WE'RE GOING TO BE COVERING WATER SOLUBLE AND FAT

SOLUBLE VITAMINS THIS WEEK.

BEFORE WE GET STARTED,

I WANT TO POINT OUT THAT A LOT OF THE INFORMATION

IN YOUR TEXTBOOK IS GOING TO COVER NUTRITIONAL DEFICIENCIES

OR VITAMIN DEFICIENCIES.

WE DON'T SEE THAT OFTEN IN THE UNITED STATES.

THEY'RE MOSTLY FOUND IN DEVELOPING COUNTRIES.

BUT EVEN IF YOU'RE NOT DEFICIENT IN A VITAMIN,

DON'T DEVELOP THE DISEASE ASSOCIATED WITH DEFICIENCY,

HAVING LOW LEVELS OF VITAMINS CAN IMPACT YOUR HEALTH.

SO LET'S GO AHEAD AND GET STARTED.

AND FIRST WE'LL JUST INTRODUCE THE

DIFFERENT CATEGORIES OF VITAMINS.

NOW REMEMBER MICRONUTRIENTS ARE BOTH VITAMINS AND MINERALS.

AND OUR VITAMINS COME IN BOTH A

WATER SOLUBLE AND FAT SOLUBLE GROUP.

WATER SOLUBLE VITAMINS ARE VITAMINS C AND B,

WHEREAS THE FAT SOLUBLE VITAMINS ARE A, D, E,

AND K. NOW WHAT I'D LIKE TO DO IS HAVE YOU TAKE A

LOOK AT THIS PICTURE AND THIS IS FROM THE BP OIL SPILL.

AND IT'S TAKEN FROM NASA,

BUT YOU CAN SEE HOW OIL IS DIFFERENT FROM THE WATER.

YOU CAN SEE THERE IS A SEPARATION OF THE TWO.

BECAUSE OIL DOES NOT DISSOLVE IN WATER

THEY'RE ALWAYS GOING TO BE SEPARATE,

AND THIS REALLY IMPACTS HOW VITAMINS ARE ABSORBED AND

THEN THEY'RE BIO AVAILABILITY OR HOW THEY FUNCTION IN THE BODY,

HOW THEY'RE TRANSPORTED, HOW THEY'RE STORED IN THE BODY.

SO THINK ABOUT THIS PICTURE OR YOU CAN THINK ABOUT

A DRESSING WHERE YOU KNOW THAT THE WATER

PART IS VERY SEPARATE FROM THE OILY PART.

THEY'RE ALWAYS GOING TO BE SEPARATE.

NOW, OF COURSE, WE LEARNED ABOUT LIPIDS THAT ACT AS EMULSIFIERS,

SUCH AS LESS AS THEM,

THAT CAN HELP BIND AND BRING THOSE INTO SOLUTION.

BUT LET'S START WITH OUR WATER SOLUBLE VITAMINS.

VITAMIN C AND ALL THE VITAMINS ARE WATER SOLUBLE.

SO THIS MEANS THAT THEY ARE GOING TO DISSOLVE IN THE WATER.

SO THAT MEANS THEY'RE EASILY ABSORBED AND TRANSPORTED.

NOW WHY IS THAT?

IT'S BECAUSE THE DIGESTIVE JUICES ARE

WATER BASED AND SO IS THE BLOODSTREAM.

SO IT'S VERY EASY FOR THEM TO BE BOTH DIGESTED AND--

EXCUSE ME, ABSORBED AND THEN TRANSPORTED THROUGHOUT THE BODY.

BUT BECAUSE THEY'RE WATER SOLUBLE THEY'RE

NOT GOING TO BE STORED IN ANY SIGNIFICANT QUANTITIES.

SO YOU'RE NOT GOING TO SEE THEM BUILD UP

AS MUCH AS THE FAT SOLUBLE VITAMINS.

AND THIS ALSO MEANS THAT THEY'RE RARELY TOXIC.

IF THEY'RE NOT DEVELOPING OR BUILDING UP

THEN THEY'RE NOT GOING TO BE STORE,

THEREFORE THEY'RE NOT GOING TO BE TOXIC.

NOW THE FAT SOLUBLE VITAMINS, THAT'S A, D, E, AND K,

THESE ARE NOT GOING TO DISSOLVE IN WATER.

THEY NEED FAT TO BE ABSORBED.

SO IF YOU'RE CONSUMING THESE VITAMINS,

BUT YOU ARE NOT CONSUMING ANY FAT WITH THEM,

THE ABSORPTION IS GOING TO BE MUCH LOWER THAN

IT WOULD BE IF YOU WERE CONSUMING THEM WITH FAT.

