Mousa’ab Abdulrhman R. RVitamin B12:Anemia

So how do we start !

36 years male presented to the clinic with3 month history of tiredness and SOB after Jogging

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Anemia Pathophysiology Classification

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Fact

Most common cause of anemia is blood loss

Basics

Function Of Vitamin B12 :Important for metabolism.Formation of red blood cells .Maintenance of the central nervous system..

Vs Folate B12

Onset

Presentation

Arrest of Methonoin FormationArrest of Erythrocyte Mutation

Within Months Within Years

Symptoms of Anemia

Never Neurological

Symptoms of Anemia

Neurological Symptoms Are Common

Etiology

Lab

Folate decrease B12 decrease

Decrease

WNL

Increase

Increase

Homocysteine

Methylmalonic Acid

Fact

Folic Acid Supplement Can Mask Vitamin B12 Deficiency

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Basics

Fact

Vitamin B12 is naturally available for human use only through ingestion of animal proteins. Unfortified plant- based foods do not contain vitamin B12.

Supplement !

Fact

The dietary reference intake for an adult ranges from 2 to 3 µg per day

Vit B12 daily Consumption

Fact

Vit B12 “cobalamin” , is a water-soluble vitamin

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Fact Decreased absorption/Interactions!

Excessive alcohol intake

Reduced vitamin B12 levels may be more common with PPIs than with H2-blockers

Folic acidAnticonvulsants Nitrous oxide NicotineNeomycinMetformin (Glucophage)

Aminosalicylic acid can reduce oral vitamin B12 absorption,

particularly in large doses

Phenytoin, phenobarbital

Hormonal contraception

Most likely Populations to Get B12 Deficiency

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Fact

Oral contraceptive users generally have lower serum vitamin B12 levels than nonusers

Ask about Drugs !

Fact

Nursing infants of mothers who adhere to a strict vegetarian or vegan diet throughout their pregnancy and while breastfeeding might also experience serious B12- related deficiency effects ,Even when the mother is not anemic or symptomatic in any way.

Ask about Diet !

During a checkup for HTN, a 65-year-old female reports a 2-month history of tiredness, feeling faint from “getting up too fast”, and “memory problems”.

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All patients newly diagnosed with unexplained cognitive decline or dementia should be assessed for a possible vitamin B12 deficiency

What may lead to depletion and deficiency?

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Pernicious anemia is an autoimmune disease in which antibodies attack gastric cells, resulting in impaired production of intrinsic factor that is critical for absorption of vitamin B12.

Fact

Fact

Pernicious anemia, is the most common cause of B12 deficiency WorldWide , but In the US, most cases of vitamin B12 deficiency are due to malabsorption.

Surgical Procedure

Ileal resection >20 Cm

Fact

Nitrous oxide causes the inactivation of vitamin B12, which might result in acute hematologic or neurologic complications of vitamin B12 deficiency. Because nitrous oxide is a commonly used anesthetic in surgery, people at risk (e.g., the elderly) should be monitored for a developing symptomatic vitamin B12 deficiency.

During Surgery !

Bariatric surgery

Fact

No single symptom, or cluster of symptoms, has been uniquely associated with inadequate levels of vitamin B12.

Fact

Today, megaloblastic anemia is most likely due to a vitamin B12 deficiency until proven otherwise

The Most Common

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BasicsWhat are the symptoms of B12 deficiency?

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Usually Legs FirstDistal & Symmetrical,Common in Alcoholic

Sensory + Motor

ChronicNeuropathy

Vit B12 is Common e.g of Metabolic Neuropathy

Who should be Tested For B12 deficiency?

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Complete blood count (CBC)Peripheral blood smearSerum cobalamin (B12)

Not all patients with a vitamin B12 deficiency will have hematologic manifestations.

a low serum B12 level does not automatically mean a deficiency.

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BasicsOrder:

have been associated with :

Multiple myeloma Oral contraceptivesFolate deficiencyPregnancy

Fact Falsely low values !

have been associated with :

Liver diseaseMyeloproliferative disordersRenal insufficiency

Fact Falsely Normal values !

Polycythemia vera Essential thrombocytosis

Myelofibrosis Chronic myelogenous leukemia (CML)

So it is important to evaluate further.

So What To do ?

Complete blood count (CBC)

Peripheral blood smear

Serum cobalamin (B12)

Are Not Specific , Nor Accurate

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Confirmatory Testing

Homocysteine (Hcy) Methylmalonic Acid (MMA)

By far, the most common, accurate, and widely used confirmatory tests for identifying vitamin B12 deficiency are tests for......

low levels of vitamin B12 increases in total serum Hcy.

is a sensitive indicator for a vitamin B12 deficiency

Shilling Test Differentiate b/w Nutritional B12 def. vs IF

Not Used Anymore !

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There is no gold standard for determining cobalamin deficiency.

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To prevent a vitamin B12 deficiency, you should advise all patients 51 years of age or older to consume synthetic vitamin B12 daily. Dosage recommendations vary.

Prevention !

Fact

High vitamin B12 level in elderly individuals may protect against brain atrophy or shrinkage associated

with Alzheimer's disease and impaired cognitive function

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Fact

Vitamin B12:has extremely low toxicity and even taking it in enormous doses appears not to be harmful to healthy individuals.

Adverse Effect !

Fact

Cobalamin replacement is effective because crystalline forms of B12 can be absorbed even when animal protein-bound forms cannot be digested.

Replacement

Fact

Vitamin B12 is used to treat :Vitamin B12 deficiency

Cyanide poisoningHereditary deficiency of transcobalamin II.

Vitamin B12 is Not carcinogenic, teratogenic, or mutagenic It is considered safe even at 1,000 times the RDA.