B vitamins are essential for good health. However, they
are water-soluble, so are often lacking in CKD
cats, who lose much of their vitamin B through the increased urination
associated with the disease.
Cats who are not eating much will also probably not be
taking in enough B vitamins.
A lack of vitamin B may in itself cause loss of appetite, or
occasionally may cause twitching or itching. Vitamin B deficiencies are also
known to cause non-regenerative anaemia.
B vitamin supplements are safe and can often help a CKD
cat feel better.
Vitamin B12 in the form of methylcobalamin may be
particularly helpful.
The Different Types of B Vitamin
Although vitamin B is commonly referred to as if
it were a single vitamin, there are actually eight B vitamins. These
are essential vitamins, which means that they cannot be manufactured in the
cat's body, so must be obtained from external sources (i.e. from food or a
supplement). They are all water soluble, so they cannot be stored by the
body.
B Vitamin
Alternative Name
B1
Thiamine
B2
Riboflavin
B3
Niacin or niacinamide
B5
Pantothenic acid
B6
Pyridoxine or pyridoxamine
B7
Biotin, also known as vitamin H
B9
Folic acid or folate, also known as vitamin M
B12
Cyanocobalamin or methylcobalamin
PetCoach
explains more about the different B vitamins.
Nutritional management of renal disease
(2008) Sturgess K Presentation to the World Small Animal
Veterinary Association World Congress has a table showing the
recommended intake of the various B vitamins for CKD cats. Remember, this
is total intake, i.e. it includes vitamin B in food.
The Importance of B Vitamins
The B vitamins play a role in many important bodily
functions. This table shows the areas where each B vitamin plays a rôle and
possible signs of a deficiency:
B Vitamin
Alternative Name
Important For
Symptoms of Deficiency
Total Daily Requirement
B1
Thiamine
Nerve function and appetite
Neurological problems, loss of appetite
0.01 mg/lb
B2
Riboflavin
Vision and heart function
Cataracts, fatty liver
0.05 mg/lb
B3
Niacin or niacinamide
Appetite and
red blood cell production
Loss of appetite and weight loss,
bloody diarrhoea
Red blood cell production, nerve
function and appetite
Anaemia, weight loss; vomiting; diarrhoea
.00025 mg/lb
Appetite
Your cat's nutritional needs
(2006) National Research Council states
"Thiamin and niacin deficiency may contribute to anorexia associated with
renal failure."
Pharmacological appetite stimulation: rational choices
in the inappetent cat (2014) Agnew W
& Korman R Journal of Feline Medicine and Surgery16(9) pp749-56
says "Cats have a higher requirement for some B vitamins when compared
with dogs. Experimental depletion of B vitamins results in anorexia in
other species. Supplementation with B vitamins may prevent this occurring,
although no evidence exists to confirm this. Still, provision of B vitamins
is simple and should be considered in all inappetent cats."
Muscle
and Nerve Function
Some B vitamins are important for muscle and nerve
function. Deficiencies may cause twitching or itching,
and sometimes diarrhoea.
Red
Blood Cell Production
Four of the eight B vitamins play a rôle in red blood
cell production. A deficiency may cause
non-regenerative anaemia.
Your cat's nutritional needs
(2006) National Research Council states
"Human patients with CKD apparently are especially prone to pyridoxine and
folate deficiency (Gilmour et al, 1993)."
Anaemia of renal disease: what is it, what to do and
what's new (2011) Chalhoub S, Langston C & Eatroff A
Journal of Feline Medicine and Surgery13(9) pp629-40
states "Several B vitamins are necessary for erythropoiesis, including
cobalamin (B12), folic acid (B9), niacin (B3) and pyridoxine (B6).
Deficiencies of these vitamins may exacerbate anemia and increase
erythropoietin resistance."
Coat and Skin
Vitamin B deficiencies may cause itching and poor coat.
Heart
Nutritional aspects of heart disease
(2012) Di Tollo BA Veterinary Focus22(1) pp11-16
states "cats with heart disease need more B vitamins than healthy
cats. Diets for cats with heart disease should therefore contain levels of
water-soluble vitamins 2-3 times higher than that found in food for
healthy cats."
Thiamine
Deficiencies
A mild deficiency of vitamin B1 (thiamine) can cause loss
of appetite and vomiting, while a severe deficiency can cause numerous
health problems, including an inability to lift the head, blindness,
seizures and even death.
Thiamine deficiency is not common, but can arise for a
number of food-related reasons. Cats who eat fish regularly can develop
thiamine deficiency (see
Which Foods to Feed). There have
also been food recalls in the past of commercial
cat foods because they did not contain sufficient thiamine, including a recall in February 2017 of some Pets at Home dry cat foods in the UK,
as reported by the
Food Standards Agency.
There may be concerns even if foods are not recalled.
Analysis of thiamine concentrations in commercial
canned foods formulated for cats
(2014)
Markovich JE,
Freeman LM &
Heinze CRJournal of the American Veterinary Medical Association244(2)
pp175-179 examined ninety US canned cat foods and found 13.3% of
the foods contained lower thiamine levels than recommended by AAFCO.
Pâté-style foods and foods from smaller manufacturers were more likely to be
affected, though dry foods have also been implicated in the past. The study recommends that vets should consider thiamine deficiency
as a possible cause when presented with a cat with ventroflexion (an
inability to lift the head). Another common cause of ventroflexion is
low potassium
levels.
