Is it possible to get too much cobalt from frequent injections of hydroxycobalamin eg 1ml every 2 weeks especially if you orally supplement as well with high dose daily sublinguals say 5000 micrograms from superior source?
Just wondered if cobalt poisoning was something to be worried about.
short answer is that it supplementation with B12 is not going to cause cobalt poisoning.
Some people are allergic to cobalt - one reason why initial loading shots should be under medical supervision - but this is extremely rare.
The cobalt in cobalamin (B12) is very tightly bound in a molecule and very difficult to get out of the molecule. Risks of cobalt poisoning are from sources of cobalt that isn't bound in this way but is ingested just as cobalt.
medlineplus.gov/ency/articl...
Please see this article from the pinned posts on the safety of B12 treatments
stichtingb12tekort.nl/weten...
Let's look at some numbers. How high a blood level of B12 does one get from supplementing? I would say that 1000 ng/L would count as fairly high. That's 1 ug/L.
Each ug of B12 contains 50 ng of cobalt (a B12 molecule is mainly other atoms). So a fairly high B12 level would give you 50 ng/L of cobalt.
The biggest exposure to cobalt, apart from industrial exposure, is people with artificial joints. The medical profession has decided that blood levels of cobalt under 5 ug/L are acceptable.
So a high serum B12 of 1000 ng/L will give cobalt levels of 100 times less than is acceptable from a hip replacement.
Add in Gambit62 's valid points about the cobalt in B12 being locked up in the molecule makes the safety margin even higher.
Even taking much larger amounts of B12 isn't going to raise B12 levels too much, because the kidneys remove all B12 from the blood, then reabsorb it (yes, it's a silly system and a great argument against intelligent design). But the reabsorption has a limit. Only a certain amount can get back into the blood. So there is a limit to how much B12 can be in the blood, which limits the amount of Cobalt from B12 in the blood.
And that limit is way lower than what is acceptable from a hip replacement.
Thanks for the information. I asked the question because of a comment I received in/ via a circulated email from another PA person who had attended a conference in Colorado where it was suggested that some children who were given high injected doses (not sure why) of around 2000mpg a day suffered toxicity of the liver. See relevant bit below. I just wondered about the cobalt side of things. I think our doses are probably safe. I have copied in the section that alerted / worried me.
Have you heard via the PAS website that they are looking into pushing patients down the high dose oral route? I worry that this is not going to be as good as injection. I probably worry too much!!!!! part of the condition - anxiety!
FASEB conference in Colorado
B12 levels in children differ by age, some are way, way higher than those normally found in adults. Research by a lady called Annelise Bjork-Monsen.
There is a possibility that very high doses of injected B12, like 2000 mpg daily, can lead to cobalt toxicity in the liver. Cobalt of course is a heavy metal, and the centre of the B12 molecule. That is the first I have ever heard of toxicity by vitamin B12. I haven’t read the original article yet. This is very different from oral B12, because only c. 1% of oral doses is absorbed [even by people who do have intrinsic factor, because absorption by IF is very limited in itself].
Nope, I can't find anything about high B12 causing liver problems. But it is well known that liver problems can cause abnormally high B12.
It sounds like cause and effect may have been swapped.
Can't find anything on that from Anne-Lise Bjørke-Monsen (as her name is) that suggests that. Yes, B12 levels being higher and she wrote articles on MMA/homocysteine in children. Did the email give a specific article?
I think you've had some very sound responses from Gambit and fbirder. I very much doubt any of us are at risk from our treatment. Did you know that cobalamin is the only vitamin with a metal as part of its matrix?
I'm probably absorbing tiny amounts of cobalt from the big shiny NHS crown on an upper left molar. The dentist said cobalt was part of the alloy, which he had to specify, because I'm allergic to the standard nickel component. He's a decent bloke, who lost NHS fees in the laborious attempt to save my crumbling tooth, so I trust him!
Free elemental cobalt may well be another matter. I've had some exposure to this through art materials, and in the past I haven't always been very careful. Among other problems, it can cause contact dermatitis.
Help with co-factors to help B12 to work
Reaction to B12 tablets 
Do the oral B12 sprays definitely work for patients with positive anti-body for intrinsic factor?
Can B1 (Thiamine) improve B12 d as a co-factor (along with folate?)
Intrinsic Factor Pills + B12 + Folic acid combination tablets for PA. Does it work?
