**EP423: Why Vitamin B12?**
**Dr Warrick Bishop:** Welcome, my name is Dr Warrick Bishop. I'm a cardiologist, an author, and a keynote speaker. I'm CEO of the Healthy Heart Network. I'm all about trying to help people live as well as possible for as long as possible. Heart disease is huge in Australia. Every 20 minutes, someone suffers a heart attack. Most of these could probably have been avoided if only we knew what to do. This podcast is all about helping you understand blood pressure, weight, cholesterol, for better health. If you enjoy this podcast, I would be honoured for a five-star review. You can share it with your family and friends. It may well save someone you love.
**Dr. Warwick Bishop:** G'day. My name's Dr. Warwick Bishop, as you probably guessed, and I'd like to welcome you to my podcast and videocast station. So, for those who are listening, I do have this recorded as a video as well, so you can check that out on YouTube if you're interested. I'd like to thank you, as always, for taking the time to listen. It really means a lot to me if I'm putting content out there and people are enjoying it.
Today I'm going to be talking about vitamin B12. Vitamin B12. You may have heard of it. It is important; we need vitamins for all sorts of cellular functions in our body. So let's talk about B12. Well, it supports red cell formation. We know from when we take blood tests, if we look at the size and the shape of a red blood cell or red corpuscle, if it's a bit large and it's spherical rather than discoid, that can be a sign of B12 or folate deficiency. B12 and folate are really important for DNA synthesis and the way the body represents the proteins that are coded by the DNA. So if we see an abnormal red blood cell that's slightly bigger and round, we know that that may well be linked to B12 or folate deficiency.
DNA synthesis requires B12. B12 is critical for healthy brain function. We think about B12 and folate supplements during pregnancy for women. It's also really important for nerve function because loss of B12 can lead to peripheral neuropathy or distal nerves not working properly. It also helps with energy metabolism. So some people will report a sense of improved energy and physical capacity if given B12 as a supplement.
Meaning, how do we detect a deficiency or indicators of low B12? Well, to be honest, if you're finding that you're waiting for symptoms to determine if your B12 is low, you might be waiting a bit too long. I highly recommend you think about including a B12 level on the next blood test that you request with your GP if you're having screening bloods. Include that in there, maybe with something like vitamin D.
But if you were to let your B12 run low, you might notice fatigue or weakness. One of the things that is described is an inflamed or a sore tongue. The word we use for an inflamed tongue is glossitis, like, well... like a sauté. Weight loss and appetite change can be a feature. If that peripheral neuropathy progresses, which is a really late stage and you really want to be picked up before, then you might notice tingling, particularly in the feet. That will also mean that other nerves, things that control gait, might be impacted as well.
Who could be at risk? Well, because B12 in particular tends to come from animal products, we know that vegetarians and vegans can be at risk. People, though, who are used to being vegetarian or vegan have generally done a bit of reading and are well-informed, and so will look to B12 supplementation to make sure that doesn't occur. But that is linked, so do be aware if you are vegetarian or vegan.
Older adults, because absorption may be reduced, and we tend to eat less as we get older as well. So there's the possibility that less intake and less absorption could lead to problems. Well, because we need to absorb the vitamin, problems with the gut, the gut lining can impact. Conditions like Crohn's disease, which is an inflammation in different parts of the small bowel, large bowel, or anywhere in the gastrointestinal tract, could impact the absorption of B12 if it's affecting the small bowel.
Celiac disease, so that condition that occurs in direct relation to the microvilli of the small intestine being damaged by gluten, could also affect B12 absorption. Gastric bypass, because the stomach, believe it or not, produces this amazing chemical called intrinsic factor, a molecule, and that intrinsic factor binds to B12 to improve its absorption in the small bowel. So if you've got a gastric bypass or you've had your small bowel resected, you may not have the equipment to absorb or digest and absorb B12.
Long-term users of proton pump inhibitors, these are the antacid-type agents that people use; we're thinking things like Nexium, which you may be familiar with. These can alter gastric function and therefore reduce the presence of intrinsic factor. Metformin also has been linked to lower levels of B12. So if any of those sort of touch a note with you, have a chat with your GP and do make sure you get that B12 checked.
