Lecture26: Vitamin D

Question 1

2 functions of calcium?

Answer 1

Muscle contraction, and binding of hormones to receptors

Question 2

Sources of calcium

Answer 2

Bone and reabsorption in kidney

Question 3

2 presentations of hypocalcaemia?

Answer 3

Convulsions and paralysis

Question 4

2 Presentations of chronic hypercalcaemia

Answer 4

Dehydration and kidney damage

Question 5

Sources of vitamin D?

Answer 5

Vitamin D2 and D3

Question 6

The first step to Vitamin D activation is via enzyme?

Answer 6

25-hydroxylase

Question 7

What is the enzyme at the second stage of Vitamin D activation, this time at the kidney?

Answer 7

1 alpha hydroxylase

Question 8

What is the final Vitamin D activation product?

Answer 8

Calcitriol, aka 1-25hydroxycalciferol

Question 9

The 1-alpha hydroxylase enzyme is regulated by?

Answer 9

PTH (Parathormone)

Question 10

What is the storage form of Vitamin D?

Answer 10

The liver product being , 25-hydroxycalciferol

Question 11

Factors that affect vitamin D3 entering the body?

Answer 11

Skin colour and diet

Question 12

How does Vitamin D increase the calcium absorption from the intestine?

Answer 12

Increasing the transcription of Calbindin, calcium binding protein

Question 13

Therapeutic uses of Vitamin D3?

Answer 13

Replacement therapy and immunosuppressive

Question 14

Effects of Excess Vitamin D?

Answer 14

Weakness and headaches

Question 15

Causes of Vitamin D deficiency?

Answer 15

Diet and renal failure

Question 16

What is Paget’s disease?

Answer 16

A disease of osteoclasts, cause an increase in bone resorption