Excessive Vitamin D.....Defic Vitamin D ....what happens to

[Neuro4u]

With excessive vitamin D what happens to the bone?

With deficiency of Vitamin D what happens to the bone?

[Anonymous]

In excessive VitD ---- hypercalcemia --- metastatic calcification --- growth retardation in children because of hypercalcification while nephrocalcinosis and renal calculi in adults, may reversible in early stages but can progress to renal failure.

In deficiency of VitD ---reactively increased PTH --- osteolysis --- deficiency of calcification of osteoid matrix --- Rickets in children and osteomalacia in adult

So both will cause decreased height in chiledren, the former is by too ealy calcification of epiphyseal plates and the latter by inadequate calcification and bone deformities.

Correct me if wrong

[Neuro4u]

Excessive Vit D produces excess bone resorption, leading to osteoporosis.

Defic of vit D problem bone salts cannot be laid down into the matrix. Prob of rickets and osteomalacia.

Point to be made was either a defic of excess vitamin D produces inadequate bone mineralization.

I agree with the things you wrote above and thank you for attemping question, many people look but special people participate. :roll:

[Anonymous]

Your statement needs furthrer clarification. What is source of your information that "Exess of Vit D causes Osteoporosis?"
thanks

[Neuro4u]

First of all define resorption, then after you understand the meaning of the word, go look it up in Goljans.

Did you look it up in any other books or do you expect me to do the for you also. I have my references and you should also try.

[Anonymous]

hi neuro4u!,
you r both correct and wrong.it is true that excess vit d causes osteoporosis but it is also true that new bone formation occurs in the bones in hypervitaminosis D AS SOME other member pointed out!in chronic hypervitaminosis D,initially there is a phase of active bone reabsorption causin osteoporosis followed by osteosclerosis which is why skeletal Xrays r used in the diagnosis of hypervitaminosisD

here is a reference!from pubmed
hope this solves thios issue!!!!!!

Because the pathogenesis of osteosclerosis in hypervitaminosis D is still not well elucidated, the authors experimentally studied hypervitaminosis D3 in 66 rabbits by injecting different doses of vitamin D3. Contact radiographs of bone specimens showed various signs of osteosclerosis, including dense epiphyses and metaphyses, thickened bony articular surfaces, dense metaphyseal bands, modeling defects at the metaphysis, and dense and thickened cortical bone. The corresponding pathologic sections showed that conspicuous metastatic calcification coated the trabeculae and filled bone marrow cavity and caverns in the original but porotic cortical and periosteal new bone. Rather than being resorbed, the metastatic calcifications were embedded in a thick layer of newly formed bone 6 to 14 weeks after vitamin D3 withdrawal. This study suggests that in hypervitaminosis D3, the osteoblasts and bone marrow undergo degeneration, leading to necrosis and calcification.
.


the journals have a lot of articles about this since hypervitaminosis D esp the chronic ones is the new epidemic becos of its rampant OTC use in so many countries!!!!!!!.,
see this for example!

The supplemental requirements vary not only with age, pregnancy and lactation, but also with the quality of the diet. It is clear therefore that any recommendation for vitamin D supplementation must be made only after careful scrutiny of the diet. The indiscriminate use of over-the-counter vitamin D preparations for irritional purposes can be dangerous. People must be made aware of the potential hazards of overdosage.

The writer is a pharmacist at the National Poison Centre, Universiti Sains Malaysia, Penang.


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if yoiu disagree,plz lemme know
krishna1033

[fcwilliams]

CATFIGHT!!

[mjl1717]

For the boards at least remember that metastatic calcifications can be caused by vit D intoxication

[Anonymous]

CATFIGHT!!

Let's make this statement relvent to our USMLE dicussion :wink: .

Name the bug associated with each of the following buzzwords:

1. Cat scratch
2. Cat Litter
3. Cat bite

[mjl1717]

2of3
Cat Scratch Ds-B. henselae
Cat Litter--------T. gondi(Cat is definitive host oocysts in feces)

[Anonymous]

2of3
Cat Scratch Ds-B. henselae
Cat Litter--------T. gondi(Cat is definitive host oocysts in feces)

Cat bite ---- Pasteurella treat with amoxicillin


Cat meat --- SARS

[Anonymous]

2of3
Cat Scratch Ds-B. henselae
Cat Litter--------T. gondi(Cat is definitive host oocysts in feces)

Cat bite ---- Pasteurella treat with amoxicillin


Cat meat --- SARS

both right! very good!! :D
1. Cat Scratch = Bartonella henselae
2. Cat Litter = Toxoplasma (preg. women should not handle cat litter because toxo is part of TORCH which means it crosses placenta)
3. Cat bite = Pasterella

Hopefully we wont be tested on SARS :? .

[krishna1033]

understand the difference between a catfight and an intellectual discussion!.
sometimes hard to tell though!
bye :arrow:

:lol: