Pernicious Anaemia Society
14,228 members10,192 posts

Nox and B12

We have been unundated by stories in the media about Volkswagen group vehicles releasing more nitrogen oxides in the real world than in tests. We have also seen many stories about rising Nox levels in our cities. And the third element, we have often read that nitous oxide, often used as an anaesthetic, depletes B12 levels.

The obvious question that comes from the above: Do nitrogen oxide pollutants affect human B12 levels?

I am not finding any useful research - but maybe I am just missing it all!

4 Replies

Fossil fuels contain carbon, nitrogen, oxygen and hydrogen in varying quantities.

When you burn the fuels and release energy this results in producing oxides - carbon dioxide, carbon monoxide, nitrogen oxide, nitrous oxide (nitrogen di-oxide = laughing gas = the anaesthetic that oxidises B12), hydrogen oxide (water) ...

carbon dioxide is the most prevalent result.

The amounts being produced are relatively small in comparison the the amount that is in the air anyway.

Think you'd probably need to be actually sniffing the exhaust pipe to get significant quantities of nitrous oxide and strongly suspect that the carbon monoxide would have got to you long before the nitrous oxide had a chance to do anything.

So, yes, a health hazard but not a significant one at the levels you are going to experience walking down the street.

Can't find easily any figures on actual concentrations but these are links to the standards that apply in the US

and APIS in the UK (research on air pollution)

1 like

Thanks Gambit.

People who do not have problems with B12 seem to need around 3 micrograms a day.

The molar mass of B12 is 1355.37 g/mol - and that of nitrous oxide is 44.013 g/mol. So if we are talking of one molecule of nitrous oxide reacting with one of nitrous oxide - 3 micrograms of B12 would only need 0.097 micrograms of nitrous oxide! That is a tiny amount. (Anyone care to give my working out a sanity check?)

If we were absorbing sufficient nitrogen oxides each day to cancel out the typical daily B12 usage, how long before we would suffer from at least slightly low B12?

From the figures, I cannot see how to even guess the amount of nitrogen oxides that could be absorbed in a day at any given concentration in parts per billion.


The amounts are very small and to do all the maths you'd need to be looking at average breath size, absorption in the lungs etc etc.

The EPA site quotes 53 particles per billion in air as the harmful concentration - which looks about right - and says nowhere in the states has been identified as having that level - and it really would be quite a lot of nitrous oxide - come back to needing to have your nose up the exhaust pipe ... and other pollutants - much more fast acting - would get to you long before nitrous oxide had a chance to have any significant effect on B12 levels.


53 ppb is about 99 µg/m3 for NO2.

In Camden, we have seen levels way over 58 ppb. E.g. 211 µg/m3 (around 112 ppb).

I was deliberately fuzzy about which oxides of nitrogen - I have no idea of the effect of any of them on B12 other than nitrous.


You may also like...