Low oxalate diet
Oxalate ( Ethanedioate ),
sometimes abbreviated as ox
when a ligand,
Either name is often used for derivatives, such as
disodium oxalate, or an ester of oxalic acid (such as
dimethyl oxalate, Many metal ions form insoluble
precipitates with oxalate, a prominent example being
calcium oxalate, the primary constituent of the most common kind
of kidney stones.
Oxalic acid (chemical formula HOOC-COOH) is a strong
organic acid which is widely distributed in nature in both
plants and animals. However, plants contain more than
animals. The name comes from the plant Oxalis (wood
sorrel) from which it was first isolated.
Oxalic acid has the ability to form a strong bond with various
minerals, such as sodium, potassium, magnesium, and calcium.
When this occurs, the compounds formed are usually
referred to as oxalate salts.
Thus, “oxalate” usually refers to a salt of oxalic acid, one of which is calcium oxalate.
minerals, such as sodium, potassium, magnesium, and calcium.
When this occurs, the compounds formed are usually
referred to as oxalate salts.
Thus, “oxalate” usually refers to a salt of oxalic acid, one of which is calcium oxalate.
Although both sodium and potassium oxalate salts are
water soluble, calcium oxalate is practically insoluble,
which is why calcium oxalate, when present in high
enough levels, has the propensity to precipitate (or
solidify) in the kidneys or in the urinary tract to form
calcium oxalate crystals.
water soluble, calcium oxalate is practically insoluble,
which is why calcium oxalate, when present in high
enough levels, has the propensity to precipitate (or
solidify) in the kidneys or in the urinary tract to form
calcium oxalate crystals.
Calcium oxalate crystals, in turn, contribute to the
formation of kidney stones. Approximately 80% of
all kidney stones are composed predominantly of
calcium oxalate. For reasons not yet fully
understood, women have a much lower incidence of
kidney stones than men.
formation of kidney stones. Approximately 80% of
all kidney stones are composed predominantly of
calcium oxalate. For reasons not yet fully
understood, women have a much lower incidence of
kidney stones than men.
Thus oxalate is a very simple sort of molecule that
links up with calcium and then crystalizes under
some conditions, including when it encounters
damaged tissues.
The crystals formed this way can be quite
irritating and painful to tissues where they form,
causing or increasing inflammation.
links up with calcium and then crystalizes under
some conditions, including when it encounters
damaged tissues.
The crystals formed this way can be quite
irritating and painful to tissues where they form,
causing or increasing inflammation.
These crystals can be especially painful if they lodge
themselves in places where they get in the way of the
movement of other things through tight places.
These physical issues are easy to understand, but
there are still many secrets nature has about how oxalates
interact with other parts of the metabolism.
themselves in places where they get in the way of the
movement of other things through tight places.
These physical issues are easy to understand, but
there are still many secrets nature has about how oxalates
interact with other parts of the metabolism.
Where do oxalates come from?
Oxalates are present in a lot of plants and fruit that we
eat and in virtually all seeds and nuts.
Ordinarily, the gut will not absorb much of the
oxalate from the diet, and the oxalate will be
metabolized by the flora or just leave the body with the stool.
Under other conditions, a lot of the dietary oxalate is absorbed,
Oxalates are present in a lot of plants and fruit that we
eat and in virtually all seeds and nuts.
Ordinarily, the gut will not absorb much of the
oxalate from the diet, and the oxalate will be
metabolized by the flora or just leave the body with the stool.
Under other conditions, a lot of the dietary oxalate is absorbed,
Over absorption is far more likely to occur when the
tight junctions between the cells which line the gut open up
and let molecules pass through between the cells in a
condition called the "leaky gut" which is similar to a
condition in the bladder with open junctions called the "leaky bladder".
Is oxalate found in most foods?
Most foods do not contain significant amounts of oxalate.
The primary sources of dietary oxalate are plants and plant
products. Although the physiological role of oxalate in
plants is not clearly understood, it is well established that a
number of plants have the ability to synthesize oxalate.
Seeds and leafy plants related to spinach and rhubarb contain the most oxalate.
Most foods do not contain significant amounts of oxalate.
The primary sources of dietary oxalate are plants and plant
products. Although the physiological role of oxalate in
plants is not clearly understood, it is well established that a
number of plants have the ability to synthesize oxalate.
Seeds and leafy plants related to spinach and rhubarb contain the most oxalate.
