Oxalate Sensitivity - Where does it come from and how to fix it??

There would be a great injustice if we didn't talk about oxalate sensitivity in our healing journey. Far more people suffer from oxalate sensitivity, causing agonizing symptoms, without them even realizing it.

One of the very first things I do when bombarded with questions on a particular topic (this time oxalates)

I look at where it fits into the "Cycle of Illness". Genes? Mitochondria (cell) metabolism? Methylation? Gut health?? And then try to figure out what came first - the chicken or the egg? It can take some time looking at it from different angles before a clear picture starts to emerge.

What are Oxalates?

Oxalates are a nutrient called oxalate or oxalic acid, and are a naturally occurring compound in plants like leafy greens, legumes, and most other plant foods.

Our cells need these plant foods in order to keep our bodies healthy. Plant foods directly impact a process called Cellular Respiration. Cellular respiration is a series of chemical reactions that break down glucose to produce ATP, which may be used as energy to power many reactions throughout the body.

There are three main steps of cellular respiration: glycolysis, the citric acid cycle,

and oxidative phosphorylation

Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer.[2] When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day.[3] It is also a precursor to DNA and RNA, and is used as a coenzyme.

So as you can see by the diagram above, Glucose gets turned into ATP for the body. The plant needs ATP to create light energy or glucose. Our body takes the glucose from the plants and turns it into energy. Do you see the direct relationship between our cells and plants?

Even though plant foods are essential for our health, for some folks, however, adding a mere morsel of plant foods to their diets causes terrible symptoms. But why??' Down the rabbit hole I go....

Like many things in life - moderation is the key. Our body does have the ability to manage mild levels of oxalates in our body. But if oxalate levels build up too high, we will suffer consequences in our health by damaging cells, organs, systems, and further throwing off methylation.

Oxalates aren’t something most doctors are even aware of, let alone on their radar as potential protagonists. There is one quick way to know - If you suffer from horrendous, terrible, very bad, no good kidney stones. That's one very easy way to know if you have oxalate sensitivity; but its not always that simple.

Why do oxalates levels rise to toxic levels and cause us harm?

Leaky Gut. One of the main reasons oxalates become a problem, is that they leak in through a leaky gut when the gut is significantly damaged - and most of us have a leaky gut of some kind.

The modern western diet. The caloric dense, nutrient deficient, chemical laden, gut busting western diet is another notorious cause of gut dysbiosis and damage - resulting in leaky gut, and more and more people are developing oxalate-related issues because of it.

Genes. While there are some rare, genetic causes for having high oxalates, the vast majority of people with oxalate problems cannot blame it on their genes. (Not exactly anyway.)

Gall Bladder Issues & Poor Digestion. A poor functioning gallbladder is the NUMBER ONE REASON we develop oxalate issues. And a healthy gallbladder is necessary to digesting food, and proper methylation is essential for a healthy gallbladder.

Those suffering from recurring issues of candida, bacterial overgrowths, infections, parasites, etc. tend to have more prevalent issues with oxalates - why? Because the gallbladder and its bile is what keeps the gut microbiome in check. Its what detoxes the gut! If you don't have a healthy gallbladder it CAN NOT do this. So you can see where the Gallbladder becomes essential to our oxalate battle.

The oxalate issue and digestion issues were discovered when doctors and scientists noticed a connection after bariatric surgery. To illustrate the connection between gut dysfunction and oxalates, they startd by looking at how oxalate levels rise after bariatric surgery. Research has showed that individuals who compromised their upper GI tract with surgery develop hyperoxaluria – (excess oxalates in the blood and urine).1 The relationship became very clear. When we damage the stomach and gallbladder, it begins to impair digestion. The more digestion becomes dysfunctional, the more oxalate problems develop. Simple as that.

As I showed in previousvidoes andpapers, digestion should stimulate the release of bile from the gall bladder allowing us to digest fats in our diet. The problem is that many people suffer from terrible gallbladder function, and gallbladder surgery is still one of the most common surgeries in America.

It’s the bile from the gallbladder that helps us fend off the negative effects of oxalates. Without bile release from a healthy gallbladder, oxalates are going to become a problem, esp. for those with chronic gut or methylation problems.

