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How Much Vitamin B12 Should We Take & Why? Dr Joel Fuhrman

August 20, 2019

Vitamin B12 is a water-soluble vitamin which
means it dissolves in water and travels through our bloodstream and this can be a good thing
because if we take too much it means that any excess or unwanted amounts are excreted
in our urine. B12 has many important roles in the body which
includes playing a vital role in the normal functioning of the brain and the nervous system
and in the formation of red blood cells. Our body produces millions of red blood cells
every minute but if we don’t have enough vitamin B12, cells cannot multiply properly. So as we can see having adequate levels of
vitamin B12 is absolutely crucial for health. So what are the symptoms of not having enough
B12? Well there are a wide variety of symptoms. Some of the most common are a sore and red
tongue, mouth ulcers, pins and needles and tingling, depression, fatigue and memory problems
to name just a few. So how much vitamin B12 should we be taking
and why? Well let’s here now from Dr Joel Fuhrman….The
B12 needs for vegans are higher than the B12 needs for a meat eater. In other words these meat eaters are getting
animal products at almost every meal so they’re taking a little B12 at each meal when you’re
on a vegan diet people are taking a pill once a day and the ability of the body to absorb
B12 at one moment in the day is limited so that if you’re going to take B12 in a supplement
then the RDI of 4mcg a day is not sufficient. You need to take 100or 200mcg a day so by
diffusion we can get higher amounts in the bloodstream because we’re only taking it
at one time. Intrinsic factor can only absorb about 2mcg
of B12 and that’s not sufficient and that’s at one time. So we get the rest by diffusion and we take
a higher dose the 2% of the total dose we can get by diffusion assures us we’re getting
enough B12. So I’m suggesting that vegans take a much
higher dose of B12 than is conventionally recommend to the population at large.


  • Reply linkscollector September 8, 2017 at 7:24 am

    Don't sea vegetables like Nori or wakame have B12?

  • Reply Eelke Aptroot September 8, 2017 at 7:28 am

    Yes, don't worry any basic B12 pill contains a megadose of B12. Personally I open the caps and redose the stuff more regularly, I'm not sure taking a months worth of B12 weekly(as recommended by the vendor) will do me any good.

  • Reply veganforlife September 8, 2017 at 7:40 am

    Brilliant advice. I concerned about 14 year old vegan son's b12 intake. Will revisit his supplement and tweak.

  • Reply Aaron Orchid September 8, 2017 at 7:41 am

    so, how much?

  • Reply R D September 8, 2017 at 9:31 am

    I am taking 2000mcg a day so good or do I need to increase ?

  • Reply R D September 8, 2017 at 9:32 am

    I hear from dr neal methyl is no good due to evidence not supported

  • Reply Manuel E. Millan September 8, 2017 at 1:40 pm


  • Reply ooo789456123 September 8, 2017 at 1:41 pm

    After 6 years vegan I can only recommend to take alternating 2x methyl B12 and 2x Adenosylcobalamin aka Dibencozide per week.
    Methyl B12 alone is not enough.
    I know because I got b12 deficient from only taking methyl B12 irregularly once every 1-2 weeks.

    (if you want to avoid the cyanide in cyanocobalamin)

  • Reply Nik Louis September 8, 2017 at 1:45 pm

    Even meat eaters are B12 deficient.

  • Reply macho tony September 8, 2017 at 3:08 pm

    Why do the bottles on these b12 supplements say to take daily whether it's 500mcg or 5000mcg?

  • Reply the brink September 8, 2017 at 3:21 pm

    Almost every vegetable that can be eaten whole, fresh and raw contains all eight of the essential amino acids and, therefore, provides us with complete protein. There are twenty amino acids involved in human nutrition. Eight of these can only be supplied through our foods while the other twelve can be synthesized by the liver. A random mix of fruits will provide about the same percentage of protein per calorie as found in mother's milk. This is an adequate amount for adult humans and five times the RDA of protein per calorie consumed. This is enough for any vegan body builder as well.