Well, when we do find someone who's got a deficiency, you can give reasonable doses and it's pretty safe. 1,000 micrograms per day of cyanocobalamin can be given orally, and then you check and follow up. That's assuming that there isn't a gastric reason for the individual not absorbing B12. B12 can be given as an injection, and for someone who's got symptoms in particular, particularly neurological symptoms, you want to get that B12 in as soon as possible.
So injection, which can be intramuscular (a little bit painful) or into the vein, is very effective with 100% bioavailability. It can be done if there's a concern around symptoms. And look, it's pretty safe. It's very hard to overdose on unless you're doing something really very silly, but it's got a huge therapeutic window.
One of the things that comes up is discussions around B12, which is called cobalamin. And there's questions as to whether you should have methyl. What that means is the cobalamin B12 is either linked with a methyl group or a cyano group, and these are slightly different. They're worth knowing about. Methylcobalamin is the methylated form, and it's the active form of B12. It works immediately and is able to be utilized, particularly if someone had a neurological symptom, for example, you'd want to get that into them as soon as possible.
Cyanocobalamin is a synthetic form and that has to be converted to the active form, so the body needs to do that conversion. Remember, cyanocobalamin contains cyanide, but it's in very small amounts. It sort of plays a little bit with your mind. Methylcobalamin, as I said, can support neurological function directly.
Well, we've talked about people taking it orally, but what if you do have to take it parenterally, either as an injection or into the vein? Well, if you do have problems with the stomach or small intestine, then IV makes a lot of sense. We know that IV is really good for replenishment of severe deficiency, particularly if symptoms are present. So that gives you the chance to replenish very quickly.
And the really nice thing about running an IV infusion with B12 is you could combine it with other agents. Things like vitamin C to act as an antioxidant. Things like glutathione, which also acts as an antioxidant. But you might also give things like magnesium, which are fantastic for helping over 300 different biochemical reactions within the body and will support the positive effects of the B12. So it's a great way to get a horse bolus of good stuff in.
You may have heard of the methylene tetrahydrofolate reductase gene or mutation. So I'm going to touch on that. There is an MTHFR gene that affects folate and B12 metabolism. It really is a gene, and it's a common deficiency where people may not be able to convert B12 effectively. These individuals in particular really should be taking methylcobalamin, as that is preferred because it's already methylated and ready to go for those individuals.
This can be really important because some of these individuals will suffer mood disorders and fatigue, and that B12 will help them replenish those stocks, which is a really valuable thing for their best health. So, methylene tetrahydrofolate reductase, how often does it occur? Well, up to 40% of the population. There are a number of specific genes that have been identified, and you can actually get tested for that, and it obviously therefore runs in families because it's genetic.
The individuals with it can struggle to convert B12 into the active form that's needed for the body to use. So cyanocobalamin may not actually do the job for these people. It's interesting and worth being aware of.
Where does it fit in clinical practice? Well, I think it's very sensible to consider monitoring B12, particularly as part of your regular blood tests. If it is low, you really need to speak with the GP to understand why. If it's related to gut-related issues and you're looking to top that up, then injections, whether that's into the muscle (a little bit painful) or into a vein (a little bit less painful with the opportunity to give other wonderful vitamins and minerals with it), is certainly worth considering.
What's really important, though, is that you know it's there and that perhaps you ask your doctor about it and understand it a little bit more. If, for example, you are one of the methylene tetrahydrofolate reductase individuals who are missing the gene, that's also really worth knowing. So some information to check out with the rest of the family.
For now, I'm going to wrap up. I am going to wish you the very best. I do hope you live as well as possible for as long as possible. And if you've got any queries or questions, drop us a note, even for Dr. Warwick Bishop online. I would love it if you would subscribe to this podcast, please. And I'd love it if you'd share it and encourage someone else to have a listen. I hope you found today interesting. I find it fascinating.
Till next time, all the very best. Take care and bye for now.
Join the Healthy Heart Network and become part of our growing community. If you're interested in your heart health and risk of heart attack, then join the Healthy Heart Network for only $5 as a lifetime member. This represents $55 worth of value. We offer and help people understand their present state of heart health, what their current level of risk is, and the positive steps they can take to improve their risk of heart attack in the future. Go to www.healthyheartnetwork.com.au and click the "Join the Family" button.