Bile acts like soap and soap chops fat globules into tiny balls called micelles – a chemical property we need in order to absorb all those healthy Omega 3 fats and fat-soluble vitamins like A, D, E, and K. When the gallbladder is working properly the fat in our diet is absorbed in the small intestine and the oxalates in our meal form a compound with calcium called calcium-oxalate which we cannot absorb.5

In this way bile helps us absorb the fats we need and pass the oxalates in the stool so they don’t cause problems (Figure 4.1). Normally our body will not absorb all calcium from out diet. The undigested calcium is needed to bind with the oxalates in the gut which helps us to rid our body of this toxic molecule.

However the same cannot be said when the gallbladder system begins to malfunction.

When we stop releasing bile, whether it is from stomach dysfunction, taurine deficiency, or some other health problem (like having the gallbladder removed surgically), we will start to absorb more oxalates.6 This occurs because without bile release, we cannot absorb fats. Since the fats are floating down the small intestine without being absorbed, they begin to bind with all the calcium.

Remember when I said that calcium is required to bind with the oxalate in order to neutralize it?

Well when the fat isn’t digested then the calcium gets attached to the fats instead of the oxalate. This causes us to poop out all our healthy fats and our calcium, leading to significant nutritional and health problems down the road like osteoporosis and inflammatory diseases. When we do not absorb fats properly there is no calcium left to bind to the oxalates, and we end up absorbing high amounts of oxalates. As you will see, this will cause problems in other parts of our body.

What are the Genes or SNPs involved?

When speaking to doctors we often hear - "Just because we have the gene, doesn't mean its affecting us." That's true - its called Geno-type VS Phenotype.

- Geno-type is the genes we were given.

- Phenotype is the direct expression of that gene that results in symptoms.

However, if you have the gene and all the symptoms that go with it - tends to lead one to believe its OUR PHENOTYPE! And no one will know that better than you!!

However, please understand that many of the following genes/SNPs we will talk about are either;

- directly a part of methylation

- or indirectly affect methylation

Now folks tend to get really excited and really bummed out when they find out about their genes or SNPs.

Some get excited because they received validation. While others may look at a particular gene and get bummed because they believe they're stuck with the hand they were dealt and nothing can be done.

Thats probably the hardest part about trying to help folks in their healing journey. Overcoming the mindset that they're just stuck - its their destity to suffer. However, just because we have these genes, they may be our tendancy, but they are not our destiny!!! This idea is absolutely critical to understand because what we believe becomes our reality. But also because the environment inside the body, the environment that your cells live in - that DOES dictate your health and genetic expression; but we we have the power to change that environment!! We can change that environment and fine tune our genetic expression to keep us at our healthiest selves. And if we have the power to optimize our genes, that means we can HEAL IT!!

So lets get into it...

In other words - as we talk about oxalate issues (and low sulfate problems) we are really talking about an environmental issue inside the body. And lucky for us,

Oxalates create biochemical problems that make methylation issues worse. In the illustration above, oxalates impact the Methionine cycle (far right) and the entire process that stems downward from it. This is called Transulfuration (or Phase II).

This illustration is showing the Methionine cycle and and you have remethylation which goes around the methionine cycle again, and then the transulfuration pathway that stems downward. Note the word... tranSULFURation.

With oxalate issues also comes low sulfate (form of sulfur) problems. Since oxalate problems and sulfate problems go hand-in-hand, the genes most effected will be the SULT gene and other related pathways.

DIAGRAM 1: TRANSULFERATION PROCESS

The sulfate molecule is key in order for the liver to perform the daily task of detoxification.

If sulfate levels drop, then the body cannot use the SULT pathway to detoxify. Instead it will be forced to use other pathways such as NAT2, ALDH, COMT, GSH, GSS, UGT, and SOUX . However, a heavy demand is going to be put on these other detox pathways, and they are already genetically hampered.

When we consider these other detoxification gene SNPs (Nat2, ALDH, COMT, GSH, GSS,UGT, SUOX) we can begin to see that a lack of sulfate molecules can have a broad negative impact on all of our detoxification pathways.

(slides pulled from Genes n SNPs slides which details genes within methylation cycles.)

Even without an oxalate issue people with SULT SNPs have slowed detoxification and are going to be more sensitive to toxins, hormones, xenobiotics, and heavy metals.

Individuals with the SULT SNPs will be:

- Sensitive to low s sulfate levels. (symptoms will flare, and detox will drop)

- Further slow methylation & detoxification

- Sensitive to food colorings and additives in processed foods. These are phenols which

will further slow down the SULT pathway

Without realizing it, people are literally clogging/slowing down/halting their SULT pathway with toxins, oxalates, food colorings and more. We are literally shooting ourselves in the foot or sabotaging our healing path.