AND THIS COMES MOSTLY WHEN YOU

THINK ABOUT FORTIFICATION OF FOODS.

SO THEY NEED FAT TO BE ABSORBED.

THEY ALSO ARE STORED EXTENSIVELY.

NOW BECAUSE OF THAT,

BECAUSE THEY HAVE THE CAPACITY TO BE STORED,

WE DON'T NEED THEM ON A DAILY BASIS

LIKE WE DO THE WATER SOLUBLE VITAMINS.

IN FACT, YOU KNOW, VITAMIN D YOU CAN GET ENOUGH THROUGH

THE SUMMER MONTH AND WE'LL TALK ABOUT THIS IN A LITTLE BIT,

BUT THEN THAT WILL HELP CARRY YOU

THROUGH THE WINTER MONTHS IN SOME CASES.

AND THAT'S TRUE FOR A LOT OF THESE

DIFFERENT FAT SOLUBLE VITAMINS.

IT'S NOT A DAILY NEED BECAUSE THEY

ARE STORED AND CAN BE UTILIZED.

THE WATER SOLUBLE, ON THE OTHER HAND,

THEY'RE NOT BEING STORED SO YOU NEED A

MORE CONSISTENT DOSE OF THESE VITAMINS.

BUT WITH THE FAT SOLUBLE,

AND I KNOW I'M JUMPING BACK AND FORTH HERE,

BUT WITH THE FAT SOLUBLE THEY CAN REACH

TOXIC LEVELS BECAUSE THEY CAN BE STORED.

AND WE'LL GO OVER THIS.

THIS IS MOSTLY FROM FORTIFICATION AND SUPPLEMENTS,

RARELY FROM FOOD.

OKAY, I'M GOING TO MENTION THE--

START WITH THE FAT SOLUBLE VITAMINS,

AND THEN WHAT WE'RE GOING TO DO IS TALK ABOUT

VITAMIN A. SO VITAMIN A, D, E,

AND K ARE OUR FAT SOLUBLE VITAMINS,

AND WE'LL BE GOING OVER ALL OF THEM,

BUT I'M START WITH VITAMIN K IN THIS SECTION.

SO THE FUNCTIONS OF VITAMIN A INCLUDE FUNCTIONING WITH VISION,

WITH GROWTH AND MAINTENANCE.

AND THAT BASICALLY MEANS IT'S GOING TO HELP WITH

REPLACING THE BODY LININGS, SUCH AS THE SKIN.

IT ASSISTS WITH THE GROWTH OF BONES AND EVEN THE TEETH.

AND IT DOES HELP WITH IMMUNITY.

VITAMIN DEFICIENCY CAN LEAD TO PROBLEMS WITH VISION,

GROWTH AND MAINTENANCE, CONDITIONS OF THE SKIN,

SUCH AS KERATINIZATION AND IMMUNITY,

SO DECREASED IMMUNITY.

I THINK MOST PEOPLE ARE MOST FAMILIAR WITH

THE CONNECTION BETWEEN VITAMIN A AND VISION.

THIS IS AN EYE, AND THIS IS THE CORNEA OUT HERE.

WHEN YOU THINK OF A PUPIL HERE, THE CORNEA,

AND THEN THIS IS THE RETINA BACK HERE.

WHEN UV LIGHT COMES INTO THE EYE,

PASSES THROUGH THE CORNEA, AND THAT'S ONE OF THE

FUNCTIONS OF VITAMIN A. IT HELPS MAINTAIN THE CORNEA,

THE SHEATHS OF THE CORNEA.

AND IT ALSO HELPS MAINTAIN THE RETINA.

BUT SPECIFICALLY AS LIGHT COMES THROUGH AND HITS THE BACK OF THE

RETINA IT'S ACTUALLY GOING TO HIT A PIGMENT CALLED RHODOPSIN.

AND RHODOPSIN IS RESPONSIBLE FOR

SENSING THOSE LOW LIGHT SITUATIONS.

AND WHEN THE UV LIGHT COMES THROUGH IT ACTUALLY,

YOU KNOW, BREAKS APART RHODOPSIN,

AND VITAMIN A IS PART OF RHODOPSIN.

THAT FUNCTION, YOU KNOW, KIND OF THAT BREAKING APART

OF THAT MOLECULE SENDS A SIGNAL TO THE BRAIN SO

THE BRAIN PERCEIVES THE LIGHT THAT IS COMING IN TO THE EYE.

