This week we are learning about the 
vitamins. 
We can classify vitamins as either fat 
soluble or water soluble. 
So, think a little bit about the 
digestive processes that we talked about 
when we, you read over the different text 
on fat soluble vitamins. 
Structurally, fat soluble vitamins look 
like other fat. 
We can see the similarities here between 
the carotene retinol and a simple fatty 
acid. 
They're absorbed into lacteals along with 
our fat. And so, if you don't eat fat, if 
you actually physically try to not eat 
any fat at all, you would not absorb your 
fat soluble vitamins. 
I'm just going to go over some key 
concepts of each of the fat and water 
soluble vitamins but do continue to read 
your texts and the links I've provided to 
the Office of Dietary Supplements for 
complete information on each of the 
vitamins and minerals. 
In the case of Vitamin A, it has a 
significant role in our visual cycle. 
It's actually a part of the compound 
Rhodopsin. 
The rod cells are very important for 
seeing in the dark. 
They're very sensitive to light and so 
you only need low levels of light to 
activate your rod. 
And so. 
When light hits these Rhodopsin 
molecules, the retinal, the vitamin A in 
the compound will actually change it's 
structure and send a signal to the brain, 
with results and sight. 
This retinal does need to be recycled and 
returned to the retinal form to continue 
to be activated. 
In vitamin A deficiency, long term, one 
can actually develop night blindness, 
where one cannot see in low level light. 
To get a little bit of an idea of how 
vitamin A works with these rise in cones 
or how vision works with the rise in 
cone, vitamin A on the rise, you can do a 
little experiment. 
So this little experiment you can do by, 
standing in a dark room that's located 
right next to a bright room, or right 
next to a sunny day outside. 
What you do is stand in this dark room 
until your eyes adjust to the light. 
Do take note of what you can see and how 
well you can see. 
Next, go outside, or into the bright 
room, for just a few moments. 
And then, go back inside. 
What you'll notice when you go back 
inside, is that everything's darker, and 
you can't see as well. 
Now, your eyes will readjust, over time, 
and you'll see again. 
Now this isn't just because of how your 
pupils are dilating. 
This is also because when you went from 
the dark environment to the bright 
environment, you activated so much of 
that Rhodopsin that you exhausted it. 
And as you went back in your had to 
quickly regenerate that compound. 
To able, to be able to respond to lower 
levels of light. 
Good, vitamin D. 
Vitamin D's key concept is that we can 
actually synthesize it. 
It still is an essential nutrient, 
because we don't make enough to provide 
our bodies complete needs and depending 
on how much time you spend outside you 
may need. 
More or less. 
Depending on where you live you may need 
more or less. 
Vitamin D is actually generated from 
cholesterol in the skin. 
The ultraviolet radiation from the sun 
activates the cholesterol and it's. 
Processed in a 2-step, sequence in the 
liver and in the kidneys to form the 
active form of Vitamin D. 
So, going outside can help maintain 
Vitamin D levels and individuals that 
spend less time outside do need to get 
more Vitamin D from their diet. 
In addition, people that live in areas of 
the world where there's less sunlight, 
and that could be farther from the 
equator or that could even be in a city 
where building block a significant amount 
of sunlight. 
These people will also need to eat more 
vitamin D. 
Vitamin E's major role is it adds the 
anti-oxidants, powerful anti-oxidants, 
both in food and body so it can actually 
work on, in protecting foods from 
becoming rancid. 
It acts by neutralizing free radicals by 
donating one of its own. 
And stopping the destructive processes of 
oxidation. 
We talked a little bit about the 
susceptibility of polyunsaturated fatty 
acids to oxidation and here we can see 
again where Vitamin E could play a role 
in protecting these fatty acids. 
So, if you do eat more omega 3 fatty 
acids, more polyunsaturated fatty acids, 
you may also want to make sure that 
you're Consuming enough vitamin E. 
A key concept for vitamin E is its role 
as an anti oxidant, Vitamin E has the 
capacity to neutralize free radicals and 
reduce oxidation by donating once of its 
own electrons By meaning it can actually 
be used in foods as a preservative. 
And it's a very healthy nutrient to take 
in if you are consuming more 
polyunsaturated fats. 
Remember, polyunsaturated fats are more 
susceptible to oxidation than saturated 
fats. 
Vitamin E when it acts as an antioxidant. 
Can actually, is actually becoming 
oxidized itself. 
And Vitamin C can couple with Vitamin E 
in restoring Vitamin E's activity. 
So as you read a little about vitamins 
and minerals. 
Think about how they all play together as 
well. 
One thing that we've not mentioned here 
is selenium. 
Selenium is also very important in this 
cycle here. 
And so we see having sufficient Vitamin 
E, Vitamin C, and selenium is important 
in producting our, in protecting our body 
from oxidation. 
Vitamins Ks primary role is in blood 
clotting. 
