CAN YOU TAKE TOO MUCH VITAMIN B12?

Let me at the top indicate that medical science mostly says you can't really take too much Vitamin B-12.  For example, the Food and Nutrition Board has not established a Tolerable Upper Intake Level because it feels this is not necessary.  And sorry about this lengthy posting, but I thought you should see the entire Quora presentation.

Keep in mind that the human body does not naturally produce its own vitamin B12:

• We obtain B12 from meat, fish, dairy, eggs and supplements.
• Bacteria in the large intestine can produce a small amount of B12, but the colon cannot absorb it.
• The recommended daily amount needed by the body is around 2.4 micrograms (mcg) per day.
• Note that those supplements you take are in the 500 mcg to 2500 mcg size tablets, which is taken daily is because your body is very inefficient in utilizing this vitamin.  What is not used passes through your digestive system.
• The older you get, B12 from the food you eat becomes insufficient, and you are advised to take these supplements.  

A year and a half ago I began to lose stamina when I walked any distance.  I mentioned this to my doctor, and he advised me to take a 500 mcg tablet of Vitamin B12 daily.  I did, and blood samples showed that the low B12 reading rose to a middle of the band level.  More importantly, I now don't get fatigued when I walk a mile.

Vitamin B12 supplements come in sizes from 50 mcg to 5000 mcg, with 1000 mcg a standard high-potency dose.  The first bottle I bought began to run out, so I went to Costco, and saw that they only had bottles of 1000 mcg and 5000 mcg tablets.  I had read where you can't really take too much of B12, so I bought 400 1000 mcg pills.  A couple of months later, my blood test showed the B12 reading rose a little higher, but was still well within the safe band.

Then a few days ago I was shocked to see this in Quora:

Matthew Kireken

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Former Doctor Who Genuinely Loves People6mo

Why is vitamin B12 so dangerous?

Most people are going to hate this but its the truth, please forgive me if I happen to offend you but I would rather speak the truth and save your life. Vitamin B12 also called Cobalamin is extremely dangerous, if and only if...Please note the if. It is dangerous when you take too much of it. I am speaking from experience by the way. Not just my experience but many of my patients have been hit by these problems. And please don't say it doesn't matter because it is water soluble, it may be water soluble but it doesn't mean it's not harmful if you take too much. Here's what happened to me and what can happen to you if you go absolutely nuts with B12 thinking more is always better...

The 8 nasty things that can happen if you take too much of Vitamin B12 (also called Hypercobalaminemia - excessive supplementation):

1. Your face breaks out like a 14 year old (teenager - I'm talking painful cystic acne that comes out of nowhere, especially around your jawline. This happened to me, it was so awful, I would not want anyone to go through that at all.
2. Anxiety and jitters that make you feel like you've had way too much coffee - your heart starts racing for no reason. It really messes up your mood, many patients who over-supplement, show this side effect.
3. Insomnia hits hard - you're lying there wired at 2 in the morning even though you're exhausted.
4. Weird allergic reactions like hives, itching, or even trouble breathing in some people. I stopped having this after 2 weeks of fixing my Vitamin B12 intake.
5. It can mess with your potassium levels and cause muscle cramps or weakness. The cramps are so painful by the way. I would scream because of the pain. I love you too much..please take the right doses to avoid this.
6. Nausea and stomach upset that makes you feel like garbage. It is so horrible, some get this while others do not. But it is a super horrible feeling.
7. Headaches that just won't quit - like this dull throbbing that follows you around. My wife would also experience this one. By changing her dosage she began to feel so much better.Your B12 daily allowance could be the reason why you get headaches…just saying, the moment you start taking the right amounts, you may notice no more headaches. Just give it a TRY.
8. It can actually hide other vitamin deficiencies, especially folate, so you think you're fine but you're not

Please note that B12 isn't dangerous at all if taken in the right amounts. Most people are walking around completely clueless, unaware that they need not take too much but the right amounts of Vitamin B12. There's this woman I know, she's about my age - I'm pushing 60 and she kept saying she felt like garbage all the time, she couldn't remember simple things, it’s really so sad... turns out her B12 intake was way over the roof. The problem with many people is, once people figure out they're deficient, they go absolutely nuts with these massive doses thinking if a little is good, a ton must be amazing. WRONG...Too much is definitely toxic. Personally, I take about 1000 units every single day because let's face it, when you get older your gut just doesn't absorb stuff like it used to.. But I always make sure that i don't take too much...

