Pernicious Anemia.

Vitamin B12 (Cobalamin) Deficiency Anemia:

can also cause a demyelinating disorder involving the peripheral nerves and, ultimately and most importantly, the spinal cord

Vitamin B12 is abundant in all animal foods, including eggs and dairy products, and is resistant to cooking and boiling.

Even bacterial contamination of water and nonanimal foods can provide adequate amounts.

It is stored in the liver, which normally contains reserves that are sufficient to support bodily needs for 5 to 20 years

As a result, deficiencies due to diet are rare and are virtually confined to strict vegans

Metabolism of vitamin B12:

Peptic digestion releases dietary vitamin B12, which then binds to salivary B12-binding proteins called cobalophilins, or R binders.

R-B12 complexes are transported to the duodenum and processed by pancreatic proteases; this releases B12, which attaches to intrinsic factor secreted from the parietal cells of the gastric fundic mucosa.

The intrinsic factor-B12 complex passes to the distal ileum and attaches to the epithelial intrinsic factor receptors, which leads to absorption of vitamin B12.

The absorbed B12 is bound to transport proteins called transcobalamins, which then deliver it to the liver and other cells of the body.

Pathogenesis of B12 deficiency:

Three types of antibodies have been found in pernicious anemia
parietal canalicular antibodies, which bind to the mucosal parietal cells;
blocking antibodies, which block the binding of vitamin B12 to intrinsic factor; and
binding antibodies that react with intrinsic factor-B12 complex and prevent it from binding to the ileal receptor.

An occurrence of pernicious anemia with other autoimmune diseases such as Hashimoto thyroiditis, Addison disease, and type I diabetes mellitus is well documented

gastrectomy (which leads to loss of cells producing intrinsic factor) or

resection of ileum (which prevents absorption of intrinsic factor-B12 complex), and in

disorders that involve the distal ileum (such as Crohn disease, tropical sprue, and Whipple disease

In individuals older than 70 years of age, gastric atrophy and achlorhydria can interfere with the production of acid and pepsin, which are needed to release the vitamin from its bound form in the diet.

Vitamin B12 is required for recycling of tetrahydrofolate

pallor, easy fatigability, and, in severe cases, dyspnea and even congestive heart failure. The increased destruction of erythroid progenitors may give rise to mild jaundice. Gastrointestinal symptoms

The principal neurologic lesions associated with vitamin B12 deficiency are demyelination of the posterior and lateral columns of the spinal cord, sometimes beginning in the peripheral nerves. In time, axonal degeneration

spinal cord disease begins with symmetric numbness, tingling, and burning in feet or hands, followed by unsteadiness of gait and loss of position sense, particularly in the toes

Diagnosis is made by
(1) low serum vitamin B12 levels,
(2) normal or elevated serum folate levels,
(3) serum antibodies to intrinsic factor,
(4) moderate to severe megaloblastic anemia,
(5) leukopenia with hypersegmented granulocytes, and
(6) a dramatic reticulocytic response (within 2-3 days) to parenteral administration of vitamin B12.


  1. mbbs in Philippines
    Every year, almost 8000 foreign students take admission in Philippines Medical universities and out of which around 50% are Indian students. The standard of education in Philippines universities is well known around the world. Thousands of doctors from these medical universities are sent to various countries like USA and UK every year. There are around 2299 higher educational institutions and 40 medical colleges. The main benefits of pursuing MD degree from

    Top Medical Colleges in Philippines :


    Top Searched Topics on MBBS in Philippines

    study mbbs in philippines
    philippines medical colleges list
    best medical colleges in philippines for indian students
    philippines medical colleges
    best medical colleges in philippines
    mci approved medical colleges in philippines

    for more information contact us : +91 90329 55688

  2. I found so many interesting stuff in your blog especially its discussion. From the tons of comments on your articles, I guess I am not the only one having all the enjoyment here! keep up the good work.
    vitamin b12 shots for energy

  3. UV GULLAS COLLEGE OF MEDICINE is one of Top Medical College in Philippines in Cebu city. International students have the oppertunity to study medicine in phillipines at affordable cost and world class University. The college has successful alumni who have achieved well in the fields of law, business, politics, academe, medicine, sports and other endeavors. At University of the Visayas, we prepare students for a global competition.

    Direct MBBS Admissions Open: 2020-21
    Mobile No: +91 90329 55688
    Apply Now:

  4. This is highly informatics, crisp and clear. I think that everything has been described in systematic manner so that reader could get maximum information and learn many things. coronavirus rapid test

  5. MBBS in Philippines Wisdom Overseas is authorized India's Exclusive Partner of Southwestern University PHINMA, the Philippines established its strong trust in the minds of all the Indian medical aspirants and their parents. Under the excellent leadership of the founder Director Mr. Thummala Ravikanth, Wisdom meritoriously won the hearts of thousands of future doctors and was praised as the “Top Medical Career Growth Specialists" among Overseas Medical Education Consultants in India.
    Why Southwestern University PHINMA
    5 years of total Duration
    3D simulator technological teaching
    Experienced and Expert Doctors as faculty
    More than 40% of the US returned Doctors
    SWU training Hospital within the campus
    More than 6000 bedded capacity for Internship
    Final year (4th year of MD) compulsory Internship approved by MCI (No need to do an internship in India)
    Vital service centers and commercial spaces
    Own Hostel accommodations for local and foreign students
    Safe, Secure, and lavish environment for vibrant student experience
    All sports grounds including Cricket, Volleyball, and others available for students


Popular Posts