Other edible plants that contain significant concentrations of oxalate include—in decreasing order— (carambola), black pepper, parsley, poppy seed, amaranth, spinach, chard, beets,
when drinking milk with a rhubarb dessert is caused by precipitation of calcium oxalate , chocolate, most nuts, most berries , fishtail palms , New Zealand spinach and beans .
The “gritty mouth” feeling one experiences .
The calcium is abstracted from the casein in dairy products.
Leaves of the tea plant contain among the greatest measured concentrations of oxalic acid relative to other plants. However the infusion beverage typically contains only low to moderate amounts of oxalic acid per serving, due to the small mass of leaves used for brewing.
After the substance crosses the intestinal cell, it can leave the
cell to join the blood by means of a different set of
transporters that are on the blood or "exit" side. With this kind
of regulation coming from both sides of the cell, when the
body recognizes that you don't need more of a substance from food, the cell won't let more of that substance cross through.
The body obviously loses that regulation when substances are absorbed through the "leaky" junctions between cells.
Oxalates are just one of the substances where this is a
problem, but whenever more oxalates are absorbed
like this, the result may be high levels of oxalates in
blood and urine and in tissues. Scientists call the high
levels in urine hyperoxaluria
problem, but whenever more oxalates are absorbed
like this, the result may be high levels of oxalates in
blood and urine and in tissues. Scientists call the high
levels in urine hyperoxaluria
Eating food high in oxalates is not the only way to get
high oxalates systemically. Our bodies make oxalates
on their own, especially when certain enzymes aren't
balanced in their activity. Normally, when oxalates are in
the gut, they may encounter particular species of
bacteria which will digest them and turn them into
something else that isn't so irritating.
This system of microbial digestion may be why the body
seems to purposefully route excess oxalate from the rest
of the body to the gut.
the very microbes we need to do this digesting of oxalates for
us are subject to being killed by antibiotics in common use.
Even if there was no exposure to antibiotics, these microbes
might not have colonized yet in very young children, for it does
not tend to be in breast milk, but must be picked up from the environment.
seems to purposefully route excess oxalate from the rest
of the body to the gut.
the very microbes we need to do this digesting of oxalates for
us are subject to being killed by antibiotics in common use.
Even if there was no exposure to antibiotics, these microbes
might not have colonized yet in very young children, for it does
not tend to be in breast milk, but must be picked up from the environment.
Lactobacillus acidophilus is an oxalate-eating species, but
when oxalates are in excess, lactobacillus can be killed off.
a probiotic formulation of a bacteria called oxalobacter
formigenes that helps digest oxalates even better than
lactobacillus is under development for patients with
hyperoxaluria and related conditions.
when oxalates are in excess, lactobacillus can be killed off.
a probiotic formulation of a bacteria called oxalobacter
formigenes that helps digest oxalates even better than
lactobacillus is under development for patients with
hyperoxaluria and related conditions.
What is the function of oxalates in the body?
There is a positive side to oxalates because they
help us manage calcium, but the management of
oxalates themselves will fall down when cells are
low in glutathione and also in oxidative stress.
Oxalates add to that oxidative stress.
There is a positive side to oxalates because they
help us manage calcium, but the management of
oxalates themselves will fall down when cells are
low in glutathione and also in oxidative stress.
Oxalates add to that oxidative stress.
Plants use oxalates to protect themselves from infection or from
being
eaten, as these crystals can tear up the mouths of the bugs that eat them,
but we haven't learned nearly enough about the positive side of oxalates in humans.
but some of studies said that a small dose of calcium oxalate is
enough to cause intense sensations of burning in the mouth and
throat, swelling, and choking that could last for up to two weeks,
We know a lot of negatives about oxalates,
eaten, as these crystals can tear up the mouths of the bugs that eat them,
but we haven't learned nearly enough about the positive side of oxalates in humans.
but some of studies said that a small dose of calcium oxalate is
enough to cause intense sensations of burning in the mouth and
throat, swelling, and choking that could last for up to two weeks,
We know a lot of negatives about oxalates,
Effects of over Ingestion: -
In greater doses it can cause severe digestive upset, breathing difficulties, coma or even death.
Recovery from severe oxalate poisoning is possible, but permanent liver and kidney damage may have occurred.
The stalks of plants in the Dieffenbachia genus produce the most severe oxalate reactions. The needle-like oxalate crystals produce pain and swelling when they contact lips, tongue, oral mucosa, conjunctiva, or skin.