A key concept I want to talk about in 
this is actually the role and balance of 
vitamin K in blood clotting and the use 
of blood thinners. 
So look over the slide for just a moment. 
You can actually go ahead and read in 
your text about exactly what's happening 
in this clotting process, but overall, 
Vitamin A, K is needed for clotting to 
occur. 
When Vitamin A is utilized, it is in the 
inactivated, and needs to be refreshed. 
Normally, you eat more Vitamin K to have 
a continuous supply of this. 
molecule for the clotting process. 
Now, if you clot too much you might be 
put on coumadin or blood thinners. 
Coumadin acts by blocking the recycling 
of Vitamin K, therefore reducing 
available active Vitamin K. 
When someone is put on Coumadin, they 
need to balance their vitamin K and their 
intake of vitamin K foods with their 
medication. 
Now in some cases Physicians may actually 
recommend people avoid most Vitamin K 
rich sources. 
A dietician, however, would much rather 
see a more of a balance happening. 
Now certainly, it might be dangerous if 
this balance wasn't maintained. 
And that's likely why physicians tend to 
afford the side of caution in saying, 
individuals on blood thinners should 
avoid vitamin K rich foods. 
Blood thinners actually act very much 
like. 
Rat poison, they are pretty much the same 
thing and so when you give those types of 
rat poison to rats you kill them by 
bleeding them to death. 
By blocking this clotting pathway. 
So if you ever give a rat blood thinners 
and you don't want to kill him after all, 
just feed him some Vitamin K and 
everything will be okay. 
Okay, hi so let's briefly go through the 
water soluble vitamin, please do read for 
the details of these. 
Water soluble vitamins are soluble in 
water and they are absorbed and go 
directly into our blood. 
Thiamin, Riboflavin and Niacin work 
together in our metabolic processe, look 
for them coming back when you learn about 
metabolism. 
We might not be calling them thiamin, 
Riboflavin or Niacin We'll call them ttp, 
fad and nad. 
They're very important in carrying 
electrons and hydrogens to the electron 
transport chain allowing us to produce 
energy. 
Vitamin B6 is very important in protein 
metabolism. 
It's essential for the synthesis of 
non-essential. 
Amino acid. 
Folate and Vitamin B12 are very important 
in what's termed The One Carbon Metabolic 
Processes. 
Now this might look like a pretty complex 
figure, don't be overwhelmed by it, let's 
just focus in on Vitamin B12, which is 
right in the middle of the figure and 
Folate, which is actually Was to here as 
THF, which stands for tetra hydro floric 
is one cycle here is responsible for 
gaining equation in DNA synthesis. 
DNA Methylation goes on to be responsible 
for one hundred reactions in the body, 
DNA synthesis is crucial for maintenance 
of the human organism, but even more so 
it's very important in growth and 
development, especially in fetal growth 
and development. 
Folic acid and vitamin B12 are very 
important nutrients. 
In pregnancy, and actually in the United 
States, fortification of our grains with 
folic acid was started in order to 
produce the incidents of birth defects 
affected by folic deficiency. 
We can look a little closer at vitamin 
B12's role in this process. 
Vitamin B12 is needed for the conversion 
of Homocysteine to Methionine. 
Vitamin B12 acts as a carrier for 
tetrahydrofolate to convert. 
To transfer a a metyhyl group from 
itself, Homocysteine generating 
Methionine. 
In both folate and B12 deficiency, we 
will see elevation from Homocysteine. 
Now, if you eat enough folic acid, or 
enough folate but not enough B12, 
Homocysteine will still go up. 
But the left side of this whole 
psychopair won't be affected. 
So with plenty of folate you'll still 
have DNA synthesis. 
But the recycling of that folate in the 
cetner of this diagram will stop. 
Will stop and trap the methyl group from 
5 methyl Tetrahydrofolate, - 5-CH3-THF to 
keep it back and will that methyl group 
trapped there and will impact DNA 
methylation. 
Now, if you eats lots of B12 and not 
folate, you won't provide that methyl 
group and you'll impair both systems. 
The key concept in the case of Vitamin C 
is Vitamin C's role in collagen 
formation. 
Collagen is part of various tissues in 
the body. 
When we look, we talked a little bit 
about oral health in our carbohydrates 
lecture, well Vitamin C is also important 
in maintaining oral mucosa as well as 
connective tissues. 
When we don't form proper collagen in 
vitamin C efficiency. 
You can actually see results such as 
bleeding of the gums, increased bleeding 
of the gums and this is because that 
connective tissue is not strong enough to 
keep fluids from coming out. 
You can learn more about Vitamin C and 
all of the vitamins I've talked about 
thus far, in your text, as well as one 
linking to fax sheets from the Office of 
Dietary Supplements. 
The Office of Dietary Supplements has 
information for both the health 
professional and for the consumer. 
If you look here, you'll notice I have 
actually referenced you to the health 
professional links, that is just going to 
have more extensive information than the 
ones for the consumers.