Question
The only variety of rickets in which parathyroid hormone (PTH) levels are normal is:
| A. |
Nutritional
|
| B. |
Vitamin D resistant
|
| C. |
Vitamin D-dependent Type 1
|
| D. |
Vitamin D-dependent Type 2
|
Show Answer
|
Correct Answer � B
Explanation
|
|
Ans.B. In vitamin D-resistant rickets, renal tubule’s inability to retain phosphate results in loss of excessive phosphate through urine. Therefore, even normal or higher supplementations of vitamin D are not sufficient for bone mineralization.
In Vitamin D resistant rickets:
- Serum calcium level is normal.
- Serum phosphorous level is reduced.
- Alkaline phosphatase is increased.
- Urine phosphorus is increased.
Examples include Fanconi’s syndrome.
- Since calcium levels are not decreased, parathormone levels remain normal making this a characteristic feature of this type of rickets.
- Vitamin D-dependent Type 1 rickets is due to decreased activation of vitamin D to its active form in kidney.
- Vitamin D-dependent Type 2 rickets is due to resistance to vitamin D in peripheral tissues. This resistance to Vitamin D can be overcome with high levels of this vitamin by supplementation.
Like this:
Like Loading...
