Vitamin B12 Deficiency Symptoms (ex. Depression), Why symptoms happen, Schilling’s test, Treatment


hey everyone this lesson is on vitamin
b12 deficiency so in this lesson we’re going to talk about the signs and symptoms of vitamin
b12 deficiency we’re also going to talk about why we get those particular signs
and symptoms and we’re also going to talk about laboratory investigations to
make the diagnosis and what we can do to treat it so generally b12 is acquired
from our diet and generally it’s from animal products so if we have a vitamin
b12 deficiency either through reduced dietary intake of vitamin b12 or through
one of many different compromised absorption processes either through use
of certain medications certain disease processes or autoimmune conditions or
even having a fish tapeworm if you haven’t already please check out my lesson on
causes of vitamin b12 deficiency the vitamin b12 is so important because it’s
required for the production and health of red blood cells and also the health
of the central nervous system we’re going to talk about why that is and what
happens when we don’t have enough vitamin b12 in our bodies vitamin b12 is
required for two specific and very important
enzymes within our body and there’s one enzyme in particular I want to talk
about in this lesson that I want you to remember so generally when we ingest the
amino acid methionine methionine gets converted to methylmalonic acid
methylmalonic away gets acted on by the enzyme methylmalonyl CoA mutase and
this is the enzyme that actually requires vitamin b12 and what this
enzyme does is it converts methyl malonyl CoA to Succinyl CoA so without vitamin B12
anything before that it’s gonna be backed up and what happens is methyl
malonyl CoA increases in concentrations and when that happens it
gets converted to methylmalonic acid now methylmalonic acid is the problem here
this methylmalonic acid will eventually continue to increase in concentration
and will lead to axonal neuropathy so it starts to damage neurons and it does so
in a specific part of the central nervous system the dorsal column medial
lemniscus system the DCMLS so this is what I want you to really
take away from this because we don’t have any vitamin b12 we’re gonna have
issues with using methylmalonyl CoA mutase leading to backing up of methylmalonyl CoA
increased concentrations of methylmalonic acid which eventually leads to damage to
neurons so it leads to axonal neuropathy in the dorsal column medial lemniscus
system so this leads into the clinical presentation of b12 deficiency
you get irreversible neurological symptoms from prolonged b12 deficiency
because of the axonal neuropathy so again axonal neuropathy within the dorsal
column medial lemniscus system DC MLS you’re going to get damage to those neurons
those neurons are not going to come back they’re not going to be repaired so what
you’re going to get is you’re gonna have issues with two-point discrimination,
proprioception, vibratory sense and you’re going to have symmetric paresthesias and a
shuffling gait they feel unsteady on their feet they’re not able to walk well
because they just don’t have that proprioception
so if b12 deficiency lasts and is prolonged it can lead to irreversible
symptoms such as these there are also some possibly reversible neurologic and
psychiatric symptoms including depression, irritability, insomnia, forgetfulness all
of these things can be things where if someone comes in with some psychiatric
symptoms just out of the blue sometimes it’s a good practice to actually check
a b12 level just to see you know maybe they’re just low in b12 and some of
these symptoms could just be caused by the b12 deficiency b12 deficiency also
leads to a megaloblastic macrocytic anemia so what does that mean if you
haven’t already checked out my anemia lesson please check out that lesson for
a good overview of anemia but macrocytic anemia means that the MCV of a red blood
cell is generally greater than 100 and megaloblastic means that there’s
impaired DNA synthesis and specifically that when you look
at neutrophils or white blood cells they are hyper segmented and there’s about
five or more lobes in the neutrophils so you can see in this image here we’re
seeing more than five of these lobes so it’s hyper segmented it is megaloblastic and you’re also going to get symptoms of anemia so there’s many symptoms of anemia it could
be shortness of breath, pallor, fatigue all those types of signs and symptoms of
anemia are important to look out for as well so how do we make the diagnosis and
how do we treat b12 deficiency? The diagnosis of b12 includes looking at a
b12 level so we’re gonna see low b12 level that’s pretty easy but we can also
look at methylmalonic acid levels and again we’re going to see elevated levels of
methylmalonic acid now this may come up and I just want to quickly touch on this but
sometimes you may come across homocysteine now homocysteine can be
elevated in b12 deficiency but it’s also elevated in folate deficiency so it’s
not a good marker to look at when making the diagnosis. Methylmalonic acid is the
one you always want to check even when you’re thinking of a folate deficiency
so again methylmalonic acid is going to be elevated in b12 deficiency and actually
normal in folate deficiency and we can also use the Schillings test you’re not
gonna use the Schillings test but it’s something that’s good to know about. In the
Schillings test there’s a few steps the first one is you’re going to give an IM injection of b12 so you’re going to saturate the b12 within someone’s body
you’re going to give oral b12 and then you’re gonna check their urine and if
their urine is positive for b12 the original problem was nutritional so if
you think about it the first thing was an injection of b12 it saturates all the
b12 it in their body if we give oral b12 they’re just gonna pee it out so if it’s
if they’re absorbing it well through the oral route they’re going to just pedo
because they’re just already saturated in b12 so that’s where you’re gonna get
you’re gonna find that if you see it in the urine it wasn’t a nutritional
problem but if you don’t see it in the urine it was impaired absorption so
again if b12 already been saturated through that I am injection you give
oral b12 and you’re not seeing them pee it out well that leads you to believe
that they didn’t actually absorb that oral b12 that you just gave them so that
is the basis of the Schillings test so it’s just something to know about
generally not going to do it in treatment of b12 deficiency depends on
whether it was due to impaired absorption or nutritional deficiency if
it’s impaired absorption you’re gonna probably give it by I am injection of
b12 if it was a nutritional deficiency you may just be able to get away with
just giving them oral b12 supplements so he can kind of distinguish that from the
history and if it’s on a test maybe the Schillings test and I just want to
quickly talk about some dietary options we talked about b12 coming from animal
products but two specific foods with extremely high levels of b12 are clams
in liver and it makes sense right liver is the place where item b12 is stored
within our body so it’s gonna be it’s gonna have high levels of b12 so these
are the two main foods that have extremely high levels of vitamin b12 and
other animal products also have vitamin b12 as well but I just wanted to quickly
mention them so if you haven’t already please check out my vitamin b12 lesson
on metabolism and absorption because it gives some more detail some more
information on the process in general and if you haven’t already please
consider liking subscribing and clicking the notification Bell to help support
this channel and thank you so much for watching and I hope you see you next
time

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6 thoughts on “Vitamin B12 Deficiency Symptoms (ex. Depression), Why symptoms happen, Schilling’s test, Treatment

  1. great, but I cannot eat any animal products, as I am totally aware of how human beings treat animals. Since i have been a vegan for decades (and healthy), can it be that the Intrinsic Factor synthesis is reduced in me (in all vegans) just because we do not trigger its synthesis?
    I sometimes use patches. Sometimes. And is it possible that we produce our B12 thanks to our intestinal bacteria, like cows do?

  2. This is pretty good but it must be quite old because schillings test is no longer available and also you would want to look at homocystine because with low folate you will have low B 12 in term because they work together in unison as methylation

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