What Do Those Nutrients Do? Phosphorus

Phosphorus seems to have a bad reputation. “Watch out for too much phosphorus! Make sure there isn't too much phosphorus in your dog's diet!”

That is true; you don't want too much phosphorus in your dog's diet.

Conversely, though, you don't want too much of anything in your dog's diet. Too much of any good thing just isn't good. What you do want is the right amounts of nutrients, in the right proportion.

So why is it, for example, that you're not very likely to be told to watch out for too much calcium in your dog's diet? 

What is it that makes phosphorus the bad guy? The reason for that is actually quite simple. Phosphorus is abundant in many foods, while calcium if we stick with that example, not so much. There is plenty of phosphorus in meats, organ meats, fish, eggs, dairy products, whole grains … you name it.

For example, 100 grams of cooked ground beef contains 250 mg of phosphorus and only 16 mg of calcium. 100 grams of cooked chicken breast has 228 mg of phosphorus and 15 mg of calcium. Cooked chicken liver contains 405 mg of phosphorus and only 11 mg of calcium!

Do you see the problem here?

The calcium to phosphorus ratio in an adult dog diet should be about two parts of calcium for every part of phosphorus! And not only that there is a high content of phosphorus in animal proteins, high phosphorus levels interfere with calcium uptake.

So does that make phosphorus a bad guy?

Phosphorus is a vital macro mineral; your dog has to have it to survive. But its abundance in foods and easy absorption through the digestive tract make it a challenge to keep it under control. That, however, doesn't make its function any less important.

About 86% of the body's phosphorus is contained in the bones and teeth. A deficiency in either calcium or phosphorus can lead to bone deformities or weakness. But just as with calcium, bones are not the only place where phosphorus is found.

Phosphorus is also present in the bloodstream, cell, and tissues throughout the body. The kidneys are in charge of maintaining proper phosphorus levels.

What does phosphorus do, besides keeping bones strong?

Phosphorus is needed for cell membranes. Cell membranes are vital for cell integrity; without a membrane holding it together, there would be no cell. What should stay out is kept out, what should stay in is kept in, and what should make it through it allowed to get through.

Phosphorus is also a component of DNA. The backbone of the DNA is constructed from a repeated pattern of sugar and phosphate groups.

Phosphorus is involved in energy storage and transfer. The energy your dogs derives from food, for example, is stored in the form of ATP (adenosine triphosphate). ATP contains a large amount of chemical energy, which is used for metabolic processes, cell division, muscle contraction, and more.

Phosphorus supports nerve function.

Phosphorus is a coenzyme for several vitamins (niacin, riboflavin, thiamin and pyridoxine)

Ironically enough, phosphorus is needed for calcium metabolism.

Phosphorus is not a bad guy.

It is a very important nutrient. The problem is, that it is very easy for an animal protein based diet to contain too much of it, particularly in proportion to calcium.

That doesn't make phosphorus any less important for your dog's body.

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  1. I am wandering around here on my first day as a Blog-Train member and came across your blog. I found your calcium to phosphorus ratio article very interesting. I am surprised to find such an article here.

    Vitamin E is a partner here also. There can be no Vitamin E level in you canine if the Calcium vs Phosphorus ratio in not correct. This will lead to severe problems if all three are not kept with in a strict ratio. Canine absorption of E via the Sun is not done with any regularity or sufficiency to insure the task of providing it to dogs. They do not deal with the external absorption of Vitamin E as humans do.

    When I decide to build a new recipe for my GSD's I start with these three essentials and work outward with other nutritional necessities adding in more obscure minerals as I go. There are many fresh or dried greens and water plants like kelp that can help you come up with a good tasting nutritionally sound mix. (I use only natural and holistic ingredients)

    Thank you for your time and effort to present this article.

    My Regards,
    Bill H.

    1. Hi Bill, thank you for visiting! Curious, why this article surprised you here?

      Great comment - didn't you mean vitamin D, though? I will be writing about the other essential nutrients in following articles.


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