Thiamine deficiency (2006) Schaer M
NAVC Clinician's BriefAugust 2006 has a short article about
thiamine deficiency, including photos of an affected cat.
Thiamine deficiency made my cat crazy!
(2017) Steele MS VCA Animal Specialty Group discusses the case
of a cat who developed neurological problems linked to a thiamine deficiency
caused by a fish-based diet.
The Importance of B Vitamins for CKD Cats
B vitamins are particularly important for CKD cats
because these vitamins are water-soluble, so are often lacking in CKD cats
who lose much of their vitamin B through the increased urination associated
with CKD. Cats who are not eating much will also probably not be taking in
enough B vitamins. In addition, CKD cats are prone to many of the problems
caused by vitamin B deficiencies anyway, such as appetite loss or anaemia.
Your cat's nutritional needs
(2006) National Research Council
says "these patients are at risk for B-vitamin deficiency because of
decreased appetite, vomiting, diarrhea and polyuria."
Managing anemia in patients with chronic kidney
disease
(2011) Chalhoub S, Langston CE Veterinary MedicineMay 2011 says"B vitamins,
such as vitamin B12, folic acid, niacin, and vitamin B6, are important for
erythrogenesis. Supplementation is recommended in polyuric patients;
however, the contribution of vitamin supplementation to the overall
correction of anemia is minimal."
I am not sure I agree that vitamin B supplementation has a
minimal effect on anaemia. In my experience, for some CKD cats with mild
to moderate anaemia (PCV or HCT of 20-30%), this may be the only treatment
they need.
Folate
(Vitamin B9)
Folate (vitamin B9) is important for red blood cell
production (see above), but it may be of additional use to CKD patients.
Efficacy of folic acid therapy on the progression of
chronic kidney disease. The renal substudy of the China Stroke Primary
Prevention Trial (2016) Xu X, Qin
X, Li Y, Sun D, Wang J, Liang M, Wang B, Huo Y, Hou F Journal of the
American Medical Association Internal Medicine176(10)
pp1443-1450 found that giving folic acid together with an ACE inhibitor
(enalapril) to human CKD patients with hypertension in China "can
significantly delay the progression of CKD among patients with
mild-to-moderate CKD."
Niacin
(Vitamin B3)
Niacin ameliorates oxidative stress, inflammation,
proteinuria, and hypertension in rats with chronic renal failure
(2009) Cho K, Kim H, Rodriguez-Iturbe B & Vaziri ND
American Journal of Physiology - Renal Physiology297 ppF106–F113 looked at the use of niacin in rats with artificially induced
kidney disease (5/6ths of their kidneys were surgically removed). The
study found that rats given 50mg/kg of niacin in their drinking water for
twelve weeks appeared to do better than rats not given niacin. The study
concludes "niacin supplementation helps to attenuate histological injury
and mitigate upregulation of oxidative and inflammatory systems in the
remnant kidney."
One human study,
A randomized double-blind placebo-controlled trial
of niacinamide for reduction of phosphorus in hemodialysis patients
(2008) Cheng SC, Young DO, Huang Y, Delmez JA & Coyne DW
Clinical Journal of the American Society for Nephrology3(4)
pp1131–1138, found that vitamin B3 (niacin) helped reduce phosphorus
levels. The patients in the study did continue to receive standard
phosphorus binders during the trial as well, but later trials used vitamin
B3 alone to control phosphorus levels. See
Phosphorus Binders for more
information on this.
Which B Vitamins to Give
Your vet will often routinely offer vitamin B supplementation
for your cat. If not, I would raise the subject yourself. This is particularly important if your
cat is anaemic or at the low end of the
laboratory range for PCV or HCT
(measures of anaemia), but even non-anaemic cats often seem to feel and act
better when given additional B vitamins, exhibiting improved appetite and
increased energy levels.
Many people with CKD cats give their cat two main forms
of vitamin
B supplement:
vitamin B complex; plus a
separate vitamin B12 supplement
Vitamin B Complex
Although you can buy the eight B vitamins individually,
it can be fiddly and more expensive to work out the correct dose for a cat.
You need to be careful not to over-supplement B6 and B9 in particular.
Therefore most people use vitamin B complex for their
CKD cats, as described below.
Vitamin B12
Vitamin B12 can be particularly useful for CKD cats, but there is only a relatively
small amount of vitamin B12 in most B complex supplements, so some people
give a separate B12 supplement as well. This is especially important for
anaemic cats. There is more about vitamin B12
below.
Vitamin B Complex
B vitamins need
to be in a certain ratio to each other, so many people buy their
supplements in the form of a vitamin B complex. These are usually human products
and they are supposed to
contain the correct balance of B vitamins, though obviously if you are using
a human
product, you will need to reduce the dose so it is suitable for a cat..
B vitamins are sensitive to heat and light so
are best kept in a cool dark place.
B vitamins may make urine yellow or orange,
so don't panic if you see this.
There are a number of recommendations for total daily vitamin B intake for
cats, and they can vary quite a lot. Here are the recommendations from the
National Research Council for B vitamins for a healthy cat compared with
the recommendations for a CKD cat from Dr K Sturgess:
You will note some of the measurements are in mg and some are in μg, be
careful not to get these confused because they are very different.
mg = milligram
μg = microgram
A microgram is 1000 of a
milligram i.e. 1000 μg = 1 mg
Vitamin B Complex Formulations
There are three
main ways to give vitamin B complex:
orally
injected into
the cat
injected into the subcutaneous fluid bag
There are a wide range of vitamin B complex products available throughout
the world. The vast majority are made for humans but these are commonly used
for cats in reduced, cat-sized doses. Here are some products which are
widely used on Tanya's CKD Support Group, but check with your vet before
using.
