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  • - HELLO AND WELCOME TO OUR SECTION ON VITAMINS.

  • 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.

  • BUT I DO WANT YOU TO KNOW, ESPECIALLY WHEN YOU LOOK AT

  • THE RETINAL ACTIVITY UNITS EQUIVALENTS IS BECAUSE THE

  • ANIMAL SOURCES ARE GOING TO GIVE A MORE POTENT FORM OF VITAMIN A

  • THAN THE PLANT SOURCES OR THE PRO VITAMIN A CAROTENOIDS,

  • WHICH ARE ESSENTIALLY PRECURSORS IN THE BODY

  • TO VITAMIN A BECAUSE THEY ARE ABSORBED--

  • LESS OF IT IS ABSORBED AND IT'S LESS ACTIVE IN THE BODY.

  • SO YOU'LL SEE INTERNATIONAL UNITS SOMETIMES,

  • AND THIS USED TO MAKE EVERYTHING EQUAL.

  • IT DIDN'T MATTER IF YOU WERE GETTING VITAMIN A FROM, SAY,

  • A BEEF LIVER OR YOU WERE GETTING BETA-CAROTENE FROM CARROT.