A LITTLE BIT OF VITAMIN A IS LOST, AND IT'S RETINAL.

IT'S THE ACTIVE FORM OF VITAMIN A.

AND THEN HAS TO BE REGENERATED.

SO YOU NEED THAT VITAMIN A THERE TO REGENERATE THIS RHODOPSIN,

AND IT'S ESSENTIALLY GOING TO, YOU KNOW,

SIT OUT HERE IN THE RETINA.

SO LET'S TAKE THE EXAMPLE OF WALKING AROUND AT NIGHT AND

YOUR EYES ARE SOMEWHAT ADJUSTED TO THE DARK.

AND YOU CAN SEE,

BUT SOMEONE FLIPS ON A LIGHT AND ALL OF SUDDEN

IT'S JUST THIS BRIGHT WHITE, BUT THEN EVERYTHING--

IT TAKES YOU A MINUTE AND IT--

YOU KNOW, A FEW SECONDS AND THEN YOU CAN SEE AGAIN.

YOUR EYES ADJUST BACK TO THE DARK.

WELL, THAT IS RHODOPSIN BEING BLEACHED OUT BY THE LIGHT.

THAT'S WHAT THEY CALL BLEACHING OUT.

BUT IT SENDS A SIGNAL TO THE BRAIN.

SO IT'S ALMOST OVERLOADED WITH BLINDNESS,

YOU KNOW, WHITE LIGHT,

BUT THERE'S ENOUGH VITAMIN A ACTIVE TO REGENERATE THAT

RHODOPSIN AND THEN BRING IN WHATEVER LITTLE LIGHT IS

IN THE ROOM AND ALLOW YOU TO RETURN TO YOUR VISION.

IF YOU'RE VITAMIN A DEFICIENT,

ONE OF THE FIRST SIGNS IS NIGHT BLINDNESS.

AND WHAT HAPPENS IS THERE ENDS UP BEING A LAG TIME.

SO LIGHT GOES IN AND HITS THE BACK OF THE RETINA,

IT HITS THE RHODOPSIN, YOU HAVE THE BLEACHING,

SO YOU SEE THE WHITE, BUT IF THERE'S NOT ENOUGH

VITAMIN A AVAILABLE TO THAT RETINAL,

WHICH IS WHAT WE NEED, RETINAL, A-L,

TO REGENERATE THE RHODOPSIN.

THEN IT'S GOING TO TAKE A LOT LONGER TO REGAIN VISION.

SO THAT'S ONE OF THE FIRST SIGNS.

I JUST WANT TO MAKE A QUICK MENTION OF KERATINIZATION.

KERATIN IS A PROTEIN THAT IS IN SKIN STRUCTURES,

AND THIS IS A MICROSCOPIC VIEW OF KERATIN.

BUT WHEN THE SKIN LININGS AREN'T CHANGING OVER--

I MEAN MOST OF YOUR BODY LININGS ARE CONSTANTLY

BEING REBUILT AND BROKEN DOWN ALL THE TIME,

BUT WHEN YOU DON'T HAVE THAT AVAILABLE BECAUSE VITAMIN IS

IN PART OF THAT MAINTENANCE, THAT TURNOVER,

THEN THE KERATIN TENDS TO BUILD UP,

AND YOU CAN ACTUALLY GET A REALLY, LUMPY, BUMPY,

THICK SKIN THROUGHOUT ALL OF THE SKIN,

AND THAT'S ANOTHER SIGN OF VITAMIN A DEFICIENCY.

NOW VITAMIN A TOXICITY,

YOU DON'T SEE THAT OFTEN, BUT IT ACTUALLY--

VITAMIN A IS CONSIDERED THE MOST TOXIC OF ALL THE VITAMINS.

WE USED TO LUMP A AND D TOGETHER,

BUT WE FOUND OUT VITAMIN D DEFICIENCY IS PRETTY RARE.

I MEAN, SORRY, VITAMIN D TOXICITY IS PRETTY RARE.

VITAMIN A TOXICITY CAN RESULT IN SKIN RASHES,

HAIR LOSS, HEMORRHAGE, FRACTURES,

LIVER FAILURE, AND EVEN DEATH.

AND WHAT HAPPENS WITH VITAMIN A TOXICITY,

IT'S NOT SO MUCH FROM FOOD,

AND WE'LL GO OVER THE FOOD SOURCES NEXT.

BUT IT'S A COMBINATION OF

SUPPLEMENTATION AND FORTIFICATION.

AND THAT'S GET PEOPLE TO THE UPPER LIMIT.

