Kidney Coach

Magnesium Citrate & Its use in Renal Disease

Alkalising the kidneys with Magnesium citrate

Creating an alkaline environment in your body is one of the key things you can do to protect your kidneys and improve your kidney function. Alkalising supplementation, alongside following an alkaline diet, is a great way to help reduce the acidic burden on your body AND your kidneys and has been shown to reduce the progression of kidney disease and even improve kidney function.

Today I wanted to talk about using magnesium citrate as an alkalising supplement. Firstly though, let’s do a quick recap on the acid-base balance in the body. 

The Acid-Base Balance

Our cells require stable conditions to ensure they work optimally. This includes optimal pH or acid-base balance. pH is the abbreviation for potential hydrogen and is a rating of acidity or alkalinity. The higher the pH reading, the more alkaline the fluid is and the lower the pH the more acidic it is. The pH range is from 0 to 14, with 7.0 being neutral. Anything above 7.0 is alkaline, anything below 7.0 is considered acidic.

Our bodies physiology operates optimally at a slightly alkaline blood pH of 7.35 to 7.45, if blood pH moves too much above or below this, enzymes stop functioning properly and illness is inevitable. 

If the blood’s pH value drops below 7.20, this denotes Acute Metabolic Acidosis, a life-threatening emergency that happens only rarely. However, what is far more common is Chronic Metabolic Acidosis (CMA)- a more subtle condition that produces small shifts in physiological pH towards acidity. Even the slight alteration in pH seen in CMA can cause metabolic and endocrine disturbances and needs to be addressed. 

Regulation of Acid-Base Balance

Our bodies are pretty amazing, they do a lot of behind the scenes work that we’re not even aware of to try and keep blood pH within normal levels. It has several ways of doing this with the main mechanisms being: 

  • The Kidneys- directly excrete acids and bases through the urine. If the body is too acidic, this process may cause the loss of valuable alkaline minerals such as calcium, magnesium, and potassium.
  • The Lungs- excrete acidic carbon dioxide through exhalation. 
  • Buffering Systems- exist in many tissues and work to regulate pH values minute to minute. Most critical of these are the blood-based buffering systems, which rely on carbon dioxide and water and alkaline minerals such as calcium, potassium, and magnesium, to maintain blood pH. When the blood is too acidic, alkaline minerals (eg. calcium, potassium, and magnesium) are leached from the bones, and magnesium is released from the muscles to offset the acidity in the blood.



 Chronic Metabolic Acidosis in CKD

I mentioned earlier that the kidneys are one of the primary organs responsible for maintaining the acid-base balance of the body; they do this by removing acid from the body through urine. 

CMA is caused by a build-up of too many acids in the blood. This happens when you consume more acids than your kidneys can excrete, don’t have enough buffering minerals or when your kidneys aren’t functionally optimally, so they are unable to remove enough acid from your blood. This means that people with CKD are at a higher risk of CMA.

The effect of acidity on the kidneys

The kidneys aren’t just responsible for maintaining the optimal pH of the body, their functioning is also highly dependent on the body’s acid-base balance. 

CMA is associated with a faster decline in kidney function and the degree of acidosis is directly associated with glomerular filtration rate (GFR). What this means is that the more acidic your body is, the worse your kidney function is likely to be and the lower your GFR.

This sets up a vicious cycle because higher acidity results in reduced kidney function which means the kidneys are less able to excrete acids from the body causing higher acidity. 

For people with CKD, the adverse effects of CMA don’t just include acceleration of kidney disease but also the development or exacerbation of the bone disease, increased muscle wasting, enhanced protein breakdown and inflammation. 

CMA contributes to kidney damage and the progression of CKD in a variety of ways. Damage is believed to occur due to:

  1. An increase in substances including aldosterone is associated with a poor GFR.
  2. Stimulation of pro-fibrotic factors which are associated with renal fibrosis (scarring).
  3. An increase in ammonia in the proximal tubule of the kidneys causes tubular toxicity and renal damage.
  4. Increased excretion of calcium and oxalate salts along with reduced citrate excretion increases the likelihood of kidney stones.

How to improve CMA?

The number one thing you can do to reduce acidity or make your body more alkaline is to change your diet. 

