If you're looking for a few extra steps and more in-dept: The precursers of vit D comes from foods (like oily fish; D3), plants (D2) and the sun D3. In the skin the suns UV-rays converts 7-dehydrocholesterol into cholecalciferol D3 (done non-enzymatically by heat). Cholecalciferol then moves into the liver (transported from the skin by vitamin D-binding-protein (DBP), and by cholemicrons from the diet) for the first part of its activation. Here it is converted by the enzyme (cytochrome P-450-based enzyme) into 25-hydroxy vit D3 (25-OH-D) (calcidiol) the step is called 25-hydroxylation, it then moves to the kidney for its second and last activation. Here the 25-OH-D/DBP complex is taken up at the surface by renal proximal cells by a specific mechanism involving cell surface receptors; megalin and cubulin. In the kidney 25-OH-D is converted to 1,25 dihydroxy vit D (1,25-(OH)2D) (calcitriol) by renal-1α-hydroxylase - this activation is called 1α-hydroxylation (patients with renal failure therefore cannot perform this step). The 1α-hydroxylase comprises 3 proteins: Cyt P-450, a ferredoxin and a ferredoxin reductase for activity. 1α-hydroxylase is strongly downregulated by 1,25-(OH)2D (calcitriol) and strongly upregulated by PTH as a calcium homeostatic loop.

I think its worth mentioning phosphate doesn't need Vitamin D for uptake from the diet. This is part of the reason why in chronic kidney disease, you have low serum calcium but high serum phosphate. The kidney can't make Vitamin D if its diseased, so calcium uptake is not enough, but phosphate can still get across from the intestines into the blood. Cheers Armando you rock by the way : )

@samuelbenson1

5 жыл бұрын

CKD - Decreased GFR, Kidney cannot excrete enough phosphate, phosphate increases FGF-23 which blocks 1-alpha-hydoxylase. Decrease Calcitriol, decrease intestinal absorption of ca and phosphate, yet kidney cannot excrete enough phosphate so phosphate remains high and binds free calcium. Decreased calcium stimulates increase in PTH, PTH increases bone turnover, leads to metabolic bone disease, pt over time has bone pain, fractures. PTH normally stimulates kidney to lose phosphate, but decreased GFR and kidney injury causes phosphate to not be excreted.

@zaman54321

4 жыл бұрын

I was looking for this. Thank you so much.

@pilatesyogataichifit

4 жыл бұрын

Anything apart from kidney disease that causes low serum calcium and high serum phosphate?

@kelseymcginnis5673

2 жыл бұрын

ahh thank you!

@Dandandandandy

2 жыл бұрын

@@samuelbenson1 saved my life thank you!

This video just taught me more in 11 minutes than my lecturer has in like 235 powerpoint slides :))))))) ur the best

@user-dd4vo3ik6n

3 жыл бұрын

Exactly 👌🏻

@kingbobbie5196

3 жыл бұрын

Asweer chale 😂

@kingbobbie5196

3 жыл бұрын

U dey UG?

@KeirDickson706

3 жыл бұрын

@@kingbobbie5196 ye

@kingbobbie5196

3 жыл бұрын

Oh nice... which year?

You forgot to mention that PTH reduces the reabsorption of phosphate from the proximal tubule of the kidney, which means more phosphate is excreted through the urine!

@nurkoleptik_art

9 жыл бұрын

Adnan Bashi I think he included that in one of his older videos which is the "bonehomeostasis (calcium phosphate) hormones" video :D

@bihishtasozan1903

8 жыл бұрын

exactly what i was confused about okay so i did understand the concept

@nellyhoffman6194

7 жыл бұрын

Thanks adnan

@cescrosado

7 жыл бұрын

Adnan Bashi that's the fosfaturic action of PTH, exactly!! On the other hand, calcitriol does not do that treating equally calcium and phosphate (reabsobring both of them, PTH only reabsorbed calcium) and so, if there's an excess of calcitriol (vit D), they can precipitate.

@tonyboroni6949

7 жыл бұрын

not true i have both high phosphate and pth with low low t4 wich i take meds for but nothing i can do for my pth issues so im fct, this condition was missed for years now i have perment bone and liver problems now and heart racing issues.

what would i do in med school without your videos

@lientranthi2261

7 жыл бұрын

Zeynep Ece Arslan Tra

@aleksandarjoe4290

6 жыл бұрын

There are a few factors in solving sarcoidosis pain naturally. One resource I discovered that succeeds in merging these is the Remission Crusher Tactic (check it out on google) without a doubt the best plan that I've seen. Check out the interesting info .