Here are the most popular brands on Tanya's CKD
Support Group. Be sure to check with your vet before you use any of these
products, because
your vet may wish you to give less of certain B vitamins. If so, you
should of course comply.
Oral Vitamin B Complex:
Human Products
B vitamin supplements are widely available for human use, and therefore need to be
divided into cat-sized doses. The general
rule of thumb is to give a 10 lb cat approximately 1/10th of a human dose
each day. Thus, if you buy a product where the dose for a human is one
capsule a day, one capsule would be enough to last a cat for ten days.
Ideally, you
then want to divide this daily dose further into 2-3 doses each day if you
can, but in practice that is not easy, since you are talking tiny amounts.
If you buy
tablets, you can crush them and divide them (usually into ten) after crushing. If you use
capsules, you can open the capsule and divide its contents. Either way, it
can be fiddly obtaining cat-sized doses, but there are tips
below.
Jarrow's
B-Right
Jarrow
Formulas
B-Right is a popular choice because it contains all
the B vitamins including B9 (folic acid), and some B12 in the favoured
methylcobalamin form.
It is also widely available.
The formulation changes at intervals, but the current formulation (August
2020) appears to be acceptable and is used by many people on Tanya's CKD
Support Group with no problems.
Jarrow's B-Right: Sources
Jarrow's B-Right is widely available.
USA
Vitacost sells 100 capsules of Jarrows
B-Right for US$13.74. Shipping is a flat rate US$4.99 per order.
iHerb sells
100 capsules of Jarrows B-Right for US$15.02 plus shipping (US$4 to NYC).
Amazon sells 100 capsules but they are currently (August
2020) not available.
UK
Amazon UK sells 100 Jarrows B-Right
capsules for £16.95.
Australia
Megavitamins sells Jarrows B-Right in
Australia for AUD$36.50 plus shipping.
Swanson Ultra Activated B-Complex High
Bioavailability
This product contains all eight B vitamins, but it also contains
inisotol (previously known as vitamin B8) and PABA (previously known as
vitamin B10).
WonderLabs
explains how they are no longer referred to as B vitamins because they
no longer fit the definition of a vitamin.
Swanson sells the product in the UK. It
is available from a UK distributor, though this is currently out of stock;
however, you can have it shipped from the USA.
Dividing Human-Sized Vitamin B Complex
Capsules Into
Cat-sized Doses
I have been
asked so often about how to divide the small amount in these capsules into
ten. There are a number of ways people on Tanya's CKD Support Group do
this:
Empty the contents of the capsule onto foil and divide it roughly into ten
with a knife or razor.
Pour the capsule contents into a shallow bowl or plate and divide it
into ten.
Use
measuring spoons. These are discussed
here. These spoons can vary a bit in size depending upon the
manufacturer but apparently the drop spoon holds about a tenth of a Jarrows
B-Right capsule and the smidgen spoon holds about an eighth of a Jarrows
B-Right capsule. The easiest way to determine which size spoon to use is
to divide the capsule contents into ten, then tip a tenth into the spoon
you think might work; however, once you've decided which size spoon to
use, you can just scoop up enough of the powder to fill the spoon.
Ideally, you
then want to divide the daily dose further into 2-3 doses each day if you
can, but in practice that is not easy, since you are talking tiny amounts.
Therefore once the
original capsule contents have been divided into ten cat-sized doses, most people find
the simplest thing is to decant the portions into ten
empty
gelatin capsules and give a capsule once daily. People dividing
their dosage on pieces of foil may carefully tear the foil and fold it
into a funnel shape, which they then use to pour the powder into an empty
gelcap. Other people prefer to buy a little funnel specially for this
task. Members have used this
Torpac
one, or have found
them in the USA at Bed, Bath and Beyond for about US$2.
One person
actually found that if she emptied out the contents of a Jarrows B-Right
capsule, the correct cat-sized dosage (one tenth of the original capsule) filled one half of a size 5 gelcap
to the top, so she simply used the empty size 5 gelcap to scoop up the
powder. She could then pop other medications in the capsule as well if
necessary, by squashing down the powder with the additional medications.
Oral Vitamin B Complex:
Veterinary
Products
Thorne B-ComplexVet
ThorneVet B-ComplexVetis a veterinary product which
contains B vitamins including methylcobalamin. It is available as a soft
chew, though I don't know if cats would be happy to eat it as is or not.
It also contains some rather odd ingredients, including rosemary extract,
coconut oil and white vinegar. Personally, I think I'd stick to the human
products discussed above.