MTHFR Mutation. We already know that MTHFR gene is the master methylation gene. The transulfuration pathways are a big part of the methylation cycles. So adding in a MTHFR gene mutation means this process is already pretty slow, add in the SULT and it gets even slower. So if you're eating a lot of oxalates on top of that, with a slowed transulfuration pathway - you're going to slow it down further cuz you're wiping out what little sulfate you had. Its going to bite you in the butt and keep you in a negative feedback loop. You can stabilize or level it - but you wont heal.

This is generally when I say to water fast and clear out your intestinal tract. Let the body first finish detoxing whats already stuck in it, and get out any food leaking in through the damaged gut. Then we rebuild. This initial step can take some type depending on how slow your methylation has become.

Taking in oxalates and ignoring what you're body is trying to tell you can create:

- Further methylation issues,

- High homocysteine

- Developmental disorders

- Gallbladder dysfunction

- Hormone Imbalances

- Excess Inflammation

In individuals with an impaired methylation cycle this can provoke methylation issues such as high homocysteine, developmental disorders, gallbladder dysfunction, hormone imbalances, excess inflammation, poor growth and to name but a few. So with oxalate issues and the biochemical chaos it creates, a great deal of stress is placed on the methylation cycle.

What else inhibits Sulfation process

Many factors influence the activity of sulfate conjugation. For example, a diet low in methionine and cysteine has been shown to reduce sulfation. This is because they can be used as building blocks to make sulfate.

When there is more than one compound that is transformed by a single enzyme, there is what is called competative inhibition. In this case one compound is unable to be transformed due to the competition of the other compound. The compound being transformed will bind the active site of the enzyme and the other compound simply can't use it now. If aperson is around a lot of essential oils that have phenols and eating a lot of high phenol foods they may end up without enough sulfates for sulfation. They might run out of enzymes. If the person has a high oxalate problem, they will surely be running out of sulfates if the hyperoxaluria (exogenous or endogenous caused) is not being treated and they will definitely be reacting to foods with oxalates and phenols in them as well as any essential oils or chemicals containing phenols that are floating through the air.

An increase in toxins from the environment or bacteria in the gut can also lead to what is called inhibition due to increased toxic load. I would not really call this inhibition, although researchers do, but it does decrease enzymes available. It is simply a case of using up available enzymes faster than they can be made. Bacteria and fungus such as the Candida yeast can cause decreaesed availabilty of sulfation enzymes.

One mechanism of inhibition is depletion of necessary cofactors. Sulfation is particulary susceptible to inhibition due to depletion of cofactors. There is a delicate balance of serum sulfate concentration. This relies on the absorption of inorganic sulfate, and it production from cysteine on one hand, and the elimination of sulfate by urinary excretion, and sulfation of low molecular weight substrates on the other hand.

Over a 24 hour period the serum sulfate levels in a person vary dramatically. It will decrease if fasting, or eating a lot of substances that are metabolized by sulfation (acetaminophen). A person excretes about 20-25 millimoles of sulfate in a 24 hour period. Sulfate reserves must be continuously maintained by dietary intake of sulfur-containing amino acids or inorganic sulfate. Both will increase serum sulfate levels.

When sulfation is inhibited a person is unable to detoxify, and elminate tylenol as well as adrenaline and dopamine from the brain.

• Non-steroidal anti-inflammatory drugs (e.g. aspirin)

• Tartrazine (yellow food dye)

What induces Sulfation process

Anything that will enhance production of cysteine (building block to make sulfate) will help induce sulfation.

N-acetyl cysteine (NAC) is a supplement that can be used as a substrate to ultimately make sulfate. It involves multiple steps needing multiple enzymes as well as iron, tyrosine, B6, B2 and molybdenum.

I have included a diagram above and again here, that shows the oxidative, and non-oxidative pathways for cysteine to become sulfate.

Be careful about taking any product such as NAC that is a chelator as they can chelate out toxins such as mercury or mycotoxins and if you take too high a dose or dose is sporadic,

it may cause symptoms from pulling out the toxins in an unconscious and haphazard manner.