    B12 is produced by bacteria that make it on plants. An animal or human can eat that same plant and get enough B12 (2.4mcg). More importantly though, B12 deficiency is only a problem if you lack a chemical called the "intrinsic factor," which causers people to be unable to absorb B12. Intrinsic factor production is reduced as dietary fat increases. This is by far the most common cause of B12 deficiency. Doctors can easily test whether a person has a normal ability to absorb B12. For those who do not, NO AMOUNT OF THE VITAMIN IN THE DIET WILL HELP. THUS, ALL OF US, VEGETARIANS AND MEAT EATERS ALIKE, ARE AT RISK OF B12 DEFICIENCY.

    A high fat diet increases this risk substantially, for two reasons. First, the colonies of B12 producing bacteria in our intestines utilize carbohydrates for fuel. As the amount of fat in our diets goes up, the amount of carbohydrate goes down, thus reducing the quantity of fuel available to the microbe. Less fuel results in a smaller colony and an overall decrease in B12 production. Second, the B12 uptake sites in our intestines become clogged when there is excess fat in the diet, further reducing B12 absorption. When reduced B12 production is coupled with impaired absorption, the likelihood of B12 deficiency becomes predictable.

    The situation is further complicated by the fact that many refined starchy foods are "enriched" with a synthetic form of vitamin B12. When doctors test for "normal" B12 levels, their results are skewed towards the high end by the fact that most people eat these foods(mostly grain products–cereals, breads, pasta, cookies, cakes, etc) on a daily basis. People who eat a grain-free diet not supplemented by this poor imitation of the natural nutrient often test "low" for B12, even if their levels are healthy and they are totally asymptomatic. This is because their B12 levels are being compared to those of people who are consuming a B12 supplement in their food at almost every meal.

    B12 deficiency can cause anemia. Symptoms of this type of anemia include: fatigue and weakness, weight loss, and sore tongue. It can also cause a neurological disorder. Symptoms of this neurological disorder include: numbness and tingling of hands and feet, memory changes, poor balance, and depression. If you don't have all of those symptoms then you don't have B12 deficiency. You have nothing to worry about. If you want to get checked for intrinsic factor levels, that is the only sure fire way to see if you're susceptible to it. As I mentioned, if you don't have enough intrinsic factor, no amount of B12 will help. Intrinsic factor is lowered by the amount of fat eaten, so watch your fat intake and you won't have to worry about B12 and many other diseases.

    After 20 years of being on a plant based diet, I still don't have any of those symptoms.

  • Reply Kamil Osięglewski September 8, 2017 at 9:22 pm

    Where to buy cyanocobalamin without magnesium stearate please? I find this one very conveniant:

  • Reply Dylan T September 10, 2017 at 5:58 am

    lookup overdose of b12 cause cancer in men.

  • Reply Saturn1030 September 14, 2017 at 9:41 pm

    Human body CAN PRODUCE and absorb vitamin B12. Check study "Vitamin B12 synthesis by human small intestinal bacteria" with following abstract: "In man, physiological amounts of vitamin B12 (cyanocobalamin) are absorbed by the intrinsic factor mediated mechanism exclusively in the ileum. Human faeces contain appreciable quantities of vitamin B12 or vitamin B12-like material presumably produced by bacteria in the colon, but this is unavailable to the non-coprophagic individual. However, the human small intestine also often harbours a considerable microflora and this is even more extensive in apparently healthy southern Indian subjects. We now show that at least two groups of organisms in the small bowel, Pseudomonas and Klebsiella sp., may synthesise significant amounts of the vitamin."

    5 years ago, when I started a Raw Vegan diet, I had very hard time. While my body was in the transition period, I had anaemia. My head was like made of stone. Could not really concentrate and think. I had tingling fingers. I felt exhausted and wanted to sleep all the time. I went to check my blood and discover that I had very low B12 = 126. I started to take different B12 pills supplements, but nothing helped me, until I tried to eat SWEET CABBAGE. I just eat it raw without processing or mixing it with anything else. Just take it and eat it. I felt so much better!!! My anaemia was gone! Since that time I had never took any vitamins supplementations, including B12. I live active live. I run 5k every day and I have long runs 20-30k each Sunday.

