Calcium homeostasis is regulated by parathyroid hormone (PTH) and vitamin D. Vitamin D deficiency can lead to rickets in children, causing softening and weakening of bones. Symptoms of rickets include bowed legs, skull deformities, enlarged wrists, and delayed dental eruption. Diagnosis is made based on lab findings of low calcium and phosphate with elevated alkaline phosphatase and PTH. Treatment involves high dose vitamin D and calcium supplementation. Genetic causes of rickets include vitamin D resistant rickets, hypophosphatemic rickets, and X-linked hypophosphatemia. Surgical correction may be needed for severe bone deformities after medical treatment.

1. Good Afternoon


2. By ; Pawan Kumar B
Moderator : Dr. Chetan B Shetty

3. Calcium – 99% of the body’s calcium is derived from
the bone
Plasma calcium -less than 1% of the body calcium.
Also takes part in the muscle and nerve function,
clotting mechanisms.

4. Absorbed in DUODENUM and JEJUNUM
The reabsorption (98%) is done by kidneys – 60% in the
proximal tubule
The primary homeostatic regulators of serum calcium
are PTH and 1,25- di OH cholecalciferol

6. • Origin – chief cells of parathyroid glands
• Factors stimulating production- decreased
serum calcium
• Factors inhibiting production- elevated serum
calcium
elevated 1,25-di(OH)D

7. Origin –parafollicular cells of the thyroid glands
Factors stimulating-elevated serum calcium
Factors inhibitin-decreased serum calcium
Action on bone- inhibits the oesteoclastic resorption
Net effect – transient decrease in serum calcium

9. Vitamin D deficiency
Reduced Ca absorption
Depressed extracellular Ca
Defective mineralization of
the bone in formation
Secondary
hyperparathyroidism
Depressed
extracellular P
Increased bone
resorption
demineralization of the

10. •
An Osteomalacic syndrome
Failure of mineralization of growing skeleton
Lack of ionized calcium and/or phosphate
Less mineralized bone per unit volume.
Seen prominently at growth plates, results in softening of
bones.

11. Nutritional rickets
Vitamin D
Dependent
rickets(VDDR)
Vitamin D resistant
rickets
Secondary rickets –
renal , GI, medications,
malabsorption
syndromes, tumor-
associated

12. VITAMIN D
deficiency
rickets
• Rare in developed countries
• Prolonged breast-feeding, vegetarian diet,
TPN, anticonvulsant drugs
• Poor dietary intake, insufficient exposure to
sunlight, malabsorption.
• Generalized muscular weakness, lethargy,
and irritability, developmental delay
• Short stature .

13. • Craniotabes • Bossing of skull
(evident after 6
months)

14. •Prominently visible
and palpable
costochondral
junction
•Sternum becomes
more prominent ,
leading to pigeon
chest or pectus
carinatum appearance

15. semicoronal
impression over
the abdomen at the
level of the
diaphragm
Caused by the
indentation of the
lower ribs at the
point of attachment
of the diaphragm

17. • A prominent promontary found
• The AP diameter of the pelvis may
decrease due to scoliosis
• If this persists in girls, it can cause
complications later in life during
childbirth

18. Bow
legs
(genu
varum)
Seen in
toddlers

19. due to displacement of
the growth plates
during the active
disease
Seen in older
children

21. • Thickening & broadening
at the level of the ankle ,
wrist.
• Muscle weakness
• Tendency for fractures
• Dental problems

22. • Delayed appearance of epiphysis.
• Physeal widening concentrated in the
middle part of the physis in severe
rickets with less involvement at the
periphery
• This translates radiographically into
cupping of the metaphyseal regions

23. Enlargement of costochondral junction
(rachitic rosary)

24. Vitamin D is
administered
orally(2m)
As a single dose-
6,00,000IU or
Over ten days
(60,000IU/day)
Maintanance dose
400-800IU/day with
calcium supplements
(30-75mg/kg/day)

26. low to
normal
serum and
urinary
calcium
low serum
phosphate
Raised alk
phosphate
& PTH
normal to
raised vit D
LAB FINDINGS
Clinical features similar to those for vit D
deficiency
Treatment : Oral administration of calcium-700mg daily

27. Normal-PTH ,serum and urinary
calcium
Raised alkaline phosphate
markedly raised vit D3
reduced serum phosphate
Changes of secondary hypoparathyroidism is not
seen.

28. • Inhibits the conversion of vitamin D to its active form
by inhibiting 1-alpha –hydroxylase
• Inheritance pattern-autosomal recessive
• The gene responsible is on chromosome 12q14

29. Low serum calcium and
phosphorus
High alk phosphate and PTH
Very low 1,25-di(OH)D
Low urinary calcium

30. Calcitriol(1-2mcg/daily)
Calcium with or without
phosphate supplements
Calcium rise and radiological
healing occurs in 6-8 weeks

31. • Defect in intercellular receptor for
1,25-di(OH)vitamin D
• Lab features –low serum calcium and
phosphorus
high alk
phosphate and PTH
markedly high
1,25-di(OH)D

32. X-linked dominant
Renal tubule’s inability to retain phosphate
Mutation in the PHEX genes sequences.
Becomes apparent at a slightly older age than
nutritional rickets (1-2 years of age)
Mother may have bowing of legs.

33. • No changes of secondary
hyperparathyroidism(tetany and musle
weakness is absent)
• Classic triad – lower limb deformities
hypophosphatemia
stunted growth –
very rare

34. Normal –serum
calcium,PTH,
1,25_di(OH)D
High alkaline
phosphate
VERY LOW
SERUM
PHOSPHATE
Urinary
calcium-normal

36. • Conservative treatment include orthopaedic shoes and
splints .
• Corrective osteotomies, depending on nature of
deformities.
• After 6 months of medical treatment.
• Discontinuation of Vit D before surgery .
• Surgical correction of angular deformities