Muscle Function: It is necessary for nerve signaling and muscle contractions, including the regulation of a normal heartbeat.

More Than Just Phosphorus: The Complete Nutritional Profile of Clams

Beyond their significant phosphorus content, clams offer a wide array of other beneficial nutrients, making them a highly valuable addition to any diet. A single serving is a nutritional powerhouse, providing high amounts of:

Vitamin B12: Crucial for nerve function, blood cell formation, and overall brain health.
Selenium: A powerful antioxidant that protects cells from damage.
Iron: Vital for preventing anemia and supporting the healthy transportation of oxygen in the blood.
Protein: Clams are a low-fat, high-protein source, supporting muscle growth and satiety.
Omega-3 Fatty Acids: These are important for heart health and reducing inflammation.

How Clams Compare to Other Seafood for Phosphorus Content

To put the phosphorus content of clams in perspective, here is a comparison with other common seafood, based on approximate values per 3-ounce (85g) cooked serving:


Seafood Type	Phosphorus Content (mg)	Notes
Clams (moist heat)	287	Excellent source
Salmon (cooked)	~265	Also rich in omega-3s
Crab (Alaskan, moist heat)	238	Also a good source
Mussels (blue, moist heat)	242	Very good source
Oysters (eastern, raw)	118	Lower in phosphorus than clams
Scallops (breaded & fried)	73	Significantly lower in phosphorus

Special Considerations for Phosphorus Intake

While clams are a healthy food for most people, certain individuals must be mindful of their phosphorus intake. For those with chronic kidney disease, the kidneys may not be able to effectively filter out excess phosphorus, leading to potentially harmful high levels in the blood. In such cases, dietary adjustments, including moderating the intake of high-phosphorus foods like clams, may be necessary. It is crucial to consult with a healthcare provider or a registered dietitian for personalized advice, especially if you have kidney health concerns. Additional information on phosphorus can be found from authoritative sources like the Harvard T.H. Chan School of Public Health: The Nutrition Source.

Tips for Enjoying Clams Safely

Incorporating clams into your diet can be a delicious way to boost your mineral intake. For safe preparation and enjoyment, remember to:

Source responsibly: Buy shellfish from a reliable vendor to minimize the risk of food-borne illnesses.
Clean thoroughly: Scrub the shells well before cooking to remove any dirt or grit.
Cook properly: Ensure clams are cooked completely. For dialysis patients, it is especially important to avoid raw shellfish.
Watch the sodium: Some canned or processed clam products can be high in sodium. Be sure to check the nutrition labels or choose fresh options.

Conclusion

In short, the answer to "Do clams contain phosphorus?" is a definitive yes. Clams are not only a rich source of this vital mineral but also provide a host of other beneficial nutrients, including high-quality protein, Vitamin B12, and omega-3s. For most healthy individuals, adding clams to a balanced diet is a simple and delicious way to support bone health and overall bodily function. However, those with specific health conditions like chronic kidney disease should always consult a healthcare professional to ensure their phosphorus intake is managed appropriately.

Frequently Asked Questions

A standard 3-ounce (85g) serving of cooked clams contains approximately 287 mg of phosphorus. The exact amount can vary slightly depending on the species and cooking method.

Yes, clams are considered one of the seafood options with a higher phosphorus content. For example, they provide more phosphorus per serving than oysters or scallops.

Yes, the phosphorus in clams and other animal-based foods is known to be more bioavailable and easily absorbed by the body compared to the phosphorus found in many plant-based foods.

Clams are also rich in Vitamin B12, selenium, iron, and a good source of protein and omega-3 fatty acids.

Individuals with chronic kidney disease should speak with their doctor or a registered dietitian. Since shellfish contain a significant amount of phosphorus, intake may need to be limited to manage blood phosphorus levels.

For healthy individuals, consuming too much phosphorus is typically not a concern. However, in people with kidney dysfunction, high blood phosphorus can be harmful and potentially lead to soft tissue calcification.

To retain the most nutrients, including phosphorus, consider steaming or broiling clams. Always ensure they are cooked thoroughly to avoid food-borne illness.