    Stay away from refined and processed food. Follow WHOLE food diet. Avoid oils, sucrose, salt and other preservatives and drugs. Also as a Raw Vegan I do not eat any grains, because I found it very toxic for me and I think they cause vitamin deficiency by damaging your gut. I only eat ripe juice fruits.

  • Reply mike donnarumma September 29, 2017 at 8:52 am

    im a vegan, i take 2000mcg per day , my blood is checked every 6mths, as of yet i have not had a problem, i take methylcobalamin, as it is a natural b12

  • Reply The Keto Chief October 17, 2017 at 10:54 pm

    if you have fatgue 600mcg every 6 hours not going over 2 times a day and only taking the 2nd if you start to feel fatgue or sleep

  • Reply Ivail November 22, 2017 at 11:30 pm

    I have tested my friend who WAS meat-eggs-milk eater and he was very bad B12 and D3 deficient – for 10 years the doctors have been testing him for his problems but never for B12 and D3. Finally he came to me and now a year later he is back on health and happy.

  • Reply sabeena karki January 24, 2018 at 2:17 pm

    Is 500mcg per day enough?

  • Reply Ajit Kapadia January 28, 2018 at 11:01 pm


  • Reply David Cook February 27, 2018 at 7:42 am

    Could have done with a bit more on this, but thanks anyway.

  • Reply Wayne Modz May 8, 2018 at 6:31 pm

    I was looking for a more straight forward answer…

  • Reply Stephanie Pacheco May 12, 2018 at 9:32 pm

    I'm taking 5000mg drops of B12 anyone else? I feel more energy.

  • Reply Marlene May 20, 2018 at 11:18 pm

    When your body is low in vitamin B12; it can cause you to have bad; Panic Attacks, Anxiety & depression! & much more! So get your doctor! To check your B12 Lever! Stay healthy!!

  • Reply Ram Kumar May 29, 2018 at 5:29 pm

    Excellent information in your video.

  • Reply Manny Radzky June 2, 2018 at 1:16 am

    Any diet that REQUIRES you get health from a bottle can’t be healthy long term. Eat meat!

  • Reply Phil C greyhounds June 5, 2018 at 10:16 am

  • Reply joesph gallo June 10, 2018 at 11:33 pm

    Injection of B 12 is the best way to go

  • Reply Manny Radzky June 15, 2018 at 7:36 pm

    Hey ray Rocco, no need for name calling but I guess what can I expect from a nutritionally deficient brain. If your sister is a conventional dr, she won’t know shit about nutrition. She is simply a glorified drug dealer for big pharma. Get you head of your ass, it isn’t about animal food vs plant based food it’s about how contaminated the food is.

  • Reply Chad Waldron June 20, 2018 at 8:36 pm

    Your body only absorbs what it needs, the rest you piss out.

  • Reply Flying Up July 1, 2018 at 2:04 am

    A shot of B12 in my hip will keep me from collapsing.

  • Reply Manny Radzky July 3, 2018 at 8:17 pm

    Inspiteof, are you serious, vegans don’t get sick. Many stop veganism because of health issues.

  • Reply A. S. VanHoose July 15, 2018 at 4:11 am

    Taking my B12 everyday is a meditative ritual where I engage in the egoist self-love of being a Vegan.

  • Reply Dyson Spreybar July 23, 2018 at 5:06 am

    Girl, you need a shot of B12.
    You know you do

  • Reply Emma T August 7, 2018 at 2:26 pm

    I don't understand why the animals themselves are not B12 deficient since if they're factory farmed they can only eat the grain they are given which presumably is devoid of the soil organisms that create B12 just as our food is.

