Vitamin D & Rickets

Question 1

What is the difference between cholecalciferol, calcidiol and calcitriol?

Answer 1

Cholecalciferol = Vitamin D3 (oral form)

Metabolized in liver

Calcidiol = 25-hydroxyvitamin D

Metabolized in kidneys

Calcitriol = 1,25-dihydroxyvitamin D, active form

Question 2

What are the physical skeletal findings of Rickets?

Answer 2

1) Frontal bossing
2) Delayed closure of fontanelles
3) Craniotabes
4) Rachitic rosary
5) Harrison sulcus
6) Widening of the wrist with bowing of the distal radius and ulna
7) Bowing of femur and tibia

Question 3

What are the X-ray findings of Rickets?

Answer 3

1) Widening of the epiphyseal plate
2) Loss of zone of calcification at epiphyseal/metaphyseal surface
3) Cupping, splaying and stippling of the cortical spurs at the growth plate
4) Osteopenic shafts of long bones
5) Thin cortices

Question 4

What are the extra-skeletal findings with hypocalcemic Rickets?

Answer 4

1) Hypoplasia of dental enamel
2) Decreased muscle tone
3) Hypocalcemic seizures
4) Increased risk of infection
5) Increased sweating in infants
6) Dental abscess

Question 5

What are the causes of Rickets?

Answer 5

Vitamin D deficiency (malabsorption, nutritional deficiency, CKD)

Calcium deficiency (low intake, prematurity, malabsorption)

PO deficiency (low intake, prematurity, antacids)

Renal losses (McCune-Albright syndrome, Fanconi syndrome, distal RTA)