However, for some people, and in cases of more established CMA, just changing their diet isn’t enough to get their body into an alkaline state and they may need additional support alkalising the body. Paired with an alkaline diet, alkalising supplementation dramatically improves acid-base balance 

How do you know if you need to use an alkalising supplement?

So, you’re following an alkaline diet (hopefully!), but how do you know if you’re following it correctly, or if it is having the effect on your body that you are looking for? 

One of the easiest ways to do this is to measure the pH of your urine.

This is a super easy test that you can do at home that allows you to track your progress.

measuring urine pH

How to measure your urinary pH:

Simply purchase a pack of pH test strips from the pharmacy or online and each morning urinate on one test strip to gauge your pH. What we’re looking for is a pH of 6.75-7.25. If your pH is consistently below this, you may need to reassess the balance of alkaline-forming and acid-forming foods in your diet and/or start using an alkalising supplement. 

What alkalising supplement should you choose?


Mineral citrates are preferable for alkalisation. They have been proven to help support a healthy pH balance, without disturbing normal digestive processes. Minerals themselves, such as magnesium, calcium and potassium have an alkalising effect on the body, and when bound to a citrate ie. magnesium citrate, there is an even more pronounced alkalising effect. This is because citrate binds acidic hydrogen ions in the blood which is then converted into carbon dioxide and water. The carbon dioxide is excreted through the breath, leaving only water. 

Scientific studies have found that taking a supplement that contains alkalising mineral citrates significantly increases blood and urinary pH, meaning it makes them more alkaline.

For example, in one study 25 healthy subjects had their urine and blood pH levels measured before, during and after morning supplementation with alkalising minerals. The alkaline mineral drink containing citrates was given at 8.00 am each morning for 1 week. Results indicated that supplementation with alkaline minerals was associated with a significant and rapid increase in blood pH (remember an increase in pH means an increase in alkalinity). After 1 week of supplementation pH levels were even more alkaline. 


Using magnesium citrate to alkalise

Magnesium citrate makes a great choice of alkalising supplement because it combines the numerous beneficial actions of a magnesium supplement with the alkalising actions of citrate.

I won’t go through the benefits of magnesium supplementation for people with CKD here because there are a lot of them! But if you’re interested, have a look at our blog post:

Magnesium citrate is a well-absorbed form of magnesium supplement. After being dissolved in water, citrate carries the magnesium quickly and safely through the acidic environment of the stomach to the intestines where magnesium can be freed easily from the citrate carrier allowing the magnesium to be easily absorbed into the bloodstream.

The citrate portion of magnesium citrate is then available to bind to the acidic hydrogen ions in the blood, converting them to carbon dioxide and water for easy excretion.

Citrates vs Sodium Bicarbonate

Bicarbonate is one of the major chemical buffers used by the body to adjust pH, and sodium bicarbonate can be used as a supplement to alkalise the body and is frequently recommended as an alkalising supplement for people with CKD however it does come with some potential problems. 

Bicarbonate has an alkalising effect in the digestive tract, neutralising stomach acid and altering digestion. This can trigger unpleasant side effects such as diarrhoea, reflux, gas and bloating as well as impacting on the breakdown of food and absorption of vitamins and minerals from food and supplements.

Magnesium citrate does not have an alkalising effect until it is digested and absorbed and therefore has no negative effects on digestion. This makes mineral citrates the better alkalising choice for some people. 

But, Mineral citrates may not be for everyone

Magnesium citrate is typically the best form of alkalising mineral citrate for people with an eGFR above 35. This is because, in later stages of kidney disease (those with an eGFR below 35), high doses of magnesium may need to be avoided because the kidneys are responsible for the excretion of magnesium so as kidney function declines, magnesium levels may become too high.

For people with an eGFR below 35, sodium bicarbonate is recommended as an alkalising agent. 

Don’t forget to discuss any new supplements with your health care provider before starting on them to ensure it is appropriate for your use. Magnesium does interact with some medications which is another reason to get professional advice before taking it. 

Final Words

So there you have it, hopefully, now you have a better understanding of the importance of ensuring your body maintains an alkaline environment and the benefits of using magnesium citrate to support your body’s acid-base balance. And don’t forget you will also be reaping the numerous benefits of magnesium supplementation when you use magnesium citrate to alkalise. 

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