  • Reply I luv to troll u September 18, 2018 at 8:51 am

    I snort b-12

  • Reply Cecily Crewe September 26, 2018 at 7:13 am

    Thank you

  • Reply Jan Doedel October 2, 2018 at 12:53 pm

    So, how much???????? 👎👎

  • Reply kinda barabara October 3, 2018 at 6:25 pm


  • Reply MMA KiNG OF THE RiNG October 4, 2018 at 12:50 am

    Can to much b12 cause hairloss

  • Reply kunaal nikk October 4, 2018 at 8:24 am

    I tested my b12 and the result is…. 106 pg/dl… 10 days before… Now i am feeling severe problems like… Concentration totally lost… Plz suggest how much dose of b12 i should take…. Plzzzz Plzzzz Plzzzz i am in big trouble…. Help me plz

  • Reply Nasser October 8, 2018 at 3:02 pm

  • Reply Tony Nesta October 30, 2018 at 12:49 am

    He Didn't say how much~~

  • Reply Ram Kumar November 17, 2018 at 8:05 pm

    Very useful video. Please advise the dose to vegetarians. Thank you.

  • Reply AvaElizabeth November 18, 2018 at 4:44 am

    none if you have MTHFR

  • Reply mrvoyagerm November 19, 2018 at 12:04 am

    So……… much Vitamin B12 should we take?

  • Reply mira jumean December 4, 2018 at 11:24 pm

    Which time of the day we should take it ?
    Please help

  • Reply Tito V December 10, 2018 at 3:04 pm

    Take 2500 mcg B12 (Methylocobalamin) once a week is all you need.

  • Reply Ross Boyd December 17, 2018 at 1:22 pm

    I have tumors in my adrenals and I have to take 10 to 15,000 mcgs a day . I started with 25to35 mcgs a day for the first year then started reducing . Before I started I couldn’t get out of bed I wasn’t getting any help from drs. . I had decided to research adrenal fatigue an it said to take massive doses of b12 so I started small an kept doubling until I reached the point I could do things again. I was exposed to a large amount of benzene years ago on the job . The tumors are growing but I don’t get any help from drs. Two of the past drs said not to touch them if I did I would die. The tumors are in my kidneys and liver also it’s been nine years since they were found. It’s very painful at times but I am on strong pain killers. So every day I wake up is a good day. Thanks to my lord and savior Jesus Christ.

  • Reply mweb1 December 28, 2018 at 6:52 pm

    Each person is different.

  • Reply mweb1 December 28, 2018 at 6:53 pm

    Applied kinesiology by a nutritionist can tell you exactly how much to take and not over the counter or from an MD. Standard Process uses B complex which is 40 times stronger than anything out there.

  • Reply mweb1 December 28, 2018 at 6:54 pm

    It's an MD, what would you expect?

  • Reply Jack Crouch January 4, 2019 at 12:28 pm

    B12b12b12b12b12b12b12b12b12b12 win the lotto

  • Reply Klariz January 8, 2019 at 7:01 pm

    Dr. Greger’s B12 Dosage Recommendations:

    •One weekly dosage of 2500 mcg cyanocobalamin B12
    •One daily dosage of 250 mcg cyanocobalamin B12
    •2000 mcg methylcobalamin B12 per day

    Jack Norris and Ginny Messina's B12 Dosage Recommendations:

    •One weekly dosage of 2000 mcg cyanocobalamin B12
    •Two weekly dosages of 1000 mcg cyanocobalamin B12
    •Two daily dosages of 2-3.5 mcg cyanocobalamin
    •One daily dosage of 25-100 mcg cyanocobalamin
    •1000-2000 mcg methylcobalamin daily

  • Reply Monica R K January 14, 2019 at 5:08 pm

    I discovered B12 deficit this year, after six months in hell due cancer suspicions, which was discarded after more exams, but I have a type of chronic atrophic gastritis that makes my stomach not absorb Iron or B12, I mentioned tinglings all over my body, the retarded physician said it is fibromyalgia, no way! Most physicians aren't prepared to think differently; I now use injections of B12 and I am not feeling okay yet, perhaps the diagnosis took too long, I was feeling mentally numb, tingling like spikes or needles all over my body skin, and the diet and the use of Manitol prior to colonoscopy almost made me collapse in the way to the hospital, my heart was barely beating.
    Gosh please medical students, physicians and professors listen to your patients, BECAUSE we know our bodies.

  • Reply Dottie Sullivan January 18, 2019 at 2:51 am

    So…. how much B12 do we need if we are and meat eater?

