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Why
You Need Special Vitamins
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Kidney
Patients Have Special Vitamin Requirements
Vitamins are
very important to all metabolic functions of the body. Vitamins play a
part in controlling the body's ability to burn fat and sugar for energy,
and build proteins for growth. If vitamins are deficient, these reactions
are not properly coordinated, and may cause skin lesions, muscle weakness,
fatigue and nerve pain. These can be signs that vitamin supplementation
may be necessary.
Vitamins are
not produced by the human body. They must be taken in as food, or as vitamin
supplements. Healthy individuals who eat a well balanced diet including
grains, fresh fruit and vegetables, meat poultry and dairy products probably
do not need vitamin supplementation.
Kidney patients
need supplementation of some vitamins, but not others. In fact, supplementation
with some vitamins may have harmful effects.
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Why
Kidney Patients' Vitamin Requirements are Different
There are four
reasons why kidney patients have different vitamin requirements than healthy
individuals.
First, kidney
patients must eat a restricted diet. Their diet is restricted in dairy
products, fruits and vegetables. Fruits and vegetables are high in B vitamins,
but also high in potassium., so amounts eaten must be limited. A typical
diet for kidney patients is low in B complex Vitamins. Also, many patients
eat poorly due to loss of appetite or lack of motivation in preparing
a proper diet.
Second, kidney
disease may produce "uremic toxins" which interfere with absorption
or activity of some vitamins. Normally, uremic toxins are filtered by
the kidneys, but when the kidneys are deficient, they are present in higher
than normal amounts.
Third, drugs
taken for other illnesses may interfere with absorption or activity of
some Vitamins. For example, birth control pills or alcohol can interfere
with proper absorption, as can anti-cancer or anti-epileptic medications.
Fourth, dialysis
itself. Dialysis is a very important process in removing uremic toxins
that accumulate in the blood when the kidney fails. Still, the process
of circulating blood through a pore system means that some substances
that the body needs flow out and are lost or not needed, while other substances
that the body does not need, remain. The normal kidney regulates this
process more efficiently.
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Which
Vitamins are Important for The Kidney Patient, and which Vitamins are
Harmful?
Vitamin
A and Beta Carotene
Vitamin A and
beta carotene are important for good vision. For kidney patients, vitamin
A is not dialyzed off, and tends to be present in the body in higher than
normal amounts. Too much vitamin A can lead to hypervitminosis or toxicity.
These conditions are often observed as high serum calcium, high triglycerides,
or anemia in kidney patients. Kidney patients should not use supplements
with vitamin A. Many multivitamins have excessively high amounts of vitamin
A.
There are not
studies on the use of beta carotene in kidney patients, but some studies
have shown beta carotene supplementation to be potentially harmful to
individuals with normal kidney function. Until more research has been
done, kidney patients should avoid beta carotene supplements.
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Vitamin
E
Vitamin E is
important in the immune response and possibly infection rate. It is also
involved in blood clotting. Vitamin E is another vitamin which is retained
by the dialysis patient and not dialyzed off. Since vitamin E levels remain
high for dialysis patients, supplements are not necessary.
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Vitamin
D
Vitamin D is
important in bone growth and maintenance. It helps increase absorption
of ingested calcium, a necessary ingredient of bone. The active form of
vitamin D is made in the kidney. Kidney dialysis patients have low amounts
of activated vitamin D and need to be supplemented. Calcium must be given
along with vitamin D or the vitamin cannot do its job. Calcium levels
must be closely watched. If too much calcium is absorbed, the physician
often stops the vitamin D supplements. Calcium carbonate is a good supplement
for calcium and phosphorus control.
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Vitamin
K
Vitamin K is
important in blood clotting. There is no evidence that kidney dialysis
patients need vitamin K supplementation.
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B
Vitamins
The B vitamins
are B1, B2, B6, B12, biotin, pantothenic acid, niacin and folic acid.
Vitamins B1, B2, niacin, pahtothenic acid and biotin should be taken in
recommended daily amounts.
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Folic
Acid, B6 and B12
Folic acid
and vitamins B6 and B12 are very important vitamins that act together
to promote red blood cell development. Also,
they appear to control a compound known as homocysteine, which has been
identified as a possible risk factor for heart disease and stroke.
Dialysis patients have increased requirements for folic acid and vitamin
B6, needing at least 800 mcg to 1 mg or more of folic acid and 10 mg or
more of B6 each day. Vitamin B12 should be taken in recommended daily
amounts.
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Vitamin
C
Many people
believe in taking large amounts of vitamin C. That may be fine for others,
but large amounts are NOT fine for kidney patients.
Most preparations
contain at least 250 mg, and some contain up to 500 mg of vitamin C. This
is an excessive amount for the kidney patient.
The reason
why has to do with a compound called oxalate. Kidney patients already
have high levels of oxalate, and too much supplemented vitamin C increases
it. Oxalate accumulates in the blood and is not dialyzed off. Oxalate
crystals can form in bones and smooth muscle, including the heart, causing
muscle weakness and loss of function. Arthritis is another potential consequence
of oxalate accumulation.
Kidney patients
should take the recommended daily amount of vitamin C, which is 60 mg,
but no more. For kidney patients, the more vitamin C consumed, the higher
the risk of oxalate deposits in important tissues. Only Vitamins formulated
specifically for kidney patients contain the correct amount of vitamin
C, as well as the B vitamins.
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- RECOMMENDED
DAILY AMOUNTS OF VITAMINS
Here
are the proper dialysis vitamin supplements for kidney patients: |
Description |
Recommended
Daily Intake |
|
Amount |
% |
Vitamin A |
0 |
0 |
Vitamin E |
0 |
0 |
Vitamin D |
Individualized for each patient |
|
Vitamin
K |
0 |
0 |
Vitamin B1 |
1.5 mg |
100 |
Vitamin B2 |
1.7 mg |
100 |
Vitamin B6 |
10 mg |
500 |
Vitamin B12 |
6 mcg |
100 |
Folic Acid |
0.8-1.0 mg |
200-250 |
Niacin |
20 mg |
100 |
Pantothenic Acid |
10 mg |
100 |
Biotin |
0.3 mg |
100 |
Vitamin C |
60 mg |
100 |
|