هلا فيك ايمان خيري
خذ هذه المعلومات يمكن تفيدك وإذا فيه اي استفسار أنا جاهز
Vitamin D3 (heaife)
“Anti-ikets vitamin, anti-stemaaia vitamin”.
hemisty
7-dehydheste is the pes (pvitamin) f vitamin D3 (heaife). It is pesent in sbtanes fats.
Synthesis f vitamin D3 fm 7 dehydheste eqies expse t sn ight, athe than dietay sppy. Vitamin D3 is nsideed an atypia vitamin sine it an be synthesized inside bdy. It is a vitamin that depends n snshine “snshine vitamin”
Ses:
Pvitamins: They give vitamin D2 and D3 by taviet ays.
Egste (pvitamin D2): widey distibted in pants espeiay yeast.
7-dehydheste (endgens se f vitamin D3): in animas ny. It is fmed by intestina msa fm heste and passes t the iatin t beme sbtanes. Ths, expse t snight is essentia f fmatin f vitamin D3.
Ses f vitamin D3 itsef:
d ive i, tna ive i, egg yk, btte. Mik is a p se f vitamin D3.
Ativatin f vitamin D3 (heaife):
Fist hydxyatin eatin in the
ive by misma hydxyase
It adds H at psitin 25 t fm
25 hydxyheaife
(25-H D3, 25-H-).
Send hydxyatin eatin s in the kidney.
The ena mithndia Hydxyase enzyme adds a H t eithe psitin 1 psitin 24 depending pn the bd aim eve.
In ase f w aim eves (hypaemia), thee is a high eve f paathyid hmne. It stimates hydxyatin at psitin 1, theefe, 1,25 Dihydxy heaife (1,25 DH) is synthesized.
1,25 DH is the me ptent than 24,25 DH. 1,25 DH is as temed aiti sine it ntains thee hydxy gps at 1, 3 and 25 psitins.
Fntins f ativated vitamin D3:
The main fntin f 1,25 di H is t maintain nma pasma aim
eves. It pefms this fntin by:
Ineasing ptake f aim by the intestine. 1,25 dihydxyheaife ats a steid hmne. It entes the intestina es whee it binds t a speifi ytsi eept. aiti eept mpex then binds t a speifi DNA seqene stimating the expessin f a speifi gene that endes the synthesis f aim binding ptein temed abindin.
Minimizing ss f aim by the kidney
Stimating esptin f bne when neessay. It stimates stebasts, whih seete akaine phsphatase. Akaine phsphatase enzyme ineases depsitin f phsphate and sbseqent bne mineaizatin. 1,25 di H stimates the mbiizatin f aim and phsphs fm bne in the pesene f PTH.
Defiieny f vitamin D:
ases:
Deeased intake with imppe expse t snshine.
Deeased absptin as in ase f bsttive jandie.
Deeased ativatin as in ase f ive and kidney diseases.
Faie f binding between ativated vitamin D3 and its eept.
Manifestatins f defiieny:
I- In adts: stemaaia, haateized by bne sftening de t defetive mineaizatin. stemaaia is me mmn in wmen with mtipe pegnanies and bad eating habits.
stemaaia is manifested by:
Bne defmities.
Bne pain and ahes.
Easiy fated bnes with deayed heaing.
II- In yng gwing hiden: ikets, haateized by:
Sftening and defmities f bnes
Deayed teething, standing and waking.
Bw egs, bssing f fnta bnes, pigen hest, and ikety say de t enagement f the sthnda jntin.
Vitamin D esistant ikets:
Patients with kidney disease wi sffe fm vitamin D esistant ikets. They an nt ativate avaiabe vitamin D. They ae teated by administatin f ativated vitamin D (aiti).
Bihemia hanges in vitamin D defiieny:
Deeased sem phsphate eves.
Mid deease in sem aim eves ny in sevee ases.
Ineased eves f sem akaine phsphatase (bne isenzyme).
Txiity (Hypevitaminsis D):
Vitamin D is the mst txi f a vitamins.
It is haateized by hypeaemia. aim is depsited in bnes and sft tisses ases metastati aifiatin.
It ases pemate se f stes and fntanes in
hiden eading t miephayصغــر حجــم الرأس. aifiatin f kidney tisse
(nephainsis) may ead t ena faie.