I YEAR MBBS CLASS PG QUESTIONS

1. VITAMIN D
RICKETS

3. Produced in skin
exposed to sunlight,
specifically
ultraviolet B
radiation. Production is greatest
in the stratum basale
and stratum spinosum
.

4. SOURCE

5. Chemical structure
5
MOST IMPORTANT FORM
It is considered as
prohormone.
BECAUSE
From which
1,25-dehydrocholesterol
synthesized. (active form)

6. 200 – 400 IU /day
[5 – 10µg/day]
1microgram of vitamin D = 40 International Units

7. Forms
D3
D2
Site
Upper small
intestine
Mechanism
Along with
lipids
Requires
bile salts
ABSORPTION

8. Action of
calcitriol on
the intestine
Action of
calcitriol on
the bone
Action of
calcitriol on
the kidney

9. Action of calcitriol on the
intestine
•Increases the intestinal absorption
of calcium and phosphate
•By increased synthesis of calcium
binding protein

10. Action of calcitriol on the bone
• Mineralization of bone at low doses
• Mobilization of calcium from bone at high doses

11. Action of calcitriol on the
kidney
•Increased reabsorption of
calcium and phosphorus
•Decreased excretion of calcium
and phosphorus

13. CLINICAL FEATURES
Children
Adults
Children
Rickets
Adults
Osteomalacia

14. Vitamin D resistant rickets (hypophosphatemic rickets)
Vitamin D dependent rickets (type I) D defeciency
Vitamin D dependent rickets (type II) D resistance
Rickets classification

15. X LINKED DOMINANT
RENAL DEFECT
INCREASED EXCRETION
DECREASED REABSORPTION

16. CLINICAL FEATURES OF RICKET
GENERAL
Listlessness
Protruding Abdomen,UMBILICAL HERNIA
hypotonia of abdominal wall muscles
Muscle Weakness(specially proximal)
Fractures

17. Pot belly

18. HEAD
CRANIOTABES softening of cranial bones

19. craniosynostosis

20. Frontal Bossing

21. • Delayed Fontanelle Closure

22. CHEST
• RACHITIC ROSARY
Widening of costochondral junction
Non tender

23. • Harrison Groove
• pulling of softened ribs by the diaphragm during
inspiration.Muscle traction on the softened rib cage

24. • Pectus carinatum

25. • Respiratory Infections
• Atelectasis
impairment of air movement

26. EXTREMITIES
• Enlargement of wrists and ankles
Growth plate widening

27. • Valgus or varus deformities

28. •WINDSWEPT DEFORMITY
combination of varus deformity of 1 leg with
valgus deformity of other leg

29. VITAMIN D DEFICIENCY
ETIOLOGY
• Most commonly occur in infancy due to
poor intake and inadequate cutaneous
synthesis
• Formula fed infants- receive adequate vit
D even without cutaneous synthesis
• Breast fed infants rely on cutaneous
synthesis or vitamin d supplements

30. Cutaneous synthesis is limited
due to
Ineffectiveness of winter sun
Avoidance of sunlight
Decreased cutaneous
synthesis due to increased
skin pigmentation

31. LABORATORY FINDINGS
• Hypocalcemia – variable finding due to action of
↑PTH
• Hypophosphatemia- due to PTH induced renal
loss of phosphate and decreased intestinal
absorption
• 1,25D level-N,↑,↓- secondary to up regulation
of renal 1 α hydroxylase due to
hypophosphatemia and hyperparathyroidism
• Some patients have Metabolic acidosis
secondary to PTH induced renal bicarbonate
wasting
• Generalized aminoaciduria

32. MANAGEMENT OF VITAMIN D
DEFICIENCY
• Should receive Vitamin D and adequate
nutritional intake of calcium and phosphorus
• STROSS THERAPY- 3-6 Lakh IU of Vitamin D
oral/IM as 2-4 doses over 1 day
0R
Daily High dose Vitamin D 2000-5000 IU/day
over 4-6 weeks
or
Daily Vitamin D intake of 400 IU/day

33. Hypervitaminosis D
It may occur due to chronic ingestion of
large doses or due to increased
sensitivity of tissues to vitamin D.
Hypercalcaemia,weakness,fatigue,vomiti
ng,diarrhoea,renal stones,hypertension.
Even coma may occur.

34. Questions

35. Seen in rickets A/E
Cupping of metaphysis
Defective mineralization
Epiphyseal dysgenesis
Defective osteoid (protein matrix)
(unmineralized bone)
formation

37. Deficient mineralization in epiphyseal growth
cartilage is seen in
Rickets
Osteomalacia
Scurvy
hyperparathyroidism

38. True about serology of rickets is
Alk po4 serum p04
↓ ↑
↑ ↑
↑ ↓
↓ ↓

39. In rickets seen
Increased ALP
Decreased ALP
Decreased phosphate in blood
Increased phosphate in blood
hyperphosphaturia

40. A 2yr old boy has vitamin D resistant rickets his investigation revealed
serum ca+9mg/dl, PO42.4mg%, ALP 1041iu/L ,normal PTH .Bicarbona
22meq/l (22-28)
which of the following is most probable diagnosis
Distal renal tubular acidosis
Hypophosphatemic rickets
Vitamin D dependent rickets
hypoparathyroidism

41. Low phosphate
Elevated alkaline phosphate

42. A 2yr old boy has vitamin d refracrory rickets
investigations shows serum calcium 9mg/dl
phosphate 2.4mg/dl (3-4.5mg/dl)ALP 1040 IU/L
(30-120iu/l).PTH & bicarbonate levels are normal
.most probable diagnosis is
distal renal tubular acidosis
Hypophosphatemic rickets
Vit D dependent rickets
Proximal renal tubular acidosis

43. True about nutritional rickets
Craniotabes
Widening of wrists
Growth retardation
Decreased phosphate in serum
Multiple fractures

45. Rickets in infants present as all
except
Craniotabes
Widened fontanelle
Rachitic rosary
Bow legs

46. All of the following are seen in rickets except
Bow legs
Gun stock deformity
Pot belly
craniotabes

48. Most common cause of genu valgum is
Osteoarthritis
Rickets
Pagets disease
Rheumatoid arthritis

49. Wind swept deformity is seen in
Scurvy
Rickets
Achondroplasia
osteoporosis

50. True about vit d deficiency rickets
Vit d3 given at a dose of 50-100mg/day
X ray knee joint is diagnostic
Rickety rosary is tender
Increased chances of respiratory tract infections
hyponatremia

51. 6lac IU /15000ug / 15mg-------------every 2weekly
Healing started
400IU10ug every day
4-6 weeks 50-150mg/dl
2000-5000 IU / 50-126ug / 0.5-2mg /day

52. hypophosphatemic rickets is characterised by
Increased forehead sweating
Charecteristically Decreased calcium
Anterior fontanelle widened
Increased ALP

53. Earlier manifestation of rickets is
Craniotabes
Rachitic rosary
Harrison groove
Pigeon chest

54. Craniotabes is seen in following except
Rickets
Syphilis
Osteogenesis imperfects
thalassemia

55. Splaying and cupping of metaphysis is seen in
Rickets
Scurvy
Pagets disease
Lead poisoning

56. Rickety rosary is seen in all except
Rickets
Scurvy
Chondrodystrophy
syphilis

57. Costochondral junction swelling are seen in
Scurvy
Rickets
Chondrodystrophy
All of the above

58. Metabolic bone disease is caused by which
vitamin excess
A
B
C
D

59. THANK YOU