The Importance of Phosphorus for Bone Health

The Importance of Phosphorus for Bone Health

Phosphorus, often overshadowed by its counterpart calcium, plays a crucial role in maintaining strong and healthy bones. In this article we will delve into the significance of phosphorus, its sources, absorption, and its impact on bone health in cats and dogs. Whether you are a pet owner seeking to optimize your furry friend’s diet or a veterinary professional looking to deepen your knowledge, this article will provide you with valuable insights.

What is Phosphorus?

Phosphorus is a vital mineral that ranks second only to calcium in terms of abundance within the body. Together, calcium and phosphorus work in harmony to build and maintain healthy bones and teeth. In fact, bone is made of calcium-phosphate. While calcium is often in the spotlight, it is important not to overlook the essential role that phosphorus plays in overall bone health.

Forms of Phosphorus

Phosphorus exists in two forms: organic and inorganic. Organic phosphorus is naturally present in the body and in various food sources, while inorganic phosphorus is obtained through dietary supplements. The absorption rates for these two forms differ, with organic phosphorus being absorbed by the gut microbiome at approximately 40-60%, while inorganic phosphorus boasts a higher absorption rate of around 90%.

The Role of Phosphorus in the Body

Beyond its contribution to bone health, phosphorus serves several other crucial functions within the body. It aids in waste filtration by the kidneys, plays a vital role in energy storage and utilization, and even helps reduce muscle pain post-workout. Moreover, phosphorus is integral to the growth, maintenance, and repair of tissues and cells, as well as the production of DNA and RNA. It also assists in the balance and utilization of other essential vitamins and minerals, including vitamin D, iodine, magnesium, and zinc.

Balancing Calcium and Phosphorus

Maintaining a delicate balance between calcium and phosphorus is essential for optimal bone density and the prevention of conditions such as osteoporosis. While both minerals are crucial, it is important to note that excessive phosphorus intake can pose risks. Studies have shown that elevated phosphorus levels, often resulting from kidney disease or excessive dietary phosphorus consumption in relation to calcium, have been associated with an increased risk of cardiovascular disease. Therefore, it is vital to strike a balance between these two minerals to ensure the overall well-being of your pet.

Issues of Excessive Phosphorus

Having too much phosphorus in the body is a more common concern than having too little. In pets, this can be particularly problematic as they may not consume sufficient water, especially when fed a primarily dry kibble diet. The accumulation of inorganic dietary phosphorus can lead to irritation of the liver, kidneys, or urethra. While it is impossible to eliminate phosphorus entirely from a diet, increasing the moisture content of your pet’s food with a whole, fresh, raw or gently cooked food can help mitigate issues caused by excessive phosphorus exposure.

Sources of Phosphorus in Pet Diets

Phosphorus can be found in various food sources for both cats and dogs. Organic dietary phosphorus is present in dairy products, salmon, beef, poultry, pork, legumes, grains, and many processed food items. While it is challenging to achieve a zero-phosphorus diet, increasing the moisture content of your pet’s food can help offset the potential adverse effects of phosphorus overexposure.

Guidelines for Phosphorus Intake in Cats and Dogs

Regulatory guidelines and expert recommendations play a crucial role in determining appropriate phosphorus intake for pets. For cats, the American Association of Feed Control Officials (AAFCO) advises a phosphorus intake of 1.25 grams per 1000 calories for maintenance and 2 grams for growth. However, it is important to note that CKD-optimized diets should have significantly lower levels of phosphorus. In the case of dogs, the daily recommended phosphorus intake per kilogram of body weight is 22.25mg. Puppy food often contains higher levels of phosphorus and calcium to support bone growth, while larger breed dogs require less phosphorus for steady growth. Elderly dogs and those with chronic renal failure should be fed a diet containing less than 1% phosphorus and higher levels of dietary calcium.

Transitioning to a Balanced Diet

If you are considering transitioning your pet from a kibble-based diet to a moisture and nutrient-rich natural food, it is important to do so gradually and with proper research and planning. Fetching Foods offers a range of products, both raw and gently cooked, designed to meet the appropriate nutrient recommendations for cats and dogs. Custom Meals can also be formulated to address specific needs, such as reduced phosphorus levels for pets with chronic kidney disease or increased dietary calcium for optimal bone health. One option to increase moisture and palatability is to add bone broth as a topper to your pet’s existing food or incorporate it into their water to promote hydration.

Oral Health and Phosphorus

While bone health is paramount, oral health should not be overlooked when considering your pet’s overall well-being. While most pet owners do not brush their animals’ teeth, there are alternative methods to maintain oral hygiene. Commercially available products and chewable bones are commonly used, but it is crucial to choose safe options tailored to your specific pet. For dogs, Fetching Foods offers Duck Necks as a natural and safe alternative for oral health and sensory stimulation, without the dangers of tooth damage. Custom Meals can also be made with larger meat chunks, allowing pets to clean their teeth while eating. Additionally, dehydrated single ingredient jerky products, which we offer, are enjoyed by both cats and dogs, providing a tasty and beneficial treat for their dental health.


Phosphorus plays a vital role in maintaining healthy bone structure and function in cats and dogs. By understanding the importance of phosphorus, its sources, absorption rates, and the delicate balance required with calcium, pet owners and veterinary professionals can make informed decisions about their pet’s diet. While excessive phosphorus intake can pose risks, careful planning and the adoption of appropriate nutrient recommendations can help ensure the optimal health and well-being of our furry companions. So, let’s provide them with the best possible care by incorporating balanced diets and oral health practices into their daily routines.

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