Can Collagen Cause Kidney Stones?

You’ve been reading all about the health benefits of collagen. But, if you’ve ever had kidney stones, you know it is a good idea to make sure any supplement you take isn’t linked to kidney stones. Lately, I’ve been getting a lot of questions about if it is ok to take collagen with kidney stones.

Let’s set the record straight on collagen and kidney stones!

What is Collagen?

Collagen is a protein found in many body tissues. It is actually the most abundant protein in your body. It makes up most of your connective tissue, skin, tendons, bones and cartilage.

There are more than 20 types of collagen. But, type I collagen is the most common type of collagen in your body. This type of collagen gives your skin, bones, tendons and ligaments structure.

Where Can I Get Collagen?

Your body can get collagen from two sources: your diet and what your body makes.

Dietary Collagen

Collagen is only found in foods made from animal flesh. Here are some common foods with collagen:

• Beef, pork, poultry, game meats
• Fish & shellfish
• Bone broth

Collagen supplements have also become very popular the past few years.

It is important to remember that in order to digest any protein, including collagen from food or a supplement, it must be broken down into individual amino acids. So, taking collagen itself doesn’t guarantee that collagen will end up where you want it to be.

It might make more sense to be sure to eat enough of the nutrients your body needs to make collagen. Your body needs lots of nutrients to make collagen. Vitamin C, zinc and copper are especially important.

What Are Collagen Supplements?

There are many different kinds of collagen supplements available. Collagen products range from protein powders, pills and liquid form.

You can also find collagen peptide supplements. Collagen peptides are collagen that is broken down into the individual amino acids. Proline, glycine and hydroxyproline are the main amino acids in collagen.

Potential Health Benefits of Taking Collagen

The internet is full of articles touting the “benefits” of collagen. Some of the more common reported benefits of collagen are:

• Help wrinkles and smooth skin
• Boost skin elasticity
• Make finger and toenails stronger
• Ease joint pain
• Improve gut and heart health
• Keep bones healthy

There is a notable lack of research to support most collagen health claims.

Helping knee pain is one of the few benefits of collagen that is backed by quality (albeit limited) research. One study found reduced knee pain in athletes with knee pain after taking collagen for 12 weeks. (1) Another study found that acetaminophen PLUS collagen supplements helped improve knee pain compared to acetaminophen alone. (2)

It is commonly reported that collagen (and especially collagen peptides) are an “easy to digest” protein. Unless you have chronic diarrhea or other significant medical condition, there is no reason to think your body can’t digest protein normally. Even if you do, there isn’t research to show that protein in collagen supplements is easier to digest compared to protein found in food.

Link Between Protein & Kidney Stones

At the end of the day, collagen supplements are essentially a specialized protein supplement. We know that too much protein, especially from non-dairy animal sources, can cause kidney stones. (3) (4) (5) (6)

Eating too much protein can cause:

• Higher urine acid levels (6)
• Higher urine calcium levels (5)
• Higher urine oxalate levels (due to the liver making oxalate from amino acids) (7)
• Lower urine citrate levels (8)

All of these changes in urine chemistry can increase the risk of kidney stones.

Can Collagen Cause Kidney Stones?

There is no research specifically investigating collagen and kidney stones. However, as a registered dietitian and kidney stone specialist, I do think collagen can cause kidney stones. Especially if the collagen supplement is adding unnecessary, extra protein to your day.

Why exactly do I think collagen can cause kidney stones?

Collagen is Animal Protein

We know that eating too much protein, especially from animal sources, increases the risk of kidney stones. (3) (4) (5) (6) By definition, collagen is animal protein – collagen is only found in animal foods.

So, a collagen supplement is adding (likely unnecessary) animal protein to your daily intake.

One of the reasons too much animal protein can cause kidney stones is that your liver can make oxalate from amino acids. Specifically, the amino acids hydroxyproline and glycine are made into oxalate in your liver. (7) Collagen is made mostly of these two amino acids, along with proline. So, it is very possible collagen supplements could cause your liver to make much more oxalate, which would increase risk of kidney stones.

What About Vegan Collagen?

Collagen is protein found only in animals. Plants do not make collagen, so a natural vegan collagen supplement is not possible.

However, there are many “vegan collagen” products on the market. From my research, most of these products are simply a man-made mixture of compounds found in collagen. These products are often made from genetically engineered bacteria or yeast. (9)

Most People Are Eating Too Much Protein

This may come as a surprise. Despite the hype around protein, most people in the United States are eating about 30% more protein than they need. (10) For most of us, collagen supplements are just adding extra protein our body doesn’t need. In this case, collagen could definitely cause kidney stones.

Everyone has different protein needs. The amount of protein right for you depends on your body size, lifestyle, eating patterns and medical history. A registered dietitian is the best person to help you learn how much protein is right for you.

Can I Take Collagen with Kidney Stones?

Is it safe to take collagen with kidney stones? Answer: it depends.

Kidney stone prevention is NOT the same for everyone. If you have had kidney stones in the past, it is imperative you get a 24-hour urine test to understand why your kidney stone formed. Those results tell us exactly what YOU can do to prevent kidney stones.

If you make kidney stones because of high urine calcium, high urine oxalate or low urine pH, you should avoid collagen and other protein supplements. It is always best to get nutrition (including protein!) from food before supplements.

However, some people with kidney stones may be having a hard time eating enough protein. This is especially true if you are sick, older or have higher protein needs. If you can’t get enough protein from food, collagen or other protein supplement can help you get enough protein.

Happy Eating!

Melanie