Oral Vitamin B Complex Dosages for
Commonly Used
Products
Here are tables showing the composition of the above mentioned products and
how much of each B vitamin you would be giving if you gave the usual
cat-sized dosages:
Recommended Total
Daily Intake Including From Food for a
9 lb (4 kg)
CKD Cat
Human Products
Veterinary Products
Jarrows
B-Right
Swanson Ultra Activated High
Bioavailability
Thorne B ComplexVet
B Vitamin
One capsule contains:
One capsule contains:
One capsule contains:
B1 Thiamine
0.32 - 1.0 mg
25 mg
36 mg
110 mg
B2 Riboflavin
0.36 - 1.28 mg
25 mg
25 mg
18.2 mg
B3 Niacin
3.6 - 7.2 mg
25mg
50 mg
140 mg
B5 Pantothenic Acid
0.3 - 0.72 mg
125 mg
25 mg
120 mg
B6 Pyridoxine
0.28 - 0.8 mg
35 mg
25 mg
15.8 mg
B7 Biotin
6.0 - 12.0 μg
300 mcg
25 mcg
400 mcg
B9 Folic Acid
64 -160 μg
400 mcg
400 mcg
400 mcg
B12 Cobalamin
1.2 - 4.0 μg
100 mcg
250 mcg
400 mcg
Commonly used dosage for cats:
One tenth of
a capsule
per day
One tenth of a capsule
per day
One quarter of a
soft chew per day
If you give the
usual cat-sized doses of these products, you would be giving:
Recommended Total
Daily Intake Including From Food for a
9 lb (4 kg)
CKD Cat
Human Products
Veterinary Products
B Vitamin
Jarrows
B-Right
Swanson Ultra Activated High Bioavailability
Thorne B ComplexVet
Commonly used dosage for cats:
One tenth of
a capsule
per day
One tenth of
a capsule
per day
One quarter
of a capsule
per day
B1 Thiamine
0.32 - 1.0 mg
2.5 mg
3.6 mg
27.5 mg
B2 Riboflavin
0.36 - 1.28 mg
2.5 mg
2.5 mg
4.55 mg
B3 Niacin
3.6 - 7.2 mg
2.5 mg
5.0 mg
35 mg
B5 Pantothenic Acid
0.3 - 0.72 mg
12.5 mg
2.5 mg
30 mg
B6 Pyridoxine
0.28 - 0.8 mg
3.5 mg
2.5 mg
3.95 mg
B7 Biotin
6.0 - 12.0 μg
30 mcg
2.55 mcg
100 mcg
B9 Folic Acid
64 -160 μg
40 mcg
40 mcg
100 mcg
B12 Cobalamin
1.2 - 4.0 μg
10 mcg
25 mcg
100 mcg
As you can see, there are quite a few differences between the various
formulations. Be guided by your vet as to the best approach for your cat.
Injectable Vitamin B Complex
I think every vet on the planet has this available. My vet often gives my
cats a one-off shot if they are off colour, but for CKD cats who are not
visiting the vet every week or so, it can be easier to give the shots at
home.
In
jectable B complex (which is yellow)
does sting when injected though, so oral dosing may be better; but it might
be worth using the injectable form in vomiting cats.
Some vets add vitamin B complex to the sub-Q
fluids bag, but this is not a good idea because it can make the fluids
sting; it can compromise the sterility of the bag; and giving vitamins in
this way (i.e. added by the vet) tends to increase the cost of the fluid
bags. In addition, since most people warm their fluids before using them,
the B vitamins could well be rendered ineffective through the repeated
warming.
Vedco 1000mcg strength
is used by some members of Tanya's CKD Support Group in the USA. It requires a
prescription.
Injectable Vitamin B Complex
Dosages
For humans, the
recommended dosage of the Vedco product is 1-5ml per 100 lbs of bodyweight
given once or twice a week.
For a 10 lb (4.5kg) cat, the equivalent dose would be 0.1 - 1.0 ml once or
twice a week, but the Vedco link says "Dogs and Cats 0.25 to 0.5 mL May be
repeated once or twice a week, as indicated by the condition and response
of the animal." Be guided by your vet.
The Vedco
product contains a relatively high amount of vitamin B1 (thiamine) and
Vedco does mention "Parenteral administration of thiamine has resulted in
anaphylactic shock. Administer slowly and with caution doses over 1/3 mL
(50 mg thiamine)."
Injectable Vitamin B
Complex Sources
USA
Thriving Pets sell a 100ml bottle of
injectable vitamin B complex for $9.95. If you enter
the word "tanya" (without the ") in the promotional code box, you will
receive a 10% discount on orders over US$100. Shipping is free for orders
over US$49 after the discount.
UK and Other
Countries
I do not know
of any stockists but your vet probably can assist.
Avoid products containing alpha lipoic acid, because it is toxic to
cats.
Increased vocalisation in elderly cats
(2015) Gunn-Moore DA European Journal of Companion Animal Practice 25(3) pp20-29 states "Unfortunately,
alpha-lipoic acid is toxic in cats so products containing it should not be
given."
NutriVed is something I used to recommend but I discovered it
now apparently contains propylene glycol, which is safe for dogs but not
allowed in cat foods because it can cause red blood cell abnormalities,
not exactly what you want in an anaemic cat.
Propylene glycol: educate yourself and your
veterinary clients (2015)
Scheidegger S DVM360 Magazine explains more about propylene glycol.
Hi-Vites and
Felovite II are US multivitamin products. There is nothing
wrong with these products as such, but unfortunately they tend to be too high in
vitamin A and
D for a
CKD cat, and Felovite II also contains
phosphorus.
Several cats on the support group
have not done well on Hi-Vites in particular.
Aventi KP Kidney Support (formerly Renal Advanced)
is a product made by Candioli which is commonly offered to people
in Italy and Canada.
Drugs
has some information about it. It contains vitamin B6, vitamin B12 and vitamin B9
(folic acid), plus
probiotics. However, it also contains prebiotics in the form of
fructooligosaccharides (FOS) which may increase
calcium levels in some cases. Personally I would just use B vitamins, and
give a probiotic separately if appropriate.
Renal Essentials
is another product which contains a few B vitamins together with
other ingredients including additional
potassium. Not all CKD cats need
added potassium, but if yours does, there is probably not enough potassium
in this product to make a difference. Again, I would just use B vitamins,
and give potassium separately if appropriate.
