B12 insufficiency/MS
Re: B12 insufficiency/MS
When laughing gas isn't funny... demyelination due to inactivation of B12.
A case of unusual substance abuse causing myeloneuropathy.
Spinal Cord. 2007 Apr;45(4):314-7.
STUDY DESIGN: Case report.
OBJECTIVES: Examine an unusual drug related case of myeloneuropathy as well as the pathophysiology of nitrous oxide induced subacute combined degeneration.
SETTING: Major metropolitan teaching hospital - Princess Alexandra Hospital, Queensland, Australia.
METHODS: Review case notes, investigations, relevant medical literature and epidemiological data.
RESULTS: A 23-year-old female developed a myeloneuropathy and encephalopathy after an 8-month history of nitrous oxide abuse. Her presentation was complicated by acute renal failure, deep vein thrombosis (DVT) and pulmonary embolism (PE) as well as severe cognitive deficits. After eight months of multidisciplinary rehabilitation the patient is able to walk short distances with mobility aids and is able to manage self cares. However, she still requires a wheelchair for long distances and will have significant residual neurological deficits.
CONCLUSION: The abuse of nitrous oxide has potentially serious outcomes that require discussion of issues related to harm minimisation and health promotion.
A case of unusual substance abuse causing myeloneuropathy.
Spinal Cord. 2007 Apr;45(4):314-7.
STUDY DESIGN: Case report.
OBJECTIVES: Examine an unusual drug related case of myeloneuropathy as well as the pathophysiology of nitrous oxide induced subacute combined degeneration.
SETTING: Major metropolitan teaching hospital - Princess Alexandra Hospital, Queensland, Australia.
METHODS: Review case notes, investigations, relevant medical literature and epidemiological data.
RESULTS: A 23-year-old female developed a myeloneuropathy and encephalopathy after an 8-month history of nitrous oxide abuse. Her presentation was complicated by acute renal failure, deep vein thrombosis (DVT) and pulmonary embolism (PE) as well as severe cognitive deficits. After eight months of multidisciplinary rehabilitation the patient is able to walk short distances with mobility aids and is able to manage self cares. However, she still requires a wheelchair for long distances and will have significant residual neurological deficits.
CONCLUSION: The abuse of nitrous oxide has potentially serious outcomes that require discussion of issues related to harm minimisation and health promotion.
Re: B12 insufficiency/MS
Hi,
After reading this topic, I decided to try sublingual B12 (Methylcobalamine) on a daily basis.
Can you pls provide some help here?
Sublingual Methylcobalamin (Vitamin B12), 1000 mcg, 60 Nuggets are on the way
1- Is it ok if I take one nugget per day at breakfast time?
2-Should I take it everyday for some time, and then space it a bit?
Thks very much for the help
After reading this topic, I decided to try sublingual B12 (Methylcobalamine) on a daily basis.
Can you pls provide some help here?
Sublingual Methylcobalamin (Vitamin B12), 1000 mcg, 60 Nuggets are on the way
1- Is it ok if I take one nugget per day at breakfast time?
2-Should I take it everyday for some time, and then space it a bit?
Thks very much for the help
Re: B12 insufficiency/MS
Sure.zen2010 wrote:After reading this topic, I decided to try sublingual B12 (Methylcobalamine) on a daily basis.
Can you pls provide some help here?
What brand did you get?zen2010 wrote:Sublingual Methylcobalamin (Vitamin B12), 1000 mcg, 60 Nuggets are on the way
That should be fine. Taking B12 in the morning is best as it can give you a boost of energy which could potentially interfere with your sleep if you took it in the late afternoon or early evening. Since it's a sublingual tablet, taking it with our without food doesn't matter. Just give it enough time to dissolve and then 5 minutes more before drinking or eating anything.zen2010 wrote:1- Is it ok if I take one nugget per day at breakfast time?
Every day should be fine. Have you had your blood B12 levels tested yet? B12 is water soluble so a little extra shouldn't be a problem. However, unlike other water soluble vitamins, the liver stores B12 which is why problems can take a while to show up after dietary changes that inadvertently eliminate B12, e.g., vegetarian and vegan diets.zen2010 wrote:2-Should I take it everyday for some time, and then space it a bit?
Re: B12 insufficiency/MS
Hi NHE,
Thks very much for the feedback.
The brand is Solgar
Haven't performed B12 level tests yet. As this is a safe vitamin (excess amount will be flushed out), I see no probs here.
Thks again
Thks very much for the feedback.
The brand is Solgar
Haven't performed B12 level tests yet. As this is a safe vitamin (excess amount will be flushed out), I see no probs here.