The 5 good things when you take it right (you will experience this if you take the right amounts of B12):

1. Your energy comes back without the crash - steady, real energy all day long….The feeling is so amazing
2. Brain fog lifts and you can actually think clearly again. No more forgetting simple things, say hello to good sharp memory
3. Your mood stabilizes - no more random depression episodes. This will benefit your loved ones and those around you. Good mood is equal to good day.
4. Nerve pain and tingling goes away completely. No more pins and needles. The pins were so painful for many of my patients. Horrible pain.
5. Your sleep actually becomes restful instead of just passing time.

To get these benefits without the nightmare: Stick to 1000-2500mcg (micrograms) daily max, take it in the morning with food, and don't go crazy with those 5000mcg+ doses unless a doctor, the one who truly cares tells you to. Some docs lack nutritional knowledge by the way, trust your instincts, some are not your friends I learned this the hard way - took mega doses for a month and broke out like I was fifteen again. I suffered because I did not know the aforementioned, just like many, I thought too much was good but a wise man knows too much is not good, even too much water causes (hyponatremia) - it’s not a good thing...Too much water, less sodium, CAN be fatal, the same is too for too much Vitamin B12. Ok so out of 10, I give sensible B12 use an 8, but overdoing it gets a big fat 2... You go from fixing a real problem to creating new ones that didn't need to exist. So stick to moderate amounts.

Don't listen to the too much is not harmful narrative, remember Big Phar** is not your ally. They want you sickkkkkk. I am here to expose them. I am here to help, because I care.

First, he takes 1000 mcg, which apparently is what he prescribes to his patients.  So 1000 mcg must be fairly safe.  However, here is what he says happens when you take too much of B12:

• Your face breaks out in acne.  Surely enough, for the past two months I have had several pimples, for the first time in many decades.  I'm 85 years old.  Worse, these cysts seem to form keloids.
• More anxiety and jitters.  Yes, I think I'm now more on edge.
• Insomnia hits hard.  For the past couple years I've more trouble sleeping, but recently, I've been doing well.  So not this problem.
• Weird allergic reactions like hives, itching and trouble breathing occurs.  If anything, I've suffered minimally from these symptoms.
• More muscle cramps.  Nope, not this one.
• Nausea and upset stomach.  A little bit of this, but I've always had some gastritis, so nothing new.
• Headaches.  Not this.
• Hides other vitamin deficiencies.  Not sure of this.

My sense is that Dr. Kireken is talking about those people who take as much as 5000 mcg or more, for he actually prescribes dosages of 1000 to 2500 mcg tablets/daily.  But maybe my body is such that even "only" a 1000 mcg pill/day schedule might be too much for me.  So yesterday I bought a bottle containing 100 500 mcg B12 tablets.

• Cost $7.
• Google Ai indicates that these pills general cost from $4 to $10 for a bottle that has from 100-300 tablets.  A huge range.
• Interesting that the 500 mcg tablets cost more than the 1000 mcgs.  
• Also Walgreens, CVS and Target have all kinds of deals, like Buy 1, get 1 free.  The CVS store I went to also had these sales, but not for the 500 mcg tablets.

There was another point that was confusing me.  From Google AI:

Vitamin B12 is often cited as ~2.4 mcg (micrograms) for daily, healthy intake, but sold in 1,000 mcg doses because the body has limited absorption capacity for B12. High-dose supplements (1,000 mcg) bypass inefficient absorption, ensuring enough gets into the bloodstream, especially for those with deficiencies or absorption issues. 

• So be clear, your body can use 2.4 mcg daily, but you need to take a 1000 mcg dose daily because your body is very inefficient in absorbing this vitamin.  

I then went to an article from the Cleveland Clinic.

• Experts suspect that B12 deficiency is common, and could effect up to 2 in 5 people worldwide.  This deficiency gets worse with age.
• Vegetarian and vegan diets can cause B12 deficiency.
• Chances are low that you will suffer from those symptoms shown above because your body does not absorb excess B12.  In one case, a person had 15,000 mcg of B12 injected into her over several weeks to suffer from any symptoms.
• Vitamin B12 is in many animal-based food sources, but eat all you want, for your body cannot actually use much of it, eliminating most of it from your poop or pee.
• There are several ways to develop high vitamin B12 levels, some much easier than others. And while this condition isn’t dangerous, there’s evidence that it may be something you want to resolve sooner rather than later.
• Some medical condition can interfere with how your body processes B12.  Some examples include liver and kidney disease/failure, pernicious anemia, Crohn's disease and blood cancers.
• The only solution for too high B12 levels is to stop taking B12 pills or reduce the amount.
• Fortunately, B12 doesn’t cause permanent harmful effects if you have too much of it. Symptoms are rare, though they can be unpleasant. But they’ll go away if you don’t get more B12 than your body can process.