Edema primary is due to direct trauma from the needle-like crystals and, to a lesser extent, by other plant toxins (e.g., bradykinins , enzymes).
Depending on the plant ingested,
In greater doses it can cause severe digestive upset, breathing difficulties, coma or even death.
Recovery from severe oxalate poisoning is possible, but permanent liver and kidney damage may have occurred.
The stalks of plants in the Dieffenbachia genus produce the most severe oxalate reactions. The needle-like oxalate crystals produce pain and swelling when they contact lips, tongue, oral mucosa, conjunctiva, or skin.
Edema primary is due to direct trauma from the needle-like crystals and, to a lesser extent, by other plant toxins (e.g., bradykinins , enzymes).
Depending on the plant ingested,
And you should know that :
The presence of Oxalobacter formigenes in the gut flora can prevent this.
Cadmium catalyzes the transformation of vitamin C into oxalic acid and can result from smoking heavily,
The presence of Oxalobacter formigenes in the gut flora can prevent this.
Cadmium catalyzes the transformation of vitamin C into oxalic acid and can result from smoking heavily,
Is the low oxalate diet difficult to follow, or impossible to stay on?
The list of foods that have been tested for levels of
oxalate is limited, though growing. However, with careful
food selection, a low oxalate diet which provides all the
needed nutrients and is reasonably varied can be followed.
The list of foods that have been tested for levels of
oxalate is limited, though growing. However, with careful
food selection, a low oxalate diet which provides all the
needed nutrients and is reasonably varied can be followed.
You must remember that :
with any lifestyle change you should cut back in moderation.
It is not reasonable to cut out fruits and vegetables from
your diet, as they provide so many important nutrients.
Many fruits and vegetables have low oxalate content and can
be regularly included in your diet .
It is important to know that :
Oxalate content of a single food group varies based
on the time of year, the type of soil it is grown in
and a host of other factors specific to the growing
conditions of the plant.
Does a person following the low oxalate diet need to completely
eliminate all oxalate for the diet to be effective?
Foods with only low levels of oxalate do not need to be completely eliminated. The propensity for the
consumption of a specific food to increase urinary
oxalate is a function of both A) The amount of oxalate in that food and B) The amount of oxalate which can be
absorbed from that food.
Foods with only low levels of oxalate do not need to be completely eliminated. The propensity for the
consumption of a specific food to increase urinary
oxalate is a function of both A) The amount of oxalate in that food and B) The amount of oxalate which can be
absorbed from that food.
Since dietary oxalate is not efficiently absorbed into the
body, the consumption of foods which provide low levels
of oxalate will not have a significant effect on the amount
of dietary oxalate which enters the body through the
gastrointestinal tract or on the amount of oxalate which
is excreted via the urine.
body, the consumption of foods which provide low levels
of oxalate will not have a significant effect on the amount
of dietary oxalate which enters the body through the
gastrointestinal tract or on the amount of oxalate which
is excreted via the urine.
Does drinking water (tap water, spring water, distilled water)
contain oxalate?
Water is not a dietary source of oxalate unless the
water has come in contact with high-oxalate plants
(e.g., water that high-oxalate plants have been cooked in).
Water is not a dietary source of oxalate unless the
water has come in contact with high-oxalate plants
(e.g., water that high-oxalate plants have been cooked in).
Hard water (which contains calcium and magnesium) is
likely to exert a beneficial effect with respect to oxalate
absorption because these minerals will tie up much of the
oxalate consumed in the diet within the gastrointestinal tract,
thereby decreasing oxalate absorption.
Less oxalate absorption translates to less oxalate gaining access
to various tissues within the body.
Is a low oxalate diet nutritionally inadequate?
There are certain nutrient intakes which could be
compromised in a low oxalate diet. For example, low
oxalate diets may provide lower levels of nutrients
which are found primarily in plant products, such as
vitamin C and folate. However, with wise food selections, an
individual can maintain a low oxalate diet and still consume
recommended levels of all key nutrients.
There are certain nutrient intakes which could be
compromised in a low oxalate diet. For example, low
oxalate diets may provide lower levels of nutrients
which are found primarily in plant products, such as
vitamin C and folate. However, with wise food selections, an
individual can maintain a low oxalate diet and still consume
recommended levels of all key nutrients.