B Vitamins with Iron: Pet-tinic (Pet-Tabs Iron-Plus)
Some cats (typically anaemic
ones) may need iron as well as B vitamins. In these cases it is usually
easier to use a combined product, but you should never give iron to a cat
with an infection. Most people on Tanya's CKD Support Group use Pet-tinic.
The dosage recommended by the manufacturer for a 10lb
(4.5kg) cat is 1 ml twice a day.
Vitamin B
One teaspoon (5ml) contains
Recommended Dose Twice a Day
Total Daily Dose
B1 thiamine
2.0 mg
0.4 mg
0.8 mg
B2 riboflavin
1.0 mg
0.2 mg
0.4 mg
B3 niacin
10.0
mg
2.0 mg
4.0 mg
B6 pyridoxine
1.0 mg
0.2 mg
0.4 mg
B12 cyanocobalamin
2.1
mcg
0.21
mcg
0.42
mcg
Iron
12.5
mg
2.5mg
5.0 mg
You can read more about it, including where to purchase it,
here.
Vitamin B with Potassium (Kaminox or Renal
K+)
Products with Potassium: Renal K+, Amino B & K and Kaminox
These products contain both B vitamins and
potassium gluconate, though whether the amounts of vitamin B are enough to be of
any real benefit is debatable, and not every CKD cat needs additional
potassium. Some of them also contain iron, which may be necessary for
anaemic cats, but which should never be given to a cat with an infection.
Personally I would use separate potassium and
B vitamins products as appropriate, which should also work out cheaper.
See
Potassium for more information on these products.
Vitamin B12 - Cobalamin (Methylcobalamin and Cyanocobalamin)
Vitamin B12, or cobalamin, is important for nerve cells,
energy production and red blood cell production. A lack of vitamin B12 may contribute to a variety of problems,
including
cognitive dysfunction.
Although vitamin B12 is often included in vitamin B
complex formulations, there is usually too little vitamin B12 for it to be
of much use. Therefore
many people with CKD cats give both a vitamin B complex and a separate
vitamin B12 product.
Plasma homocysteine, B vitamins, and amino acid
concentrations in cats with cardiomyopathy and arterial thromboembolism
(2000) McMichael MA, Freeman LM, Selhub J, Rozanski EA, Brown DJ,
Nadeau MR, Rush JE Journal of Veterinary Internal Medicine14(5)
pp507-12 found that cats with
heart disease who
have
arterial thromboembolism (saddle thrombus) have significantly
lower levels of vitamin B6, vitamin B12 and arginine, an amino acid. The
study concludes "We interpret the results of this study to suggest that
vitamin B12 and arginine may play a role in CM and ATE of cats." If your cat
has heart disease, therefore, you may wish to discuss using methylcobalamin
with your vet.
Journal of Feline Medicine and Surgery20(2) pp135-141
measured cobalamin and folate levels in cats of differing ages and concludes
"this finding suggests that older cats, independent of diet, are at an
increased risk of cobalamin deficiency."
Vitamin B12 may be particularly useful for CKD cats. According to
Renal and Urology News,
B12 supplements help reduce inflammation in CKD.
Chronic renal failure promotes severe variant of
Vitamin B12 deficiency (2006) Duning
T, Nabavi DG, Dziewas R, Kugel H & Schäbitz W-R European Neurology
56 pp62–65 reports on the case of a human CKD patient with vitamin B12
deficiency and concludes that CKD patients "may
require earlier and much larger therapeutic cobalamin doses than previously
considered."
Many CKD cats have
anaemia. Vitamin B12 is
essential for red blood cell production, so too low a level of vitamin B12
in your cat's body may cause or
contribute to anaemia, therefore vitamin B12 supplements may help treat
anaemia.
Treatment of confirmed B12 deficiency in hemodialysis
patients improves Epogen requirements
(2013) Saifan C, Samarneh M, Shtaynberg N, Nasr R, El-Charabaty E &
El-Sayegh S International Journal of Nephrology and Renovascular Disease6 pp9–93 found that giving vitamin B12 supplements to human CKD
patients with low levels of vitamin B12 led to a reduced need for
ESAs to treat CKD-related
anaemia.
Medicines used to control gastric hyperacidity such as
famotidine
(Pepcid AC),
ranitidine (Zantac 75) or
omeprazole (Prilosec) may reduce the
absorption of vitamin B12 from food.
Proton pump inhibitor and histamine H2 receptor
antagonist use and vitamin B12 deficiency
(2013) Lam JR, Schneider JL, Zhao W
& Corley DA Journal of the American Medical Association 310(22)
pp2435-2442 found that in humans "gastric acid inhibitor use was
significantly associated with the presence of vitamin B12 deficiency."
Oregon State University
states "Proton-pump inhibitors (e.g., omeprazole and
lansoprazole)...markedly decrease stomach acid secretion required for the
release of vitamin B12 from food but not from supplements." Therefore
if you are using acid blockers, your cat might benefit from a vitamin B12
supplement.
Vitamin B12: Methylcobalamin
versus Cyanocobalamin
There are two forms of cobalamin (vitamin B12),
cyanocobalamin and methylcobalamin, but cyanocobalamin tends to be routinely
offered rather than methylcobalamin.
Methylcobalamin is the neurologically active form of
vitamin B12, and is used by the body to correct or prevent neurological
problems. Cyanocobalamin is an artificial form of vitamin B12,
which has to be converted into methylcobalamin before the body can use it.