Thks again
Re: B12 insufficiency/MS
I've never tried Solgar. I once tried Jarrow, but they didn't work at all for me. I usually take Superior Source and sometimes I take Kirkland from Costco.zen2010 wrote:Thks very much for the feedback.
The brand is Solgar
Haven't performed B12 level tests yet. As this is a safe vitamin (excess amount will be flushed out), I see no probs here.
If you have any inclination to get your B12 levels tested, then hold off on the supplements or they'll give a high reading and skew the results.
Regarding safety, consider that hydroxocobalamin is used to treat cyanide poisoning and given at dosages of 5 - 10 grams via IV. 10 grams is 10,000x greater than the 1000 µg dose.
Re: B12 insufficiency/MS
The problem with B12 laboratory ranges. I recently had an opportunity to review a family member's B12 test results. The testing was done by a medical system run by a nationally known and respected local university with a medical school. Here are the ranges...
Normal: 180-914 pg/mL
Intermediate: 145-179 pg/mL
Deficient: <145 pg/mL
This exemplifies the problem discussed in the book "Could It Be B12? An Epidemic of Misdiagnoses" by Sally Pacholok. No matter how you slice it, 180 pg/mL is deficient! In fact, anything under 450-500 pg/mL is likely deficient. I would hate to be the patient with a B12 around 200 with neurological symptoms labeled as "normal" by this medical system.
Normal: 180-914 pg/mL
Intermediate: 145-179 pg/mL
Deficient: <145 pg/mL
This exemplifies the problem discussed in the book "Could It Be B12? An Epidemic of Misdiagnoses" by Sally Pacholok. No matter how you slice it, 180 pg/mL is deficient! In fact, anything under 450-500 pg/mL is likely deficient. I would hate to be the patient with a B12 around 200 with neurological symptoms labeled as "normal" by this medical system.
Re: B12 insufficiency/MS
I have in front of me two small containers of sublingual methylcobalamine 1000µg from Solgar.NHE wrote:The problem with B12 laboratory ranges.
Both were manufactured in US.
Designs of containers and labels are similar, as well as tracability patterns.
However, one was imported by Solgar France.
From the French label:RDA(Reference daily amount) of 1000µg B12 =40000%
From the American label:RDA =16667%
So ranges are differents depending on locations...
- lyndacarol
- Family Elder
- Posts: 3394
- Joined: Thu Dec 22, 2005 3:00 pm
- Contact:
Re: B12 insufficiency/MS
I believe that NHE was referring to the standard reference ranges used in the laboratories that perform the B12 blood test. When tested in the US, most labs use a cutoff point of about 200 pg/mL (According to these labs, your level must be below 200 to be considered "deficient" – this is considered to be too low by many experts.); in Japan, any patient with a level below 500 pg/mL is considered deficient and is treated as such.zen2010 wrote:I have in front of me two small containers of sublingual methylcobalamine 1000µg from Solgar.NHE wrote:The problem with B12 laboratory ranges.
Both were manufactured in US.
Designs of containers and labels are similar, as well as tracability patterns.
However, one was imported by Solgar France.
From the French label:RDA(Reference daily amount) of 1000µg B12 =40000%
From the American label:RDA =16667%
So ranges are differents depending on locations...
I do not know which cutoff point is used in France. Your doctor should have ordered vitamin B12 testing before you began taking B12 supplements.
Re: B12 insufficiency/MS
This value assumes the RDA to be 2.5 µg/day. This is close to the value that the Mayo Clinic cites as the RDA which is 2.4 µg/day. http://www.mayoclinic.org/drugs-supplem ... b-20060243zen2010 wrote:From the French label: RDA(Reference daily amount) of 1000µg B12 =40000%
This value assumes the RDA to be 6 µg/day. Many supplement companies use this value.zen2010 wrote:From the American label: RDA =16667%
If you start looking into supplement labels, then you're likely to find that the values quoted for the RDA sometimes differ from the official RDA as they're using the daily value (DV) figure.
Different countries also have different RDA values.ConsumerLab wrote:Why do DV (Daily Value) figures on food and supplement labels not coincide with the RDAs and AIs? The DVs do not necessarily reflect the latest intake recommendations from the IOM, nor do they carefully distinguish needs by age and gender, as DVs cover everyone ages 4 and up. Although the FDA has noted its intention to update the DVs, it has not done so since 1968 (aside from some additions in 1989). For reference, the DVs are shown at the bottom of each table in green. In some situations the DVs actually exceed the upper tolerable intake levels of children ages 4 to 8 (e.g., vitamin A, niacin, and zinc) and even adults (e.g., magnesium); are substantially higher than the current recommendations (e.g., chromium, copper and molybdenum) or even several times higher (e.g. biotin and chromium); or are lower than the current recommendations (e.g., vitamins C, D, and K, calcium, and potassium) or just lower than needed by women who are pregnant or lactating (e.g., iron and iodine).