Hyperoxaluria and kidney stones :
Hyperoxaluria, defined as excessive urinary oxalate, is a common
abnormal finding in patients with calcium oxalate kidney stones.
Some degree of excessive urinary oxalate is found in 20-30% of all patients with recurrent calcium oxalate stones.
A low-oxalate diet is for people who have calcium oxalate kidney stones is required.
Cutting back on high-oxalate foods and salt (sodium) and drinking plenty of water may help prevent kidney stones from forming.
Here are some important points to remember for patients have
hyperoxaluria :
• Drink plenty of fluids. Drink more than 8
cups of fluid every day. Your urine should be
as clear as water. If it isn’t, drink more fluids
• To prevent oxalate stones from forming,
limit oxalates to 40 to 50 mg per day. Use
the chart as a guide.
• Drink plenty of fluids. Drink more than 8
cups of fluid every day. Your urine should be
as clear as water. If it isn’t, drink more fluids
• To prevent oxalate stones from forming,
limit oxalates to 40 to 50 mg per day. Use
the chart as a guide.
• Low-oxalate foods have less than 2 mg of
oxalate per serving. You can eat as much of
these foods as you like.
• Moderate-oxalate foods have 2 to 6 mg
of oxalate per serving. You should eat no
more than three of these foods per day.
• High-oxalate foods have more than 7 mg
of oxalate per serving. Avoid these foods
Most oxalate is a waste product made by the body and
has no function in humans. The most common type of
kidney stone (80%) is made of calcium and oxalate.
Other sources of oxalate include:
• Eating foods high in oxalate
• Intestinal over absorption (patients who have had
intestinal resections due to inflammatory bowel
disease or gastric bypass surgery)
• Excess amounts of vitamin C (2,000 mg or more per
day; the excess converts to oxalate)
• Abnormalities of metabolism
One patient said that his urologist told him to cut back on oxalate. And
his cardiologist told him to eat plenty of vegetables and cut back on fats.
What you supposed him to do?
One doctor is worried about your heart (diabetes,
hypertension, etc), the other about your kidney stones.
If you are going to have a high oxalate food, such as a spinach salad, just limit the amount of spinach you are having.
Also, remember to flush out the extra oxalate you are
eating with a glass of water before and after your meal
One doctor is worried about your heart (diabetes,
hypertension, etc), the other about your kidney stones.
If you are going to have a high oxalate food, such as a spinach salad, just limit the amount of spinach you are having.
Also, remember to flush out the extra oxalate you are
eating with a glass of water before and after your meal
Another patient told you that he making calcium oxalate stones. Should
he cut back on dairy products too?”
your diet should have between 800 and 1,200 mg of calcium per day.
Eating a diet low in calcium is not advised. In fact,
studies have shown that eating low calcium diets will
increase calcium oxalate stone risk.
Oxalate and calcium bind together in your intestine
and leave the body together. If you eat a low calcium
diet then oxalate has no partner to leave the body
with. Oxalate will then be absorbed back into your
system leading to higher oxalate levels in your body.
your diet should have between 800 and 1,200 mg of calcium per day.
Eating a diet low in calcium is not advised. In fact,
studies have shown that eating low calcium diets will
increase calcium oxalate stone risk.
Oxalate and calcium bind together in your intestine
and leave the body together. If you eat a low calcium
diet then oxalate has no partner to leave the body
with. Oxalate will then be absorbed back into your
system leading to higher oxalate levels in your body.
What effect does bowel disease and/ or intestinal surgeries with
malabsorption have on oxalate levels?”
There is a definite correlation between patients who
suffer from bowel disease and malabsorption problems
and the formation of kidney stones. Their urine is
more acidic, citrate levels are lower, and oxalate levels
are much higher. If you have patient had an ileal resection
your patient may experience an increase in his oxalate levels due to malabsorption problems.
There is a definite correlation between patients who
suffer from bowel disease and malabsorption problems
and the formation of kidney stones. Their urine is
more acidic, citrate levels are lower, and oxalate levels
are much higher. If you have patient had an ileal resection
your patient may experience an increase in his oxalate levels due to malabsorption problems.
In bowel disease, fatty acids and bile that are normally
absorbed by the small intestine reach the colon.