In the process, a tiny amount of cyanide is
produced. This amount of cyanide is so small that it is considered to be harmless, but a
human study,
B vitamin therapy for homocysteine: renal function and
vitamin B12 determine cardiovascular outcomes
(2013) Spence JD Clinical Chemistry and Laboratory Medicine
51(3) pp633-7, found that "high-dose cyanocobalamin leads
to accumulation of cyanide in patients with renal failure. B vitamin therapy
is beneficial in patients with good renal function, but harmful in patients
with significantly impaired renal function (a glomerular filtration rate
<50). It seems likely that in patients with renal impairment,
methylcobalamin should be used instead cyanocobalamin."
Since methylcobalamin is more bioavailable, and therefore
more effective because it is absorbed more readily by the body, I would
recommend giving it to your cat in the first place if possible. However,
some members of Tanya's CKD Support Group do use the injectable form of cyanocobalamin, which is much more
widely available than injectable methylcobalamin.
Vitamin B12 Formulations: Oral or
Injectable
Vitamin B12 is available in oral or injectable
forms, but the injectable form is almost always cyanocobalamin rather than methylcobalamin (I do know of one US compounding pharmacy which
provides injectable methylcobalamin, see
below).
It used to be thought that only the injectable form of
vitamin B12
was effective, and indeed this may well be the case for cats with
gastrointestinal disease, who may have problems absorbing oral medications.
The Gastrointestinal Laboratory at Texas A&M
University says "Until similar studies evaluating the efficacy of
oral cobalamin supplementation in dogs and cats have been published, the
parenteral route continues to be the route of choice." However, in a
later article,
Treatment of cobalamin deficiency in dogs and cats
(2016) Clinician's Brief, Dr J Steiner, head of the Gastrointestinal
Laboratory, says "Supplementation has traditionally been administered
parenterally because cobalamin deficiency has been shown to lead to
malabsorption of cobalamin in the ileum; however, recent data have shown
that oral supplementation may be just as efficacious."
For patients without gastrointestinal disease, the oral route is
definitely an option.
Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency
(2005) Vidal-Alaball J, Butler CC, Cannings-John R, Goringe A, Hood
K, McCaddon A, McDowell I & Papaioannou A Cochrane Database of Systematic
Reviews 20(3) found that oral vitamin B12 was as effective as
intramuscular vitamin B12 for human patients with vitamin B12 deficiency.
Efficacy of oral cobalamin (vitamin B12) therapy
(2010) Andrès E, Fothergill H & Mecili M Expert Opinion on
Pharmacotherapy11(2) pp249-56 examined a number of studies and
says these "provide evidence that oral cobalamin treatment may adequately
treat cobalamin deficiency. The efficacy was particularly highlighted when
looking at the marked improvement in serum vitamin B12 levels and
hematological parameters, for example hemoglobin level, mean erythrocyte
cell volume and reticulocyte count. The effect of oral cobalamin treatment
in patients presenting with severe neurological manifestations has not yet
been adequately documented." The study concludes "Our experience and the
present analysis support the use of oral cobalamin therapy in clinical
practice."
Many members of Tanya's CKD Support Group have
successfully used orally administered methylcobalamin for their CKD cats.
Some people whose cats have severe anaemia hedge their bets by using the
injectable form as discussed below and giving the oral form on the other
days; however, severe anaemia may well require other treatments in addition
to methylcobalamin. Discuss the best approach for your cat with your vet.
Vitamin B12 Oral
The oral form of methylcobalamin does seem to work well
for CKD cats, though it may be less effective in cats with IBD
(inflammatory bowel disease) or
pancreatitis. It is common to give a
relatively high dose though, to make sure the cat receives enough (any
excess should be passed out in the urine).
Oral methylcobalamin is often sold in the form of
fruit-flavoured lozenges which some people do use to pill their cats
successfully, though plain methylcobalamin tablets and capsules are also available
and what I would choose. See
below for stockists.
Some methylcobalamin products contain a sweetener called
xylitol. Although this is toxic to dogs, there is currently no evidence that
it is toxic to cats, according to.
Effects of p.o. administered xylitol in cats
(2018) Jerzsele A, Karancsi Z, Pászti‐Gere E, Sterczer A, Bersényi A, Fodor
K, Szabó D & Vajdovich P Journal of Veterinary Pharmacology and Therapeutics41(3) pp409-414.
However, some people prefer to avoid products
containing it.
Vitamin B12 Oral Dosages
A possible starting dose for oral
methylcobalamin would be 500mcg (0.5mg) a day, though some people give twice
as much. Although this sounds high, only a small percentage of oral B12 is
absorbed.
The Gastrointestinal Laboratory at Texas A&M
University says "Since cobalamin is a water-soluble vitamin,
excess cobalamin is excreted through the kidneys and clinical disease due to
over-supplementation has not been described."
Most people using capsules simply open a 500mcg capsule
and mix the contents with their cat's food. Ideally, I would divide this
daily dose between two meals a day, i.e. give 250mcg with breakfast and
250mcg with dinner.
You may be offered
Cobalequin,
which is made by the manufacturer of Cosequin (used for
arthritis).
Cobalequin is marketed for dogs and is supplied in packs of 45 chewable
tablets which are chicken flavoured. They contain 250mcg of cobalamin and a
form of folic acid known as 5-MTHF, however, the cobalamin is in the form of
cyanocobalamin, so there are probably better choices available.
