WEBVTT

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A, C, E, D, B, K.

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No, this isn't some random,
out of order alphabet.

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These are vitamins,
and just like letters build words,

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they're the building blocks
that keep the body running.

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Vitamins are organic compounds we need
to ingest in small amounts

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to keep functioning.

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They're the body's builders, defenders
and maintenance workers,

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helping it to build muscle and bone,
make use of nutrients,

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capture and use energy
and heal wounds.

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If you need convincing about
vitamin value,

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just consider the plight of 
olden day sailors,

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who had no access to vitamin-rich
fresh produce.

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They got scurvy.

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But vitamin C,
abundant in fruits and vegetables,

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was the simple antidote to this disease.

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While bacteria, fungi and plants
produce their own vitamins,

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our bodies can't, so we have to get
them from other sources.

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So how does the body get
vitamins from out there into here?

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That's dependent on the form
these compounds take.

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Vitamins come in two types:

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lipid-soluble and 
water-soluble,

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and the difference between them 
determines how the body

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transports and stores vitamins, 
and gets rid of the excess.

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The water-solubles are vitamin C


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and B Complex vitamins that are made up of
eight different types

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that each do something unique.

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These are dissolved in the watery parts
of fruits, vegetables and grains,

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meaning their passage through the body
is relatively straightforward.

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Once inside the system,
these foods are digested

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and the vitamins within them are
taken up directly by the bloodstream.

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Because blood plasma is water-based,

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water-soluble vitamins C and B have their
transport cut out for them

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and can move around freely 
within the body.

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For lipid-soluble vitamins,
dissolved in fat

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and found in foods like diary,
butter and oils,

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this trip into the blood is a little
more adventurous.

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These vitamins make it through
the stomach and the intestine,

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where an acidic substance
called bile flows in from the liver,

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breaking up the fat and preparing it for
absorption through the intestinal wall.

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Because fat-soluble vitamins can't make
use of the blood's watery nature,

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they need something else 
to move them around,

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and that comes from proteins that attach
to the vitamins and act like couriers,

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transporting fat-solubles into the blood
and around the body.

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So, this difference between water-
or fat-soluble vitamins

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determines how they get into the blood,

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but also how they're stored 
or rejected from the body.

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The system's ability to circulate
water-soluble vitamins

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in the bloodstream so easily

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means that most of them can be passed
out equally easily via the kidneys.

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Because of that, 
most water-soluble vitamins

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need to be replenished on a daily basis
through the food we eat.

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But fat-soluble vitamins have
staying power

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because they can be packed into the liver
and in fat cells.

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The body treats these parts like a pantry,

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storing the vitamins there and rationing
them out when needed,

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meaning we shouldn't overload
on this type of vitamin

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because the body is generally 
well stocked.

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Once we figured the logistics
of transport and storage,

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the vitamins are left to do the work
they came here to do in the first place.

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Some, like many of the B Complex vitamins,
make up coenzymes,

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whose job it is to help enzymes 
release the energy from food.

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Other B vitamins then help the body
to use that energy.

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From vitamin C, you get the ability to
fight infection and make collagen,

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a kind of tissue that forms 
bones and teeth and heals wounds.

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Vitamin A helps make white blood cells,
key in the body's defense,

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helps shape bones and improves vision 
by keeping the cells of the eye in check.

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Vitamin D gathers calcium and phosphorus 
so we can make bones,

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and vitamin E works as an antioxidant,

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getting rid of elements in the body
that can damage cells.

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Finally, from Vitamin K, we score
the ability to clot blood,

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since it helps make the proteins
that do this job.

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Without this vitamin variety,

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humans face deficiencies that 
cause a range of problems,

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like fatigue, nerve damage, 
heart disorders,

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or diseases like rickets and scurvy.

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On the other hand, too much of any
vitamin can cause toxicity in the body,

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so there goes the myth that loading
yourself with supplements is a great idea.

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In reality, it's all about getting the
balance right,

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and hitting that vitamin jackpot.