b12 dosages

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mayo says Supplementation of 25-100 micrograms daily has been used to maintain vitamin B12 levels in older people. 

but the pills come in sizes great than 1000!

pharmacist says use 1000 mcg

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  • Posted

    Only a very small percentage of B12 is actually absorbed via the tablets, hence the seemingly huge dose and the best way is to incorporate foods high in vitamin B12, such as beef, liver, seafood, fish, cheese and eggs, into your diet - unless of course you have an absorption problem via your stomach or have P.A.

    I'm not a medically trained person but have had P.A. for more than 45 years.

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    • Posted

      Pernicious Anaemia (or P.A.) is a form of Vitamin B12 deficiency and in simple terms is as follows:

      In a normal healthy person the stomach lining has what are called "Gastric parietal cells" which produce "Intrinsic Factor" which travels with food through the small intestine which is made up of three parts - the Duodenum, the Jejunum and the Ileum..

      Iron is absorbed in the Duodenum, most other nutrients in the Jejunum and our friend Vitamin B12 in the Ileum.

      Here the Intrinsic Factor binds to the B12 and the "B12/IF Complex" enters the cells on the wall of the Ileum after binding to receptors on the surface of the Ileal cells, allowing it to enter the blood stream.

      Sadly some people with "traditional P,A." either do not produce Intrinsic Factor or if they do, they also produce an antibody which destroys it and it is then called "Autoimmune Pernicious Anaemia".

      In addition it can happen that we produce "Gastric Parietal cell Antibodies" and "Intrinsic Factor Antibodies" which totally wipes out any chance of absorbing the B12.

      Vitamin B12 can only be sourced naturally from food by eating animal products such as meat, fish, seafood, eggs, poultry and dairy products and if our stomach produces Intrinsic Factor then we should have no problems but there are many other causes of a B12 deficiency other than P.A. such as a vegan diet, certain medications PPIs, antacids, antidepressants etc, exposure to nitrous oxide, or other autoimmune diseases which affect absorption. The list can go on....

      If the cause of the B12 deficiency isn't dietary then it is an absorption problem so you need to find another way of replenishing B12 initially. Most absorption problems aren't treatable but a few are - notably h pylori infection - which would mean that once that has been dealt with you would be able to absorb B12 from your diet so wouldn't need maintenance shots for life as one does with Pernicious Anaemia..

      I hope this answers your question


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    • Posted

      It's called the Intrinsic Factor Antibody (IFA) test.

      Sadly the IFA test is unreliable in that it gives false negatives in people with PA half the time. In other words it is only accurate 40% to 60% of the time

      So a negative result doesn't mean that you don't have PA. However, a positive result is a sure-fire, 95% certain indicator of PA.

      It's a bit of a lottery

      Do you have any symptoms of either P.A or B12 deficiency?

      Symptoms of B12 deficiency tend to develop slowly and may not be recognised immediately. As the condition worsens, common symptoms include:

      Weakness and fatigue

      Light-headedness and dizziness

      Palpitations and rapid heartbeat

      Shortness of breath

      A sore tongue that has a red, beefy appearance

      Nausea or poor appetite

      Weight loss


      Yellowish tinge to the skin and eyes

      If low levels of B12 remain for a long time, the condition also can lead to irreversible damage to nerve cells, which can cause the following symptoms:

      Numbness and tingling in the hands and feet

      Difficulty walking

      Muscle weakness


      Memory loss




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  • Posted

    Sadly yes and getting worse!

    Thanks for your help

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    • Posted

      Please don't let it go on and on if you are having any of the above neurological symptoms..

      As a start you need to ask your doctor to test your serum B12 and serum Folate levels.

      Look at your diet - do you eat meat, fish, eggs, seafood, poultry and dairy produce?

      To go with the above you need to eat lots of leafy green vegetables, sprouts, broccoli, asparagus, spinach, peas, beans etc for Folate.

      Do you have tummy troubles?

      Anyone at any age, can become B12 deficient. However, certain people are at an elevated risk. They include the following:

      Vegetarians, vegans and people eating macrobiotic diets.

      People aged sixty and over

      People who’ve undergone any gastric and/or intestinal surgery, including bariatric surgery for weight loss purposes (Gastric bypass).

      People who regularly use proton-pump- inhibitors. H2 blockers, antacids, Metformin, and related diabetes drugs, or other medications that can interfere with B12 absorption.

      People who undergo surgeries or dental procedures involving nitrous oxide, or who use the drug recreationally.

      People with a history of eating disorders (anorexia or bulimia).

      People with a history of alcoholism.

      People with a family history of pernicious anaemia.

      People diagnosed with anaemia (including iron deficiency anaemia, sickle cell anaemia and thalassaemia).

      People with Crohn’s disease, irritable bowel syndrome, gluten enteropathy (celiac disease), or any other disease that cause malabsorption of nutrients.

      People with autoimmune disorders (especially thyroid disorders such as Hashimoto’s thyroiditis and Grave’s disease) Type 1 diabetes, vitiligo, lupus, Addison’s disease, ulcerative colitis, infertility, acquired agammaglobulinemia, or a family history of these disorders.

      Women with a history of infertility or multiple miscarriages.Do you see yourself amongst any of the above people?

      You need to get "investigated".

      It took 13 years between gastric surgery for the removal of two thirds of my stomach back in 1959 when I was 17 years old before I finally got the diagnosis of Pernicious Anaemia by which time I was a walking 30 year old "Zombie".

      My then doctor asked me if I wanted the good news or the bad news. I asked for the bad.

      She said "you're going to die and you're going to die within the next 2 years"

      I asked what the good news was.

      She said "You'e not going to die within the next 2 years if you eat raw liver three times a day - or have injections of Vitamin B12 for the rest of your life"

      As much as I like liver (with bacon & onions) I opted for the injections and I'm still "clivealive" and over 75.

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