Re: B12 insufficiency/MS
Time to Abandon the Serum Cobalamin Level for Diagnosing Vitamin B12 Deficiency
Abstract
Embedded Image
B12 deficiency is a common, reversible cause of macrocytic anemia and neurological symptoms. Suspected B12 deficiency can be evaluated both directly and indirectly using a variety of assays. The serum cobalamin level, despite highly variable sensitivity and specificity, is often the sole test relied upon to diagnose B12 deficiency, despite being influenced by many common medical conditions. B12 levels tend to fall late in deficiency, making it less useful in detecting acute fluctuations in body stores. In addition, assay methodology has proven problematic, with high rates of falsely normal cobalamin levels using newer chemi-luminescent technologies. Most assays also tend to measure total serum cobalamin, notwithstanding the fact that 80% of cobalamin circulates in biochemically inert form. These factors make it difficult to establish thresholds for "normal" serum cobalamin. B12 status exist along a continuous spectrum ranging from subclinically low vitamin concentrations, as observed in vegans who maintain a system of enterohepatic circulation, to fulminant deficiency with severe clinical signs and symptoms. Serum cobalamin <200 pg/mL is a threshold commonly used to delineate true deficiency, though such low levels are infrequently observed.
Methylmalonic acid (MMA), a molecular intermediate in a unique metabolic pathway requiring cobalamin as a cofactor, can be also be used to assess B12 status. MMA reflects tissue availability of biochemically active cobalamin rather than total cobalamin, with an excellent sensitivity. Fluctuations in MMA occur rapidly, and are detectable in the setting of subtle neurologic, psychiatric or hematologic signs and symptoms when corresponding serum cobalamin levels may remain normal. False positive MMA can be seen in renal dysfunction, though typically to a far milder degree than true deficiency.
To explore the operating characteristics of these serum tests in detecting clinical B12 deficiency, we retrospectively identified all MMAs measured at our institution over the 2015 calendar year and compared any elevated values with corresponding serum cobalamin levels drawn within the same week. 34 of 42 (81%) elevated MMAs were associated with a serum cobalamin level within our laboratory's reference range, and six (14%) of these were actually greaterthan the upper limit of normal. Acknowledging the limited size of our data set, this translates to a 19% sensitivity of serum cobalamin for detecting elevations in MMA and, by extrapolation, detecting clinical B12 deficiency. This sensitivity is far lower than that commonly reported in the literature.
Despite the superior test characteristics of MMA, serum cobalamin is often the first and only test performed to evaluate B12 status due to "economic" reasons or force of habit. If only the cobalamin level were relied upon, many patients would go untreated for a curable disease. While the cost difference of serum cobalamin and MMA assays at our hospital ($7.00 and $18.00, respectively) is not negligible, the time and expense of repeated cobalamin measurements or other testing necessary to accurately diagnose B12 deficiency is arguably greater. The mass of accumulated data shows that serum cobalamin is an insensitive assay for B12 deficiency and should be abandoned. MMA is superior for detecting diminished functional B12 stores; increased utilization of this test will result in more accurate and cost-efficient diagnosis of true B12 deficiency.
Disclosures Taylor: Baxalta/Shire: Consultancy, Research Funding; Novo Nordisk: Research Funding; Kedrion: Research Funding; CSL Behring: Consultancy, Research Funding.
↵* Asterisk with author names denotes non-ASH members.
Embedded Image This icon denotes a clinically relevant abstract
© 2016 by The American Society of Hematology
http://www.bloodjournal.org/content/128 ... ecked=true
Abstract
Embedded Image
B12 deficiency is a common, reversible cause of macrocytic anemia and neurological symptoms. Suspected B12 deficiency can be evaluated both directly and indirectly using a variety of assays. The serum cobalamin level, despite highly variable sensitivity and specificity, is often the sole test relied upon to diagnose B12 deficiency, despite being influenced by many common medical conditions. B12 levels tend to fall late in deficiency, making it less useful in detecting acute fluctuations in body stores. In addition, assay methodology has proven problematic, with high rates of falsely normal cobalamin levels using newer chemi-luminescent technologies. Most assays also tend to measure total serum cobalamin, notwithstanding the fact that 80% of cobalamin circulates in biochemically inert form. These factors make it difficult to establish thresholds for "normal" serum cobalamin. B12 status exist along a continuous spectrum ranging from subclinically low vitamin concentrations, as observed in vegans who maintain a system of enterohepatic circulation, to fulminant deficiency with severe clinical signs and symptoms. Serum cobalamin <200 pg/mL is a threshold commonly used to delineate true deficiency, though such low levels are infrequently observed.