@windiandini6919

6 жыл бұрын

trueee

@obviouslytwo4u

5 жыл бұрын

go vegan and work it out for yourself

@cristymendez9385

3 жыл бұрын

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this is truly an amazing explanation in a short amount of time compared to long complicated lectures ! thank you so much sir

you are such a lifesaver. this was so clear. cleared a lot of confusion I had on the main hormone that controls bone growth and remodeling. keep up the great work! looking forward to more of your work.

You've got some wonderful content in here!!! I discovered this channel a few weeks ago and my whole study game has changed ever since! Thank you so much @armandohasudungan

your endocrinology videos are second to none, great job!

You have a gift of teaching! Your videos are so clear and easy to comprehend! THANK YOU!!!!!!!!

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I just love this guys handwriting. It's so regular and consistent.

@33bien

6 жыл бұрын

yes he is great writer and draws beatifully

@desifeminism4576

2 жыл бұрын

Truuuuuuuu

amazingly well explained, thank you!

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definitely very helpful for my upcoming nutritional physiology exam!

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i had an eyegasm while watching this, also your accent is so good!! tysm for this, i search everywhere for a good video about calcium homeostasis and here i am. tysm for explaining it this way. also, the drawings, i loved them!! thank you thank you

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Possible Correction: I may be wrong about this but after some researching, I found that C-FMS you mentioned on osteoclast is actually the gene that encodes CSFR-1 which is the receptor on osteoclast. If someone else could also research and confirm or deny this, that would be great! Thanks! Your videos are awesome!

THANK YOU for such an organized way Really helpful!!

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videos like this in youtube became my teachers in online class.. I shouldn't enroll in school 😂.. I should enroll in youtube😂

This video is super awesome And has proved to be so much helpful to me. Thanks for this video.

Thank You! Finally a good explanation of the calcium system. I wonder why it is often claimed that one cannot feel when bone is decreasing or osteoporosis sets in. The acid that "eats" the bone due to the osteoclast activity must be painful. Acid/nerves=pain.

OH MY GOD, I LOVE YOU DUDE, U MADE THIS CONCEPT SO EASY TO LEARN

This video is a great way to recap physiology of Ca2+. Pictures help alot. Thanks!

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thanks aloooot ... you always help me on my medical study .. thanks again

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I mean, after watching so many of your videos I must thank you for all your effort to put this out there. I know that you get revenue from this and that all video images are outsourced from an artist that works in partnership with you, but that does not take any merit from it. Huge Thank you

Thanks - again!!!! very good explanation

although my studies are in French but this explanation was very helpful.. Thank U Mr. Armando /big hi from Algeria :)/

Thank you for this video😭🙏🏻

Brilliant, that's very helpful. I appreciate you

Came here for Rank Ligand actvt and did a quick review of The 3 hormones!! Thanks a lot! ✊

just great work . thanks very much

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Really enjoyed this video

You and ninja nerd have saved my LIFE !!!!

Tanks sir...without this vedio i can't to do anything....in my endocrinlogy thanks

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Thank you sooo much for this great channel!!!

thanks, very informative. PTH also reduces phosphate reabsorption by the proximal tubule, resulting in an enhanced excretion of phosphate in urine.

Thank you soo much, that was incredibly helpful

A lot of Love from Kenya♥️🇰🇪

Buena clase, rápido y al grano

thank you for ur efforts

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this is so helpful man, thanks

Great! :) Please explain rapid and slow action of calcium homeostasis as well

thank you man ! your videos are really helpful for us med students keep up the good work 😁😁

You help me pass nursing school! Thank you

Explanation was awesome along with drawing 👍👌

good explanation...thank you armando

Nicely Drawing and Nice Class❣️

this was soooo helpful thank you so much!!

Continue ur great work sir 🙂👍ur the best

facing possible parathyroidectomy after years of hyperparathyroidism (maybe my lifetime) and this is the FIRST explanation of the why of the many attempts over the years for the various 'treatments' tried to little avail. I've doubled my D3 intake, for starters, now that I understand its role.

So helpful ❤ Thank you so much .

Thanks a bunch 🌷🌷 it helped a lot

Perfect as usual.

thank you so much sir... very helpful for me...

Great lecture!

I can understand whats actually happening thanks to you. please upload more and more vidss

Thanks ... that was very clear

This video is amazing...i mean i was about to spend 3 hrs on this metabolism now with this video in just 20 min i gain all concept regarding ca metabolism ...thanks...thanks alot

GREAT WORK !!

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Thank you so much.

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That was great!!! Thank you!

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Nice work. Keep on going.

Best Teacher

Thank you sir

Mind-blowing explanation.:))

Great video, thanks

Awesome video!Thank you!!!!!

This is amazing - thanks for helping me decipher Ca/Mg/P regulation for my second year med school course :)

@DrHistoryV

8 жыл бұрын

+David John Hume helped me in physiology first year too

Thank you..i understand it even better than reading books or in class😅...Gracias❤