Blog
April 13, 2023

Kidney Nutrition: Fluids and PKD


Starting this month, look for PKD curated nutrition content including blogs and recipes in the monthly newsletter by renal dietitian Emily Campbell.

A bit about Emily. She is a registered dietitian and certified diabetes educator with a master’s degree in foods and nutrition from Western University. Emily specializes in renal nutrition helping those with kidney disease overcome the confusing world of nutrition to promote health and make nutrition changes. Emily lives in Toronto, Ontario and can be found at kidneynutrition.ca.

Got questions for the dietitian? Stay tuned for opportunities to ask the dietitian question in an upcoming newsletter.

Whether you’ve just been diagnosed with Polycystic Kidney Disease (PKD) or have been living with it for a while, you’ve probably heard you need to be drinking more fluids. This is one of the first and probably most challenging nutrition recommendations to follow with PKD. While this is good nutrition advice for those with PKD, let’s break it down a few things to help you.

In this blog, we will cover:

  • The role of fluids with PKD.
  • How much fluids you should drink.
  • What types of fluids you should choose.
  • Tips and tricks for getting adequate fluids with PKD.

Fluids and PKD

The kidneys play an important role in maintaining fluid balance in the body.  But with PKD the amount of fluid we consume has many other benefits, like:

  • Reducing vasopressin, a hormone linked to cyst growth in PKD. Vasopressin increases cyst growth by directing fluids to the cysts which can cause PKD to progress quicker. Vasopressin can also be affected by other nutrition strategies such as sodium and protein - stay tuned for future blogs on these topics. But for now, adequate fluids reduce the stimulation of vasopressin and therefore reduce cysts formation, which is why it is important to drink adequate fluids with PKD.
  • Lowering the risk of developing kidney stones, a common comorbidity of PKD.
  • Preventing dehydration which can lead to acute kidney injury and temporary reduced function.

How Much Fluids Should You Drink?

Fluids are pretty much any liquid at room temperature. This includes water, coffee, tea, and soup, just to name a few. Consistently having adequate fluid intake will reduce vasopressin levels which helps to prevent cyst formation with PKD. But drinking enough can be a challenge in real life.

Of course, water should be majority of our fluid choices but some of these others count too. While current recommendations for PKD are 2-3 Litres of water per day to start, a personalized approach should be taken; and speaking with your nephrologist or renal dietitian can help. Depending on your medications (for example if you are on Tolvaptan you may need more fluids), activity level, the environment you live in, health status, and kidney function you may need more or less fluids than this per day. It is also important to follow-up with your healthcare team for regular monitoring of your electrolytes in your blood, as high amounts of fluids can lead to low levels of sodium in the blood, called hyponatremia. So, with fluids and anything in life, too little and too much is not good.

How much is 3 Liters of fluid per day?   This is about 12 cups or 96 ounces per day. So, you may be thinking this is a significant amount of fluid. But it is not that different than what many Canadians should be consuming per day. You may have heard that we need 6-8 glasses (or cups) of fluids per day, this is only about 1.5 -2 Litres per day.  In reality Canadian adults should be drinking 2.7 Litres per day for women and 3.7 Litres per day for men. So not much of a difference compared to PKD recommendations. 

What Types of Fluids Should You Choose?

Most of your fluid intake should be from good ol’ water. Aiming for that 2 to 3 Litres per day to start. Any additional fluids are a bonus.

You may be asking what about coffee and tea with PKD. The short answer is, yes these can be consumed, but in moderation. Aim to limit coffee and tea to 2 cups per day. If you have kidney stones, you may want to consider limiting tea, and especially black tea like Orange Pekoe or Earl Grey, to only 1 cup per day as these can be a source of oxalates.

But remember, what you put in your coffee and tea is also important. So aim to limit added sugars including honey and maple syrup and if you use creamers choose ones with no phosphorus additives in the ingredient list.

Limiting fluids like sugar sweetened beverages such as juice or pop is important for overall health. When it comes to drinking alcohol, moderation is the key because it can impair our judgment, increase our blood pressure, and lead to progression of kidney disease. It is important to speak with your doctor before drinking alcohol as it may interact with some medications. You may also be interested in learning about Canada’s new low risk alcohol guidelines here.

How To get Adequate Fluids with PKD

Drinking plain water everyday can get boring!  But that doesn’t need to be the case. In fact, lemon can help to decrease risk of kidney stones forming because it provides a source of citrate, but it may also add some flavour to your water with PKD. Some other ways of infusing your water with flavour without added sweeteners are using fruit and herbs like strawberries with mint or cucumber, or citrus like lemon and lime are great flavour combinations. You may be wondering if you can use carbonated waters. And the answer is yes. These can be a great option from time to time. Just look for ones that are unsweetened.

Tips and Tricks for Getting Adequate Fluids with PKD

Here are some of tips and tricks to keep you on track:

  • Get a water bottle. Taking your fluids with you to go can help keep you on track. But his is also a great way of measuring how much you’ve had each day.
  • Get into a routine. Drink when you first wake up, space it out throughout the day and aim to have some at meals, and after you use the bathroom (and have washed your hands).
  • Track it. Tracking your fluid intake using apps like Cronometer or MyFitnessPal. Or use technology to remind you like setting a calendar alert in your phone or using a “smart” water bottle can help.

The Goal with Fluids

Staying hydrated is important and helps to decrease cyst formation with PKD. But it can be a challenge to drink enough. Use these tips and tricks to choose fluids that nourish your body and help to manage your PKD. But it is always best to speak with your healthcare team to determine how much fluid is right for you.

Written by: Emily Campbell, RD CDE MScFN is a Registered Dietitian and Certified Diabetes Educator with a Master’s Degree in Foods and Nutrition. Emily specializes in renal nutrition helping those with kidney disease overcome the confusing world of nutrition to promote health. Emily can be found at kidneynutrition.ca.