Methylmalonic acid (MMA), a molecular intermediate in a unique metabolic pathway requiring cobalamin as a cofactor, can be also be used to assess B12 status. MMA reflects tissue availability of biochemically active cobalamin rather than total cobalamin, with an excellent sensitivity. Fluctuations in MMA occur rapidly, and are detectable in the setting of subtle neurologic, psychiatric or hematologic signs and symptoms when corresponding serum cobalamin levels may remain normal. False positive MMA can be seen in renal dysfunction, though typically to a far milder degree than true deficiency.
To explore the operating characteristics of these serum tests in detecting clinical B12 deficiency, we retrospectively identified all MMAs measured at our institution over the 2015 calendar year and compared any elevated values with corresponding serum cobalamin levels drawn within the same week. 34 of 42 (81%) elevated MMAs were associated with a serum cobalamin level within our laboratory's reference range, and six (14%) of these were actually greaterthan the upper limit of normal. Acknowledging the limited size of our data set, this translates to a 19% sensitivity of serum cobalamin for detecting elevations in MMA and, by extrapolation, detecting clinical B12 deficiency. This sensitivity is far lower than that commonly reported in the literature.
Despite the superior test characteristics of MMA, serum cobalamin is often the first and only test performed to evaluate B12 status due to "economic" reasons or force of habit. If only the cobalamin level were relied upon, many patients would go untreated for a curable disease. While the cost difference of serum cobalamin and MMA assays at our hospital ($7.00 and $18.00, respectively) is not negligible, the time and expense of repeated cobalamin measurements or other testing necessary to accurately diagnose B12 deficiency is arguably greater. The mass of accumulated data shows that serum cobalamin is an insensitive assay for B12 deficiency and should be abandoned. MMA is superior for detecting diminished functional B12 stores; increased utilization of this test will result in more accurate and cost-efficient diagnosis of true B12 deficiency.
Disclosures Taylor: Baxalta/Shire: Consultancy, Research Funding; Novo Nordisk: Research Funding; Kedrion: Research Funding; CSL Behring: Consultancy, Research Funding.
↵* Asterisk with author names denotes non-ASH members.
Embedded Image This icon denotes a clinically relevant abstract
© 2016 by The American Society of Hematology
http://www.bloodjournal.org/content/128 ... ecked=true
Re: B12 insufficiency/MS
In addition, a false negative MMA test, low MMA in the presence of B12 deficiency, can occur if a patient is taking, or has recently taken antibiotics. This could lead doctors to incorrectly rule out a true B12 deficiency.THX1138 wrote:Time to Abandon the Serum Cobalamin Level for Diagnosing Vitamin B12 Deficiency
Methylmalonic acid (MMA), a molecular intermediate in a unique metabolic pathway requiring cobalamin as a cofactor, can be also be used to assess B12 status. MMA reflects tissue availability of biochemically active cobalamin rather than total cobalamin, with an excellent sensitivity. Fluctuations in MMA occur rapidly, and are detectable in the setting of subtle neurologic, psychiatric or hematologic signs and symptoms when corresponding serum cobalamin levels may remain normal. False positive MMA can be seen in renal dysfunction, though typically to a far milder degree than true deficiency.
What about the costs to the patient who suffers irreversible neurological damage from an undetected B12 deficiencyTHX1138 wrote:Despite the superior test characteristics of MMA, serum cobalamin is often the first and only test performed to evaluate B12 status due to "economic" reasons or force of habit. If only the cobalamin level were relied upon, many patients would go untreated for a curable disease. While the cost difference of serum cobalamin and MMA assays at our hospital ($7.00 and $18.00, respectively) is not negligible, the time and expense of repeated cobalamin measurements or other testing necessary to accurately diagnose B12 deficiency is arguably greater.
Re: B12 insufficiency/MS
Here’s an interesting article on B12 and folate. It discusses the problems with low B12 and unsupplemented high B12.
https://labs.selfdecode.com/blog/vitamin-b12-test/
https://labs.selfdecode.com/blog/vitamin-b12-test/