When fatty acids and bile reach the colon, they can
damage the colon lining allowing oxalate to pass
through the damaged lining into the blood, and then
into the urine via the kidneys. When calcium and
oxalate are together in the kidney, they can bind together to
form crystals. These crystals can join together to form calcium oxalate kidney stones.
absorbed by the small intestine reach the colon.
When fatty acids and bile reach the colon, they can
damage the colon lining allowing oxalate to pass
through the damaged lining into the blood, and then
into the urine via the kidneys. When calcium and
oxalate are together in the kidney, they can bind together to
form crystals. These crystals can join together to form calcium oxalate kidney stones.
How is limiting fat intake will also help lower oxalate level?”
For patients who suffer from small bowel disease or
malabsorption, it is recommended that dietary fat
intake be controlled.
Excess fat will bind with calcium in food, thus leaving oxalate by itself to be reabsorbed by the colon and back into the blood stream. If too much oxalate is absorbed, it will combine with calcium in the kidney and can lead to calcium oxalate stones.
For patients who suffer from small bowel disease or
malabsorption, it is recommended that dietary fat
intake be controlled.
Excess fat will bind with calcium in food, thus leaving oxalate by itself to be reabsorbed by the colon and back into the blood stream. If too much oxalate is absorbed, it will combine with calcium in the kidney and can lead to calcium oxalate stones.
doctor may also prescribe a drug called
Cholestyramine. This is a drug taken at each meal
that binds fatty acids, bile and oxalate so all three
can leave the body.
Cholestyramine. This is a drug taken at each meal
that binds fatty acids, bile and oxalate so all three
can leave the body.
Does the low oxalate diet cause weight loss?
Foods restricted on the low oxalate diet include certain vegetables, fruits, whole grains, legumes, and nuts.
With the exception of nuts, these foods are not calorically dense (i.e., not high in fat). Thus, omitting high-oxalate foods should not necessarily lead to a reduction in caloric intake and subsequent weight loss.
Foods restricted on the low oxalate diet include certain vegetables, fruits, whole grains, legumes, and nuts.
With the exception of nuts, these foods are not calorically dense (i.e., not high in fat). Thus, omitting high-oxalate foods should not necessarily lead to a reduction in caloric intake and subsequent weight loss.
However, there is evidence that some people will
consume less calories when put on a restrictive
diet. Thus, the degree to which oxalate-containing
foods are restricted could partially dictate whether a
low oxalate diet is lower in calories than a diet not
restricted in oxalate-containing foods.
consume less calories when put on a restrictive
diet. Thus, the degree to which oxalate-containing
foods are restricted could partially dictate whether a
low oxalate diet is lower in calories than a diet not
restricted in oxalate-containing foods.
Does the low oxalate diet cause weight gain?
This would only be true if an individual compensates for
not eating certain fruits and vegetables, whole grains,
and legumes by eating significantly larger quantities than
normal of animal products such as meat, fish, poultry,
eggs, and dairy products. Otherwise, the low oxalate diet
should not lead to weight gain.
This would only be true if an individual compensates for
not eating certain fruits and vegetables, whole grains,
and legumes by eating significantly larger quantities than
normal of animal products such as meat, fish, poultry,
eggs, and dairy products. Otherwise, the low oxalate diet
should not lead to weight gain.
Does a low oxalate diet cause constipation?
There may be a possibility of constipation with a
low oxalate diet. Whole grains, legumes, fruits, and
vegetables are the best sources of fiber, an
important dietary component that aids regularity.
There may be a possibility of constipation with a
low oxalate diet. Whole grains, legumes, fruits, and
vegetables are the best sources of fiber, an
important dietary component that aids regularity.
Careful selection of foods on a low oxalate diet can
provide adequate fiber. Any food which provides at least
3 to 4 grams of fiber per serving would be considered an
excellent source (see chart).
To put the numbers in perspective, the recommendation
for total intake of dietary fiber is 25 to 35 grams per day.
provide adequate fiber. Any food which provides at least
3 to 4 grams of fiber per serving would be considered an
excellent source (see chart).
To put the numbers in perspective, the recommendation
for total intake of dietary fiber is 25 to 35 grams per day.
I am lactose intolerant. What can I do to increase my
dietary calcium?”
lactose intolerant is a common problem. You get calcium from other sources other than dairy products.
Cereals and orange juice are now fortified with calcium.
Your doctor may also tell you to take
calcium supplements with each meal to help bind
with oxalate so it cannot be reabsorbed back into your
bloodstream.
dietary calcium?”
lactose intolerant is a common problem. You get calcium from other sources other than dairy products.