So dropping down to 500 mcg/day should be good for me, I hope.  My next blood test is 5 months away, but if I retain my stamina when walking, I should be fine.  Hopefully the pimples will disappear.

Yesterday was a great day for Team USA in the 2026 Winter Olympics.  Today, not so good, with a  terrific exception, maybe even incredible.

The 2026 Winter Olympics medal count by country as of February 19

1. Norway: 34 (16 gold, 8 silver, 10 bronze)
2. Italy: 26 (9 gold, 5 silver, 12 bronze)
3. US: 26 (8 gold, 12 silver, 6 bronze)
4. Japan: 22 (5 gold, 6 silver, 11 bronze)
5. Germany: 21 (5 gold, 8 silver, 8 bronze)
6. France: 19 (6 gold, 8 silver, 5 bronze)
7. Austria: 18 (5 gold, 8 silver, 5 bronze)
8. Netherlands: 16 (6 gold, 7 silver, 3 bronze)
9. Sweden: 15 (6 gold, 6 silver, 3 bronze)
10. Canada: 15 (4 gold, 5 silver, 6 bronze)
11. Switzerland: 14 (6 gold, 4 silver, 4 bronze)
12. China: 10 (3 gold, 3 silver, 4 bronze)
13. Korea: 7 (2 gold, 2 silver, 3 bronze)
14. Austria: 6 (3 gold, 2 silver, 1 bronze)
15. Finland 5 (1 silver, 4 bronze)
16. Czech: 4 (2 gold, 2 silver)
17. Slovenia: 4 (2 gold, 1 silver, 1 bronze)
18. Poland: 4 (3 silver, 1 bronze)
19. Great Britain: 3 (3 gold)
20. New Zealand: 3 (2 silver, 1 bronze) 

And, by the way, here are the medal events today.

Thursday, February 19 - 7 events, 21 medals

1. Men's Ski Mountaineering - Sprints 
2. Women's Ski Mountaineering - Sprints
3. Men's Freestyle Skiing - Aerials 
4. Men's Nordic Combined - Team Large Hill: 2x7.5km relay 
5. Women's Hockey (Bronze: Switzerland vs. Sweden; Silver/Gold: USA vs. Canada)
6. Men's Speed Skating - 1500m 
7. Women's Figure Skating 

Oh, heck, here are the medal events for the rest of these Winter Olympics.  Note that Team USA has not qualified for medals in most of these competitions.

Friday, February 20 - 7 events, 19 medals

1. 
   Women's Freestyle Skiing - Cross
2. Men's Biathlon - 15km Mass Start 
3. Women's Speed Skating - 1500m
4. Men's Curling (Bronze only)
5. Men's Freestyle Skiing - Halfpipe 
6. Women's Short Track - 1500m
7. Men's Short Track - Relay 

Saturday, February 21 - 11 events, 29 medals 

1.  Mixed Team Freestyle Skiing - Aerials 
2. Men's Cross-Country Skiing - 50km Mass Start Classic
3. Men's Freestyle Skiing - Cross 
4. Mixed Team Ski Mountaineering - Relay 
5. Women's Curling (bronze: Sweden vs Canada and Switzerland vs USA in semifinals on Friday, losers play today)
6. Women's Biathlon - 12.5km Mass Start 
7. Men's Speed Skating - Mass Start
8. Women's Speed Skating - Mass Start 
9. Women's Freestyle Skiing - Halfpipe
10. Men's Hockey (USA plays Slovakia in the semifinals, 3:10 PM ET on Friday, and will play a bronze medal game if they lose)
11. Two-Woman Bobsleld

Sunday, February 22 - 4 events, 10 medals

1. Women's Cross-Country Skiing - 50km Mass Start Classic 
2. Women's Curling (Team USA could be playing in this Silver/Gold medal game if they beat Switzerland on Friday) 
3. Four-Man Bobsled
4. Men's Hockey Final (if Team USA beats Slovakia, they will play the winner of the Canada-Finland semifinal game for the Gold) 

Also, the Closing Ceremony will be televised Sunday on NBC and Peacock beginning at 2:30 PM ET (9:30 AM Hawaii time).

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