Not shown on this chart is the production of hydrogen sulfide (toxic in excess, necessary in small amounts) when homocysteine is changed into cystathionine and again when cystathionine is changed into cysteine.

The signaling molecule, hydrogen sulfide travels through bodily tissue by simple diffusion, so it easily moves around. Usually involved in blood vessel relaxation, neuromodulation, angiogenesis, regulation of inflammatory response, insulin release, energy metabolism and cardioprotection; it can also contains inorganic sulfur and can be oxidized as a source for sulfate. The process of clearing excess hydrogen sulfide both is protective to the body while supplying the much needed sulfate. The mitochondrial sulfide oxidation pathway couples sulfide catabolism to oxidative phosphorylation, making sulfide an inorganic substrate for the human electron transfer chain (mitochondria).

As you can see sulfite oxidase (encoded by the nuclear SUOX gene) catalyzes the final step of cysteine catabolism thereby oxidizing sulfite to sulfate.

Sources of Sulfur to make Sulfate

(remember SUOX makes sulfur to sulfate --> SULT uses sulfate in Transulfuration process)

FOOD IS ALWAYS THE BEST MEDICINE

Cruciferous vegetables such as broccoli, kale, cauliflower, cabbage, brussel sprouts, bok choy turnip, radish, kohlrabi and mustard are a source of sulfur as are the Alliums such as garlic, scallions, leeks chives, shallots and onions. These plants contain sulfur containing constituents such as glucosinolates, sulforaphane, isothiocyanates.

Amino acids found in proteins such as methionine and cysteine. Sufur rich animal foods include beef, chicken, lamb, turkey, duck, pork, milk, cheese and eggs.

The majority of sulfur is obtained from amino acids.

Sulfur containing molecules found in the body include:

• B vitamins biotin, Pantothenine (B5) and Thiamin (B1)

• Methionine,

• S-adenosylmethionine (SAMe)

• Homocysteine

• Cycsteine

• Metallothioneine

• Taurine

• Glutathione

• Alpha lipoic acid (AKA thioctic acid)

Nutritional Supplements Containing Sulfur

Supplements that contain sulfur include:

• Alpha lipoic acid

• Chondroitin sulfate

• Glucosamine sulfate

• Glutathione

• Indole-3 -carbinol

• Methylsulfonyl-methane

• Methionine

• N-acetyl cysteine

• Taurine

Using Supplements And Food To Supply Sulfur

For people with oxalate issues, they need to add sulfur or sulfate in the forms of supplements or baths slowly, as it will help remove the oxalates and can bring on a painful crisis as the oxalates are moved around. These people need to start slowly.

The issue with useing amino acids, or supplements such as NAC, that supply sulfur compounds, is that the body needs to change the sulfur first into sulfite through a reaction such as sulfoxidation and then using sulfite oxidase, change the sulfite into sulfate. This step needs molybdenum, B-12, B-2, manganese, boron and strontium for it to take place. Another way to supply sulfate is through Epsom salt baths which contain magensium sulfate.

Inducers

• NAC - remember this is a chelator and needs to be used cautiously if someone has toxins that may be chelated out of cells and therefore cause symptoms.

• Resveratrol is a substrate for sulfation as well as glucuronidation. Reseveratrol induces UGT1A1 transcription.

Substrates that may be used for sulfation and sulfoxidation: Sulfur containing foods in general, NAC, methionine molybdenum, B2 and B6, vitamin A, and adequate protein. Epsom salts are a great way to get ready made sulfate into the body by soaking in an Epsom salt batH -

**(JUST BE CAREFUL! If you have the SUOX gene, you may not tolerate this - Plus the salt can make you retain water and thus more toxins. )

This bypasses the need to make sulfate if someone is low in sulfate.

Foods with Oxalates

Oxalates are found in many common foods such as caffeine, chocolate, nuts and seeds, and many varieties of fruits and vegetables.

There are many Low Oxalate FB groups out there that can help you with Oxalate foods. Heres a FB Page called The Low Oxalate

https://www.facebook.com/groups/135981539816730

Oxalates are also found in the connective tissue of animals. So eating animal proteins will also raise oxalate levels. When we eat our kale salads or drink our spinach smoothies we are getting the nutrients and antioxidants in those plants; but we are also getting all the oxalates. Some people who juice every day don’t may be overdosing on oxalates. But don’t despair and think I am saying that these foods are bad for you or you can't juice.