  • Reply Claire Vaughan February 20, 2019 at 8:37 pm


  • Reply Demenyi Robert March 12, 2019 at 2:36 pm

    do we need everyday b12?

  • Reply claudio carrizo March 19, 2019 at 9:11 am

    yo uso the thinker de

  • Reply seeamerica1 March 22, 2019 at 4:58 pm

    BEWARE – YOU CAN OVERDOSE ON B-12.!!. It happened to me…I had been taking B12 sublingual. for years + usually took 500-1000mcg After slowly increasing it to 5,000mcg I started getting numbness in my fingers + hands. There are other dangers too..headache, dizziness, diarrhea, indigestion, upset stomach, vomiting, nausea, back pain, swelling, arthritis, anxiety, nervousness and lack of coordination.

  • Reply Andrew Mosman April 2, 2019 at 4:11 pm

    Joel Fuhrman believes those that consume dead rotting flesh have more vitamin B12 in the body then those that do not @1:06. Would not those that consume large amounts of antibiotics from meat be destroying their probiotic bacteria populations? Should not meat eaters be worse off than plant eaters on this particular (b12) as well?

    Does anyone have data that suggest that putrifing high protein foods interfere with b12 absorbtion?

  • Reply chris belmore April 8, 2019 at 4:31 am

    I have all the symptoms a sore mouth but not sores all the rest b12 tomorrow for sure

  • Reply Mimmi Shaeen April 23, 2019 at 6:14 pm

    Didnt help

  • Reply Art Vale April 26, 2019 at 3:45 pm

    This video should be directed solely to vegans. I was hoping to find out what the normal B-12 RDA is–but no such luck.

  • Reply Muhammad Ahmed May 3, 2019 at 1:53 am

    For some reason this has been a hot topic recently

  • Reply Jeffrey Llewellynn May 5, 2019 at 7:43 am

    If you eat a pound of lamb's liver everyday you should be right … otherwise try a tablespoon full of flaky yeast…

  • Reply Lori Holman May 7, 2019 at 7:30 am

    Need to start my shots again,ouch❣ But could smell again,and feel a little better.

  • Reply pixeldot434 May 7, 2019 at 3:17 pm

    Does the 100-200mcg recommendation apply to all forms of B12? or was he only referring to cyanocobalamin? pls clarify.

  • Reply pixeldot434 May 7, 2019 at 3:20 pm

    Plant Based Science London,
    which brand do you personally take? How much and how often?

  • Reply Winter Summer May 10, 2019 at 4:36 pm

    very good information, thank you.

  • Reply shahilagh May 24, 2019 at 11:34 pm

    NHS gives me 1 injection every three months and they say it is enough. is it?

  • Reply stuart dagnall May 28, 2019 at 3:30 pm

    So what amount can we take.

  • Reply maremacd May 29, 2019 at 12:39 am

    What about the link between b12 supplementation and cancer?

  • Reply Edozie Nnadi May 31, 2019 at 9:50 am

    You would have use your own voice. The doctor was too fast.

  • Reply Herb Bowler June 1, 2019 at 10:18 pm

    Wrong vegans have a healthier gut flora which produces b12. Without healthy gut flora we dont absorb b12. Theirfore meat eaters are often in need of b12 more than vegans. The cow does not to take b12 no other animal ether including people as long as the gut flora is healthy

  • Reply Evan Owen July 7, 2019 at 10:22 pm

    I love Dr Fuhrman, I trust him in as much as I believe that he truly believes what he is saying. I do not trust English people in regard to journalism, news Etc. they are actually bigger bullshit artists than most Americans. I do not believe that the woman reading this information believes or necessarily understands what she is talking about. I think they grab prominent American doctor's names to promote their videos, I think this is despicable. They do the same thing with Dr Greger, who I like, but do not trust as much as Dr Fuhrman.

  • Reply perry ferguson July 8, 2019 at 1:23 am

    I what medical condition other than are inner ear infection causes one to walk drunk and loses their balance
    What causes one to lose their balance other than in a air infection

  • Reply Zuheyr Alsalihi August 3, 2019 at 4:36 am

    Great what is much. Half a kilo? 🙂

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