Cereals and orange juice are now fortified with calcium.
Your doctor may also tell you to take
calcium supplements with each meal to help bind
with oxalate so it cannot be reabsorbed back into your
bloodstream.
Because I am lactose intolerant I eat a lot of soy
products. I heard that soy is high in oxalate.”
Recent research has concluded that the soy products
have high levels of oxalate and should be eaten in moderation.
Facts
• Oxalate is made in plants, animals and humans;
highest amounts appear in certain plant foods.
• The function of oxalate is to help plants dispose
of excess calcium.
• Our bodies have no use for oxalate and it is
excreted in the urine.
• Our bodies always have some varying degree
of oxalate.
• About 40-50% of oxalate is from outside sources
(foods you eat) and can be much higher on a high
oxalate diet.
• Oxalate is made in plants, animals and humans;
highest amounts appear in certain plant foods.
• The function of oxalate is to help plants dispose
of excess calcium.
• Our bodies have no use for oxalate and it is
excreted in the urine.
• Our bodies always have some varying degree
of oxalate.
• About 40-50% of oxalate is from outside sources
(foods you eat) and can be much higher on a high
oxalate diet.
Low oxalate bioavailability from black tea
Nutrition Research, Volume 27, Issue 5, May 2007, Pages 273-278 ,Michael Liebman, Shawnna Murphy
Result:
Both methods suggested that black tea–derived oxalate is of low bioavailability. At the present time, there is little overall support for the recommendation that kidney stone formers limit their intake of black tea
Nutrition Research, Volume 27, Issue 5, May 2007, Pages 273-278 ,Michael Liebman, Shawnna Murphy
Result:
Both methods suggested that black tea–derived oxalate is of low bioavailability. At the present time, there is little overall support for the recommendation that kidney stone formers limit their intake of black tea
Oxalate content of legumes, nuts, and grain-based flours
Journal of Food Composition and Analysis, Volume 18, Issue 7, November 2005, Pages 723-729, Weiwen Chai, Michael Liebman
Result :
Total oxalate varied greatly among the legumes tested, ranging from 4 to 80 mg/100 g of cooked weight. The range of total oxalate of the nuts tested was 42–469 mg/100 g. Total oxalate of analyzed flours ranged from 37 to 269 mg/100 g. The overall data suggested that most legumes, nuts, and flours are rich sources of oxalate
Journal of Food Composition and Analysis, Volume 18, Issue 7, November 2005, Pages 723-729, Weiwen Chai, Michael Liebman
Result :
Total oxalate varied greatly among the legumes tested, ranging from 4 to 80 mg/100 g of cooked weight. The range of total oxalate of the nuts tested was 42–469 mg/100 g. Total oxalate of analyzed flours ranged from 37 to 269 mg/100 g. The overall data suggested that most legumes, nuts, and flours are rich sources of oxalate
EFFECTS OF CALCIUM AND MAGNESIUM ON URINARY OXALATE EXCRETION AFTER
OXALATE LOADS Original Research Article
The Journal of Urology, Volume 163, Issue 5, May 2000, Pages 1565-1569, MICHAEL LIEBMAN, GREGGORY COSTA
Results:
Both the calcium carbonate and magnesium oxide treatments were associated with significantly lower load-derived oxalate levels at all time points within the initial 24-hour post-oxalate ingestion period compared with levels observed for the control treatment. There were no treatment effects on endogenous oxalate levels. The efficiency of oxalate absorption for the calcium carbonate (5.1%) and magnesium oxide (7.6%) treatments was significantly lower than that for the control treatment (13.5%).
The Journal of Urology, Volume 163, Issue 5, May 2000, Pages 1565-1569, MICHAEL LIEBMAN, GREGGORY COSTA
Results:
Both the calcium carbonate and magnesium oxide treatments were associated with significantly lower load-derived oxalate levels at all time points within the initial 24-hour post-oxalate ingestion period compared with levels observed for the control treatment. There were no treatment effects on endogenous oxalate levels. The efficiency of oxalate absorption for the calcium carbonate (5.1%) and magnesium oxide (7.6%) treatments was significantly lower than that for the control treatment (13.5%).