Foods that contain oxalates are some of the healthiest foods we can eat – spinach, blueberries, kale, etc. As long as our digestion is working properly, producing stomach acid and releasing enzymes and bile, the oxalates in food are not a problem.

As long as our gallbladder is working well, we can eat food with oxalates and have no worries that we will develop an oxalate problem. The problem with oxalates arises because we don’t exactly have healthy gallbladders in this country.

Calcium and Kidney Problems

One of the big problems with oxalates is that they cause imbalances in the kidneys, bones and liver. The kidneys are especially sensitive to oxalates, where they have a tendency to cause kidney stones. I have personally suffered greatly with kidney stones, and its absolutely terrible. Childbirth has NOTHING on a kidney stone.

And not surprisingly, the latest research on kidney stones points clearly to problems in the gut and methylation as the root cause (because it affects liver and gallbladder. Please see previous paper on Gallbladder and methylation) Taking a closer look at the biochemical research we can see clearly how oxalates, and by extension gut and methylation problems, are the most common cause of kidney stone suffering. (Which is why drinking too much caffeinated soda also causes kidney stones)

From research published in the New England Journal of Medicine going back forty years, we have the first indications that gut problems can cause oxalate issues in the kidney. Researchers investigating ulcerative colitis patients found that after sections of the ileum had been surgically removed that many individuals developed hyperoxaluria (too much oxalate), a known risk factor for stone formation.7 A later study published in 2010 highlighted the fact that almost 75% of all kidney stones are in fact calcium-oxalate stones, further cementing the connection between kidney damage and oxalate levels.6 What both these studies confirm is that most people in the USA who have a kidney stone are actually suffering from an oxalate problem that starts either in the gut or methylation (which leads to gut issues - the chicken or the egg phenomenon)!

In a more recent study released in 2015 researchers confirmed that not only do oxalates cause most kidney stones, they also play a role in robbing the body of calcium leading to bone degeneration and osteoporosis.8 This illustrates that we don’t just suffer oxalate problems in the gut and the kidney, they have effects on our bones as well! When the gut cannot provide an adequate level of calcium for the rest of the body, the bones are broken down to release calcium into the bloodstream. If this happens long enough, bone loss and osteoporosis is the result. Too bad no one tells you that when you get your gallbladder removed! This is why I'm always asking folks if they have thier gallbladder, and adamant that patients keep their gallbladder whenever possible. (Taurine can break down gallbladder stones, and turn sludge back intothe dish soap bile you need. And choline is used by the gallbladder to protect the inside of the gallbladder and can calm a stinging, angry gallbladder)

Many readers have probably heard someone say that “excess” calcium can give you kidney stones. But we cannot blame calcium when the problem is caused by oxalates. Oxalates hurt the kidney and other tissues because they are one of the most insoluble compounds in the body.9 This means if levels rise too high then oxalates will form crystals and will be almost impossible for the body to dissolve. They can deposit in the brain, lungs, blood vessels, joints and bones causing pain and dysfunction throughout our body.10-13

Forming oxalate crystals inside the body can be a hidden source of pain and dysfunction in dozens of chronic health problems ranging from autism to fibromyalgia to vulvodynia and more.

Trick question, If calcium-oxalate stones are what cause most kidney stones, should you avoid calcium in your diet? The answer is No! You need More calcium, not less, if you want to prevent oxalate stones from forming.

While this sounds completely contradictory, the body has a genius reason for why it does this. Research has proven that eating more calcium in the diet will actually prevent calcium-oxalate stones by binding up more of the oxalates in your gut.14 This apparent paradox is solved by remembering that oxalate kidney stones are really just a gut problem that shows up as a problem the kidney. In other words when you fix the gut, you fix the kidney’s oxalate problem. In order to make all this happen, you also have to heal methylation.

When faced with the problem of oxalates leaking into the gut, one of the best strategies is to take calcium-citrate with meals (if possible). This type of calcium does two things. First, calcium-citrate releases its calcium quickly into the gut, helping to bind up the extra oxalates floating around.

And second the citrate helps to prevent the calcium and the oxalate from binding inside the kidney.15, 16 THATS SUPER IMPORTANT IF YO HAVE KIDNEY ISSUES AND OXALATE ISSUES!!

I wish I could stop here and say that is all the damage that oxalates can do to our body, but that would fall short of capturing the full story. In addition to robbing us of calcium, healthy fats and fat-soluble vitamins, and causing kidney stones, oxalates also deplete us of sulfate and vitamin B6.