Some national chains sell methylcobalamin, but it is
often in lozenge form rather than capsules. Check for other ingredients too.
Sells
300 plain methylcobalamin 500mcg (0.5mg) capsules for US$10.68 plus flat
rate shipping of US$4.99 per order. I ordered
these myself on a Sunday evening, and received them on the following
Tuesday. If you are a new Vitacost customer, you can use this
coupon
to get a US$10 discount off your first order.
Makes 1000mcg methylcobalamin lozenges. They are available from
Vitamin Shoppe for US$13.69 or
Amazon (currently unavailable), and you can often find
this product in stores too. This product contains lactose, so may not be
suitable if your cat is lactose intolerant.
Makes 1000mcg
methylcobalamin chewable tablets. They are often available from
Amazon (currently unavailable). One member of Tanya's Support
Group cuts these into quarters, dissolves the quarter in water, then adds it
to food.
This product also contains lactose, so may not be suitable if your cat is
lactose intolerant.
Vitamin B12 Oral Sources - UK
You may be offered
Cobalaplex, which contains vitamin B12 and
vitamin B9 (folic acid), but this contains
cyanocobalamin rather than methylcobalamin. It also contains
fructooligosaccharides (FOS), which may bind calcium in the small intestine
and lead to an increase in calcium levels in the body (hypercalcaemia),
which is not good for cats who already have high calcium levels.
You may also be offered
Cobalequin,
which is made by the manufacturer of Cosequin (used for
arthritis).
Cobalequin is marketed for dogs and is supplied in packs of 45 chewable tablets
which are chicken flavoured. They contain 250mcg of cobalamin and a form of
folic acid known as 5-MTHF, however, the cobalamin is in the form of
cyanocobalamin, so there are probably better choices available.
Some health food shops sell the Solgar brand of methylcobalamin, but it is
often not easy to find methylcobalamin in UK stores, so you will probably
have to shop online.
Makes 1000mcg methylcobalamin lozenges. They are available from
Health Monthly or
Amazon UK. The Superior Source
product contains
lactose, so may not be suitable if your cat is lactose intolerant.
Sells
300 plain methylcobalamin 500mcg (0.5mg) capsules for US$10.68
plus international shipping, which is calculated by weight but which costs
roughly USD6.99 for small, lightweight orders and takes 7-14 days. Vitacost have local phone numbers in
UK, Australia and Hong Kong. I have not used Vitacost to ship to the UK, but
I used them within the USA and they were very efficient and very fast.
If you are a new Vitacost customer but know somebody who
already uses them, you should be able to use this
coupon to get a US$10 discount off your first order.
Sells 90 1000mcg methylcobalamin tablets by
Natural Factors for CAN$8.66. These
contain lactose, so may not be suitable if your cat is lactose intolerant.
Sells
300 plain methylcobalamin 500mcg (0.5mg) capsules for US$10.68
plus international shipping, which is calculated by weight but which costs
roughly USD6.99 for small, lightweight orders and takes 7-14 days. Vitacost have local phone numbers in
UK, Australia and Hong Kong. I have not used Vitacost to ship to the UK, but
I used them within the USA and they were very efficient and very fast.
Unfortunately they will not ship to Canada.
Has details of suppliers in USA, UK, and New Zealand, some of
whom will ship worldwide. Please note this site is recommending
methylcobalamin for cats with diabetes, so the sizes and doses may be too high for a CKD cat; ask your vet.
Vitamin B12 Injectable
Injectable vitamin B12 is only available via
prescription in the USA, but is an over the counter product in
Canada. See
below for stockists, including a US supplier of injectable methylcobalamin.
Unlike vitamin B complex, injectable vitamin
B12 (which is a pinky red colour) does not sting, so some people give this
to their cats during or immediately after sub-Qs.
The US National Library of Medicine
mentions that many injectable forms of vitamin B12 in the form of
cyanocobalamin "contain aluminum that may be toxic. Aluminum may reach
toxic levels with prolonged parenteral administration if kidney function is
impaired." If you are only using the injectable form
occasionally, it is probably safe but discuss this further with your vet.
Injectable methylcobalamin apparently does not contain aluminium (the
version I know of is preserved with methyl alcohol).
Doses are lower than for oral administration because less
is wasted when the injectable form is used.
A commonly used dose for injectable cyanocobalamin is
250-500mcg every week or every two weeks.
Drugs
recommends 0.25 to 0.5 ml of the 1000mcg/1ml concentration (so 250-500mcg),
every 1-2 weeks as required
Although it is more bioavailable than cyanocobalamin, I
understand from those who have used injectable methylcobalamin that the
dosage is the same as for injectable cyanocobalamin, i.e. 0.25ml of the
1000mcg/ml strength (which is 250mcg); however, it is normally only given every 2-4 weeks
(although some
members of Tanya's Support Group give it more often). Be guided by your
vet on the best protocol for your cat.
Vitamin B12 Injectable Sources
A prescription is required. These products are normally only usable for
twenty eight days after opening.
apparently sells injectable methylcobalamin. It is not mentioned on their site but members of my
support group have obtained it from them with no problems. It used to cost US$39.95
for a 5ml vial of 1000 mcg/ml (1 mg/ml) strength plus US$10 shipping, with a three
month expiration date. They also sell cyanocobalamin if required.
sell 1000 mcg/ml (1 mg/ml) injectable methylcobalamin, apparently in a 30ml
vial, which means some will probably be wasted. It costs around US$30 plus
shipping of around US$12-15.
