Name: 9.2 維生素：維生素D (9.2 Vitamins: Vitamin D)
Uploaded: 2021-01-14T05:45:48.000Z
Duration: 8 min 30 s
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- WELCOME TO THE SECOND SECTION ON VITAMINS.

未來進行式

THIS SECTION'S GOING TO BE COVERING VITAMIN D. WE'RE GOING

TO START WITH THE FUNCTIONS OR THE ROLES OF VITAMIN D.

AND THE MAIN FUNCTIONS ARE REGULATION OF BLOOD CALCIUM.

WITHIN THE BLOODSTREAM AT A VERY TIGHT LEVEL.

AND WHAT VITAMIN D IS IT HELPS REGULATE IT,

BUT MOSTLY WE THINK OF IT AS HELPING IN THE ABSORPTION

OF CALCIUM FROM THE INTESTINES INTO THE BLOODSTREAM.

ALSO HELPS US REGULATION OF PHOSPHORUS AND,

AND I JUST MENTIONED, RAISING BLOOD CALCIUM LEVELS,

IN VITAMIN D DEFICIENCY  HAPPENS IN CHILDREN.

AND YOU CAN SEE IN THIS IMAGE HERE HOW THE LEGS ARE--

THEY'RE NOT FRACTURING OR BREAKING, THEY'RE SOFTENING.

THEY'RE SO SOFT THEY CAN'T HOLD THE SUPPORT,

IN THIS CASE A CHILD THAT'S TO BE SUPPORT.

SO THIS IS A SOFTENING OF THE BONES AND IT'S CALLED RICKETS.

IN ADULTS THIS CONDITION IS CALLED OSTEOMALACIA,

ONE THING I WANT TO POINT OUT IS IN RECENT YEARS--

MEAN IT STARTED DECADES AGO BUT IN THE MORE

AND MORE MAINSTREAMED THAT VITAMIN HAS MANY,

MANY MORE ROLES THAN JUST CALCIUM REGULATION.

AN INCOMPLETE LIST OF ALL THE CONDITIONS THAT

A VITAMIN D DEFICIENCY OR INSUFFICIENCY MAYBE

AND ONE OF THE REASONS IS THAT VITAMIN D WILL BIND

TO SMALL AREAS OF DNA AND IT INITIATES THIS CASCADE

MOLECULAR INTERACTIONS, AND THIS IMPACTS GENES.

THEY'VE FOUND OUT THAT ARE MORE THAN 50 GENES

AND TISSUES THROUGHOUT THE BODY THAT ARE KNOWN TO BE

REGULATED BY THE ACTIVE FORM OF VITAMIN D. IN ADDITION,

VITAMIN D HAS A ROLE INTO WHICH THE DEGREE

A LESS SPECIFIC CELLS TO MORE SPECIFIC CELLS.

AND WHAT I MEAN IS THERE CAN BE A GENERALIZE CELL THAT COULD

HAVE ANY NUMBER OF FUNCTIONS BUT WHAT'S CALLED DIFFERENTIATION,

BUT YOU SHOULD KNOW THAT IT REALLY HELPS IN THAT SPECIFICITY

OR THAT ONE GENERAL CELL BECOMING A VERY SPECIFIC CELL.

AND THAT'S VERY IMPORTANT FOR ALL CELLS THROUGHOUT THE BODY.

BUT IT STILL CAN OCCUR, AND I'LL ACTUALLY GET INTO IT

WHEN WE START TALKING ABOUT VITAMIN K THAT HOW THESE

TWO VITAMINS INTERACT AND CAN RESULT IN SOME OF THE TOXICITY

THAT WE SEE WITH VITAMIN D. WHAT IT USUALLY RESULTS IN IF

YOU THINK ABOUT THE FUNCTION OF VITAMIN D WHICH IS TO--

REALLY ENHANCES THE ABSORPTION OF CALCIUM

FROM THE INTESTINES INTO THE BLOODSTREAM,

JUST BRINGING CALCIUM INTO THE BLOODSTREAM.

AND WE'D LOVE TO HAVE MORE CALCIUM IN THE BONES, RIGHT.

WELL, IF YOU GET TOO MUCH CALCIUM AND IT DOESN'T KNOW

WHERE TO GO IT'S GOING TO DEPOSIT IN OTHER AREAS,

HERE THIS IS A BONE, AND THIS IS A BONE HERE,

THIS IS IN THE SHOULDER, THE HUMERUS, AND THE CLAVICLE.

WHEN WE LOOK INTO THE TENDON AREAS OR WITHIN

THE LIGAMENTS YOU CAN GET THESE CALCIFICATIONS,

CALCIUM ACTUALLY DEPOSITING IN THOSE AREAS.

NOW, THIS IS JUST AN ARTERY HERE AND CALCIUM CAN DEPOSIT

IN THE ARTERIES THAT CONTRIBUTES TO SOMETHING

CALLED ARTERIOSCLEROSIS, WHICH WE'LL LEARN ABOUT.

AND THEN IN THE HEART, SO THIS IS AORTIC STENOSIS.

YOU DON'T NEED TO KNOW THAT TERM BUT IN THE HEART,

THE VALVES IN THE HEART CAN BECOME CALCIFIED,

AND THERE ARE NOT [INAUDIBLE] FUNCTION AS PROPERLY.

BUT DO KEEP IN MIND THAT IT'S NOT THAT COMMON AND

VITAMIN A TOXICITY IS ACTUALLY MORE COMMON JUST BECAUSE OF

THE FORTIFICATION AND SUPPLEMENTATION COMBINATION.

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9.2 維生素：維生素D (9.2 Vitamins: Vitamin D)

specific

cognitive

susceptible

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