These two vitamins are incredibly powerful and are absolutely necessary for our health and survival.

Diet and Supplement Recommendations

Now that you have some idea of the toxicity of oxalates its time to look at how to fix the issue. I will share with you some helpful concepts for protecting your body from the toxic burden of oxalates. The good news is that treating oxalate problems can be healed.

can also help gastro-paralysis.

For more help on healing oxalate issues, you can contact Dr. Rostenberg at Red Mountain Natural Medicine today. Phone 208-322-7755. Email redmountainclinic@gmail.com. Website http://www.redmountainclinic.com

By studying the current peer-reviewed research, Dr. Rostenberg has discovered powerful, natural strategies to optimize gut and methylation function to heal the body. He can help you uncover the genetic or root causes of your health problem and find a natural solution! If you would like help balancing your oxalate levels to improve your methylation cycle and reduce/eliminate your symptoms, please contact Dr. Rostenberg

Love and Light,

Happy Healing

REFERENC

1. Kumar R, Lieske JC, Collazo-Clavell ML, et al. Fat malabsorption and increased intestinal oxalate absorption are common after Roux-en-Y gastric bypass surgery. Surgery. 2011 May;149(5):654-61.

2. Low Oxalate Diet May Help Prevent Kidney Stones. University of Pittsburg Medical Center Web Site. http://www.upmc.com/patients-visitors/education/nutrition/pages/low-oxalate-diet.aspx. Accessed on 10/17/2015.

3. Nguyen QV, Kälin A, Drouve U, et al. Sensitivity to meat protein intake and hyperoxaluria in idiopathic calcium stone formers. Kidney Int. 2001 Jun;59(6):2273-81.

4. Common Surgical Procedures. The University of Chicago Medicine web site. http://www.uchospitals.edu/online-library/content=P01392. Accessed on November 27, 2015.

5. Marengo SR, Romani AM. Oxalate in renal stone disease: the terminal metabolite that just won’t go away. Nat Clin Pract Nephrol. 2008 Jul;4(7):368-77.

6. Evan AP. Physiopathology and etiology of stone formation in the kidney and the urinary tract. Pediatr Nephrol. 2010 May; 25(5): 831–841.

7. Dobbins JW, Binder HJ. Importance of the colon in enteric hyperoxaluria. N Engl J Med. 1977 Feb 10;296(6):298-301.

8. Yiu AJ, Callaghan D, Sultana R, et al. Vascular Calcification and Stone Disease: A New Look towards the Mechanism. J Cardiovasc Dev Dis. 2015;2(3):141-164.

9. Shaw, W. Oxalates Control is a Major New Factor in Autism Therapy. Great Plains Laboratory. http://www.greatplainslaboratory.com/home/eng/oxalates.asp. Accessed on November 27, 2015.

10. Ghio AJ, Roggli VL, Kennedy TP, et al. Calcium oxalate and iron accumulation in sarcoidosis. Sarcoidosis Vasc Diffuse Lung Dis. 2000 Jun;17(2):140-50.

11. Ott SM, Andress DL, Sherrard DJ. Bone oxalate in a long-term hemodialysis patient who ingested high doses of vitamin C. Am J Kidney Dis. 1986 Dec;8(6):450-4.

12. Hall BM, Walsh JC, Horvath JS, et al. Peripheral neuropathy complicating primary hyperoxaluria. J Neurol Sci. 1976 Oct;29(2-4):343-9.

13. Sahin G, Acikalin MF, Yalcin AU. Erythropoietin resistance as a result of oxalosis in bone marrow. Clin Nephrol. 2005 May;63(5):402-4.

14. Hess B, Jost C, Zipperle L, et al. High-calcium intake abolishes hyperoxaluria and reduces urinary crystallization during a 20-fold normal oxalate load in humans. Nephrol Dial Transplant. 1998 Sep;13(9):2241-7.

15. Berg, C. Alkaline citrate in prevention of recurrent calcium oxalate stones. Scand J Urol Nephrol Suppl. 1990;130:1-83.

16. Ohana E, Shcheynikov N, Moe OW, et al. SLC26A6 and NaDC-1 transporters interact to regulate oxalate and citrate homeostasis. J Am Soc Nephrol. 2013 Oct; 24(10): 1617–1626.