Sells a 250ml bottle of
injectable cyanocobalamin 1000mcg/ml strength for US$7.09 or 250ml for
US$15.55.
You can usually obtain injectable cyanocobalamin from your local Costco
pharmacy. You can also search
Good RX for cyanocobalamin.
Vitamin B12
Injectable Sources: UK
Injectable cyanocobalamin used to be licensed for animals
in the UK. One popular brand was Anivit. Unfortunately
this seems to have been discontinued. The
NHS seems to favour hydroxocobalamin for humans because it stays in the body
for longer, and I have heard of people also using this in their cats.
sell a vial containing 20mg of methylcobalamin for £25
plus VAT and shipping. You add 10ml of sterile saline to the vial, giving
you a strength of 2mg per 1 ml. I am informed the reconstituted
product will then last for around 18 months, which seems a long time to me. I do not know anybody who has used this as yet.
Vitamin B12 Injectable Sources:
Canada
Most pharmacies in Canada carry injectable cyanocobalamin
and no prescription is required. It only costs around CAN$7.
Has details of suppliers in USA, UK, and New Zealand, some of
whom will ship worldwide. Please note this site is recommending
methylcobalamin for cats with diabetes, so the sizes and doses may be too high for a CKD cat; ask your vet.
Vitamin B12 Cautions
Side Effects
Drugs mentions that side effects of
vitamin B12 supplementation may include itching and diarrhoea. If you see these signs,
speak to your vet about reducing the dose.
Vitamin B12 and Potassium
Vitamin B-12 associated neurological diseases workup
(2016) Singh NN Medscape states that when patients with a
vitamin B12 deficiency and severe anaemia are given vitamin B12,
"Hypokalemia [low potassium levels] may develop because of increased
potassium utilization in hematopoiesis."
Most CKD cats do not have a cobalamin deficiency as such, and
How I treat cobalamin (vitamin B12) deficiency
(2008) Carmel R Blood 112(6) pp2214-2221 says that such
falls in potassium levels are usually transient and "its clinical relevance
has never been proven." If your cat already has severe anaemia and low
potassium levels, speak to your vet before starting methylcobalamin.
Vitamin B12 and Cancer
Hypercobalaminaemia is associated with hepatic and
neoplastic disease in cats: a cross sectional study
(2014) Trehy MR, German AJ,
Silvestrini P, Serrano G & Batchelor DJ BMC Veterinary Research10 pp175 looked at elevated cobalamin levels in cats who had not
received vitamin B supplementation and states "The current study has
suggested possible associations between hypercobalaminaemia and the presence
of either solid neoplasia or liver disease in cats."
Purina Pro Club Update (2013) 12(1)
Dr Sysel of the Bauer Research Foundation states "Vitamin B12 is important
in DNA synthesis, as cells cannot divide without it. Rapidly growing tumors
that are actively dividing have an especially high demand for vitamin B12.
Tumor cells produce TCII [transcobalamin, a protein which moves vitamin B12
through the bloodstream] to obtain all the vitamin B12 they can."
University of Pennsylvania School of Veterinary
Medicine has been researching whether cats with
lymphoma
might actually have a vitamin B12 deficiency
(which is quite possible, because lymphoma may reduce vitamin B12 absorption
in the intestines), and if they do, they plan to offer supplemental
treatment to address the deficiency.
Vitamin B12 and Diabetes
Cats with diabetes tend to be given relatively high dosages
of methylcobalamin.
However,
Effect of
B-vitamin therapy on progression of diabetic nephropathy: a randomized
controlled trial (2010) House AA, Eliasziw M, Cattran DC, Churchill DN,
Oliver MJ, Fine A, Dresser GK & Spence JD Journal of the American Medical
Association303(16) pp1603-1609 found that humans with diabetes
and kidney disease caused by the diabetes who were given three B vitamins (25mg/d of vitamin B6 (pyridoxine), 2.5mg/d of vitamin B9 (folic acid) and
1mg/d of vitamin B12) had a lower
GFR (a measure of kidney function) and an
increased incidence of strokes. The study states "Because these vitamins are
water-soluble and renally excreted, vitamin toxicity may be more of a
concern in patients with impaired renal function."
Cats with diabetes are usually only given methylcobalamin for up to three
months, until the diabetes is regulated, but the humans in this study were
taking cobalamin for 36 months. It is also not known which form they were
taking, but most probably it was cyanocobalamin. These patients had severe
diabetes as well as advanced CKD and were receiving multiple treatments
apart from B vitamins.
I would not give more than 1 mg a day to your CKD cat, and personally, I
would feel more comfortable giving 500mcg (0.5mg) only. Be guided by your
vet as to the most appropriate dose for your cat.
TREATING YOUR CAT WITHOUT VETERINARY ADVICE CAN BE
EXTREMELY DANGEROUS.
I have
tried very hard to ensure that the information provided in this website is
accurate, but I am NOT a vet, just an ordinary person who has lived
through CKD with three cats. This website is for educational purposes
only, and is not intended to be used to diagnose or treat any cat. Before
trying any of the treatments described herein, you MUST consult a
qualified veterinarian and obtain professional advice on the correct
regimen for your cat and his or her particular requirements; and you
should only use any treatments described here with the full knowledge and
approval of your vet. No responsibility can be accepted.
If your cat
appears to be in pain or distress, do not waste time on the internet,
contact your vet immediately.
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This site is a labour of love, from which I do not make
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If you wish to
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