Hello theresej,

Please be very careful about self-diagnosis of B12 deficiency.

I understand that many members of this forum are probably here because they have not been able to get the help that they need from medical professionals. I cannot blame anyone for wanting to "do it yourself"; if you read About Me on my web site, you will understand why.

Until May this year, I was unable to find a doctor who either knew or cared about vitamin B12 deficiency (except for my psychiatrist). I am very fortunate to now have a doctor who is interested in nutritional and holistic medicine.

It would be best if you could find a local doctor who knows about nutritional disorders.

I am torn between wanting to give advice, and the need to be cautious; I am not medically qualified. I do have tertiary qualifications in applied science and engineering, with my main interest in scientific instrumentation. While I am competent to design scientific experiments and analyse the results, including my current series of tests, all that I know about B12 deficiency comes from two years of reading about it on the Internet.

Although I cannot offer medical advice, I can offer to share my research findings with anyone who is interested. This is partly why I have published my web site. The References page contains direct links to many articles; this is intended to be a resource for others to use.

Having said all that, I will respond to the specific issues that you raised:

1. You used the change in homocysteine to diagnose your B12 deficiency. There are potentially some serious problems with this:

• Homocysteine can be affected by either vitamin B12 or by folate. Just as it is possible to mask B12 deficiency by using folate supplements, it is possible to mask a folate deficiency by taking large doses of B12. Because of the complex chemical interaction between homocysteine, folate and B12, it is possible that the reduction in homocysteine level does not confirm a vitamin B12 deficiency.
• You should be very careful about relying on just two measurements. Homocysteine is susceptible to very significant variations between measurements. Even if you maintained a perfectly stable diet, lab errors can be a major problem. As reported on my web site, different labs reported huge differences for the same sample, and there were unexplained variations between consecutive samples from the one lab.
• Methylmalonic acid is a much more specific marker of vitamin B12 deficiency because it is not affected by folate levels. As you have commenced taking B12 supplements, there is no point in measuring MMA now.

I strongly suggest that you have your red-cell folate measured, if you have not already done so, otherwise you cannot draw any conclusion from your observation, and could be at risk of folate deficiency.

2. You did not give the units for your B12 level of 750. Some labs still report in pg/ml (ng/l) while others have changed to the SI unit of pmol/l. If your result was in pg/ml then you can convert it to pmol/l, as follows:

• (Concentration in pg/mL) x (0.7378) = pmol/L

So, if your result was 750 pg/ml, it is equal to 553 pmol/l; any lab would report that result as normal. Although this does not exclude the possibility of vitamin B12 deficiency, your level is way above what is normally the "grey zone". I suggest that you read the article by Oh and Brown, which is reference G1 on my References page. In the same section, B12 Deficiency - Diagnosis, you will find several articles that are useful.

3. Until recently, methylcobalamin was not readily available here in Australia, so all my testing has been done with cyanocobalamin. There have been many comments on forums about how methylcobalamin has been found to be more effective. This is reported to be because the cyano form requires conversion to the methyl form in the body. There are links to several articles on oral treatment of B12 deficiency in the B12 Deficiency - Treatment section of my References page.

4. I am not sure what you mean by "the neurologically active form, methyl-B12". You appear to have made a connection between the form of oral dose and the neurological effect of a deficiency. I would expect the cyano form to correct a deficiency, regardless of the symptoms, although with less efficiency than the methyl form. Similarly, I would expect the methyl form to correct a deficiency that has only haematological symptoms.

5. I agree that most doctors do not have a clue.

I suggest that you do all of the following:

• If you have not done so already, check for the possibility of folate deficiency by having your red-cell folate measured.
  
• As you have already started., continue taking the B12 supplements unless you become certain that you do not have vitamin B12 deficiency.
  
• Search for a doctor who specialises in nutritional or holistic medicine.
  
• Read as much about B12 deficiency as you can, especially the findings of researchers, starting with reference G1 on my web site.
  
• Before accepting advice that you either do or do not have a B12 deficiency, ask “what is the evidence?”. Remember that is that there is currently no agreed “gold standard” test for vitamin B12 deficiency. You will have to make a decision based on the imperfect tests that are currently available.

Paul