Effect of supplemental ascorbate and orange juice on urinary
oxalate Original Research Article
Nutrition Research, Volume 17, Issue 3, March 1997, Pages 415-425
Michael Liebman, Weiwen Chai, Ellen Harvey, Laura Boenisch
Abstract
The relationship between ascorbate intake, in supplemental form and naturally occurring in orange juice, and urinary oxalate was assessed in 6 healthy individuals. An experimental model which allowed a differentiation between endogenously- and exogenously-derived urinary oxalate was used. Twenty-four hour urine samples were collected the last day of baseline, supplemental ascorbate, and orange juice treatment periods. Oxalate load tests were administered the day following each experimental treatment. Oxalate loads consisted of 175 mg unlabeled and 18 mg 1, 2-13C2 oxalic acid. The orange juice treatment was associated with higher urinary excretion of endogenously-derived oxalate, citrate, and calcium, and a higher urinary pH. Since these urinary changes were not observed during the supplemental ascorbate period, the two sources of ascorbate differentially affected key urinary components which are related to calcium oxalate nephrolithiasis
Nutrition Research, Volume 17, Issue 3, March 1997, Pages 415-425
Michael Liebman, Weiwen Chai, Ellen Harvey, Laura Boenisch
Abstract
The relationship between ascorbate intake, in supplemental form and naturally occurring in orange juice, and urinary oxalate was assessed in 6 healthy individuals. An experimental model which allowed a differentiation between endogenously- and exogenously-derived urinary oxalate was used. Twenty-four hour urine samples were collected the last day of baseline, supplemental ascorbate, and orange juice treatment periods. Oxalate load tests were administered the day following each experimental treatment. Oxalate loads consisted of 175 mg unlabeled and 18 mg 1, 2-13C2 oxalic acid. The orange juice treatment was associated with higher urinary excretion of endogenously-derived oxalate, citrate, and calcium, and a higher urinary pH. Since these urinary changes were not observed during the supplemental ascorbate period, the two sources of ascorbate differentially affected key urinary components which are related to calcium oxalate nephrolithiasis
Olestra and fat inhibit oxalate absorption Original
Research Article
Nutrition Research, Volume 19, Issue 9, September 1999, Pages 1277-1285
Michael Liebman, Ellen Harvey, Weiwen Chai
Abstract
An experimental model which allowed a differentiation between endogenously-and exogenously-derived urinary oxalate was used to assess the effect of olestra ingestion on oxalate absorption and excretion. Seventeen healthy subjects participated in three oxalate load (OL) tests separated by at least one week and administered in the following order: OL-1, potato with fat (potato chips); OL-2, potato with olestra (olestra-containing potato chips); and OL-3, potato without fat (boiled potatoes). The three experimental treatments provided similar levels of carbohydrate. Oxalate loads, ingested immediately after consumption of the potato chips/boiled potatoes, consisted of 180 mg unlabeled oxalic acid and 14.3 mg 13C2-oxalic acid. Twenty-four hour urine samples were collected the day before the OL tests and timed urine samples were collected during the 48 h post-oxalate ingestion period. Endogenously-derived oxalate did not differ between treatments. Oxalate absorption for OL-1 (10.5 %) and OL-2 (10.2 %) was lower (P<0.05) than for OL-3 (13.2 %). The presence of fat or olestra depresses total oxalate absor
Nutrition Research, Volume 19, Issue 9, September 1999, Pages 1277-1285
Michael Liebman, Ellen Harvey, Weiwen Chai
Abstract
An experimental model which allowed a differentiation between endogenously-and exogenously-derived urinary oxalate was used to assess the effect of olestra ingestion on oxalate absorption and excretion. Seventeen healthy subjects participated in three oxalate load (OL) tests separated by at least one week and administered in the following order: OL-1, potato with fat (potato chips); OL-2, potato with olestra (olestra-containing potato chips); and OL-3, potato without fat (boiled potatoes). The three experimental treatments provided similar levels of carbohydrate. Oxalate loads, ingested immediately after consumption of the potato chips/boiled potatoes, consisted of 180 mg unlabeled oxalic acid and 14.3 mg 13C2-oxalic acid. Twenty-four hour urine samples were collected the day before the OL tests and timed urine samples were collected during the 48 h post-oxalate ingestion period. Endogenously-derived oxalate did not differ between treatments. Oxalate absorption for OL-1 (10.5 %) and OL-2 (10.2 %) was lower (P<0.05) than for OL-3 (13.2 %). The presence of fat or olestra depresses total oxalate absor
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