REMEMBER I SAY YOU DON'T REALLY NEED

TO GET VITAMIN A EVERY SINGLE DAY.

IT NEEDS TO BE AVERAGED OUT.

YOUR INTAKE MAY BE OVER A WEEKLY PERIOD OF TIME,

BUT IF YOU'RE CONSTANTLY EATING FORTIFIED FOODS WITH VITAMIN A

AND THEN YOU'RE POPPING A SUPPLEMENT ON TOP OF THAT,

THEN YOU DO HAVE A CHANCE OF HAVING A VITAMIN A TOXICITY.

SO VITAMIN A, EVEN THOUGH IT'S NOT COMMON,

IT IS POTENTIALLY THE MOST TOXIC VITAMIN.

NOW BETA-CAROTENE IS A PRECURSOR TO VITAMIN A.

SO THAT MEANS IT IS CHANGED INTO

VITAMIN ONCE IT GETS INTO THE BODY.

AND BETA-CAROTENE HAS A--

IT'S LIKE A TWOFOLD EFFECT.

BETA-CAROTENE ITSELF IS AN ANTIOXIDANT, A PHYTONUTRIENT.

WE DISCUSSED THIS EARLY ON IN THE CLASS.

AND AS THAT PIGMENT IMPLANTS WE THINK OF CARROTS,

WE THINK OF THAT ORANGE COLOR,

BUT IT'S IN THE FAMILY OF THOSE CAROTENOIDS.

ONCE IT'S IN THE BODY IT CAN BE CHANGED TO VITAMIN A. NOW ONE OF

THE KEYS WITH BETA-CAROTENE IS IT'S NOT ABSORBED AT A HIGH OF

RATE AS VITAMIN A IS AND THAT'S THE ANIMAL FORMS.

AND BETA-CAROTENE ONLY OCCURS IN PLANTS,

WHEREAS VITAMIN A SOURCES OCCUR IN ANIMALS.

SO IT'S NOT AS STRONG, I SHOULD SAY,

ALTHOUGH IT HAS A SEPARATE ACTION,

THAT PHYTONUTRIENT ACTION IS NOT GOING TO BE ABSORBED AND

HAVE THE SAME ACTIVITY AS AN ANIMAL SOURCE OF VITAMIN A.

SO THINK OF BETA-CAROTENE AS A PLANT SOURCE OF VITAMIN A,

BUT A WEAKER SOURCE.

AND THEN VITAMIN A FROM ANIMAL FOODS AS A MORE POTENT

SOURCE WOULD BE A BETTER WAY OF THINKING ABOUT IT.

SO YOU ACTUALLY WON'T FIND ACTUAL VITAMIN A IN ANIMAL--

I MEAN IN PLANT FOODS.

THIS ONLY OCCURS IN ANIMAL FOODS.

NOW BECAUSE OF THIS, YOU KNOW,

BETA-CAROTENE IS JUST ONE OF THE CAROTENOIDS,

AND SOME OF THE OTHER CARTENOIDS ARE GOING TO BE

CONVERTED INTO VITAMIN A. THEY FOUND OUT THAT THERE ARE MANY,

I SHOULD SAY, CONVERSION RATES THAT NOT ALL ARE EQUAL.

FOR EXAMPLE, IF YOU HAD ONE MICROGRAM OF RETINAL,

THAT IS EQUIVALENT TO ABOUT TWO

MICROGRAMS OF BETA-CAROTENE IN OIL.

BECAUSE BETA-CAROTENE IS FAT

SOLUBLE SO IT NEEDS FAT TO BE ABSORBED,

BUT IT COMES IN A LOT OF FOODS, SUCH AS A CARROT,

WHICH DOESN'T HAVE THAT MUCH OIL.

SO IF YOU CONSUME IT WITH A, SAY,

JUST A DIETARY BETA-CAROTENE IN CARROT,

IT'S A 1 TO 12 RATE,

SO IT'S 1/12 OF THE ACTUAL DOSE COMPARED TO A RETINAL.

AND IT'S BECAUSE IT'S NOT ABSORBED WELL,

AND IT DOESN'T HAVE AS HIGH OF BIO AVAILABILITY IN THE BODY.

NOW THERE ARE OTHER DIETARY--

WE CALL THEM PRO VITAMIN A CAROTENOIDS.

I JUST WANT YOU TO THINK OF THEM AS LESS ABSORBED, LESS ACTIVE.

YOU DON'T NEED TO KNOW THE CONVERSION RATES,

THE 1 TO 2 OR 1 TO 12.