hey everyone this lesson is on vitamin C so and this is we're going to talk about
where we can get vitamin C from our diet we're gonna also talk about the
metabolic processes we need vibin C for including catecholamine biosynthesis and
other processes as well we're also going to talk about what happens when we
actually ingest vitamin C and how we absorb it and excrete it from our body
so vitamin C is also known as ascorbic acid it is an essential water-soluble
vitamin it's required for several processes one of those is acting as a
reducing agent in collagen synthesis another one is acting as a cofactor for
enzymes in the carnitine biosynthesis pathway and another one is acting as a
cofactor for enzymes in the catecholamine synthesis pathway we're
going to talk in more detail in the next slide about these each of these
processes so we get vitamin C from our diet and vitamin C is found in citrus
fruits and various vegetables so we can remember citrus fruits with a C for
vitamin C so citrus fruits like oranges mangoes those types of fruits but we can
also get it in tomatoes and strawberries and we can also get it in from
vegetables like potatoes Brussels sprouts and broccoli so again think of
those citrus fruits and if we don't get enough vitamin C if we have a vitamin C
deficiency this causes the condition known as scurvy so what do we need
vitamin C we talked about those few processes before where vitamin C is
required vitamin C is required in collagen synthesis process of collagen
synthesis uses iron and actually oxidizes iron from ferrous to ferric so
Fe 2 plus 2 Fe 3 plus through a hydroxylation reaction and vitamin C
actually acts as a reducing agent so it reduces fe 3 plus 2 Fe 2 plus so ferric
back to ferrous ion now vitamin C is also used in catecholamines synthesis so
in the process of catecholamines synthesis when we have dopamine and
dopamine becomes acted on by the enzyme dopamine beta hydroxylase that enzyme
dopamine beta hydroxylase actually requires vitamin C so that is why we
need vitamin C in catecholamine synthesis to produce Noora
and the third process where vitamin C's required is carnitine biosynthesis
carnitine biosynthesis there's actually a couple of enzymes the first enzyme in
the pathway requires vitamin C so the conversion of tri methyl lysine to 3
hydroxy and trimethyllysine by the enzyme trimethyllysine hydroxylase
requires vitamin C and iron Fe 2 plus in the last enzyme in the pathway
converting gamma beuter o betaine to L carnitine by the enzyme gamma beuter o
betaine hydroxylase also requires vitamin c and fe 2 plus as well so the
first in the last enzymes in the carnitine biosynthesis pathway required
vitamin C 2 so if you haven't checked my catecholamine synthesis or carnitine
biosynthesis lessons please check those out as well if you want more details on
these pathways so these are where vitamin C is required for our body where
we need it collagen synthesis catecholamine
synthesis and carnitine biosynthesis so how do we absorb and metabolize vitamin
C vitamin C's again taken in our diet and it is a water-soluble vitamin so it
can be ingested but it has to be actively absorbed within the small
intestine it's not a lipid soluble vitamin so it's absorbed in the small
intestines any excess that is not absorbed in the small intestines is
actually degraded in the intestines there is a process of reversible
oxidation to what we call the hydro ascorbic acid the hydros korvac acid is
also an active form as well and if we take up too much if we absorb too much
vitamin C the vitamin C is actually essentially is excreted in our urine
when the blood levels of ascorbic acid are highs so generally the number is
roughly greater than 80 milligrams per day so again if we have greater than 80
milligrams per day of vitamin C our blood levels of ascorbic acid rise and
if it hits a sort threshold we generally excreted in the
urine so if you're essentially taking a lot of vitamin C supplements you are
going to activate that process and is simply excreted in your urine so you're
really not using it at all but again we need a certain amount so this is how we
absorb metabolized and excreted so this is the basic process of vitamin C
absorption in metabolism vitamin C is actively absorbed in the small
intestines if it's not absorbed it gets degraded in the intestines there is a
threshold of blood levels of ascorbic acid generally they say around greater
than 80 milligrams per day of ascorbic acid is gonna hit that threshold and
once you pass that threshold you're essentially going to excrete whatever's
past that threshold out in the urine so that is the general process of vitamin C
absorption metabolism and distribution within our body so now that we know
where we can get vitamin C in her diet why we need vitamin C and how we absorb
it and metabolize it we're gonna talk about what happens when we don't have
enough vitamin C in our diet so vitamin C deficiency so we're gonna talk about
that in the next lesson so if you haven't already please consider like and
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and thank you so much for watching and I hope to see you next time