1. Resource Person:-Prof.Dr.A.K.Dutta
Presented by:- Prateek Singh

2. Vitamin D is a
group of fat-soluble
prohormones.
Two
major forms of
which are vitamin D 2
(or ergocalciferol)
and vitamin D 3 (or
cholecalciferol).
 Production is greatest in the
stratum basale and stratum Produced in skin
spinosum . exposed to sunlight,
specifically

3. Functions of Vitamin D
Regulates the calcium and phosphorus levels
in the blood by promoting their absorption
from food in the intestines.
Promotes bone formation and
mineralization .
Inhibits parathyroid hormone secretion
from the parathyroid gland.
Affects the immune system by promoting
immunosuppression, phagocytosis, and
anti-tumor activity

4. Dietary sources of
vitamin-D
Fortified foods especially
dairy products, cereals and
vit. Supplements.
Fish, liver, oils, egg yolk &
butter.
Infants: obtain vit D
supplement from mothers
milk, infant formulas, cow
milk .

5. Why Vitamin D deficiency
occurs?
Due to:-
Inadequate sunlight exposure.
Poor access to micronutrients rich
food.
Disorder that limit its absorption.
Deficient soil quality.
Impaired conversion into active
metabolites.
Possible role of dietary fibers.

6. These lead to:-
 Learning disability
 Impaired work capacity.
 Increased susceptibility to infection

7. Deficiency causes:-
 In children :-
RICKETS:- Bone softening diz., deformity
of long bones occur.
 In adults :-
OSTEOMALACIA :- Bone thinning
disorder,proximal
muscle weakness & bone fragility.
OSTEOPOROSIS:-Decrease bone
minerilzation & inc. Bone fragility.

8. RICKETS:-
 Rickets is characterized by
bone deformities
due to incomplete
mineralization, resulting
in soft & pliable bones and
delay in teeth
formation.
 The weight bearing bones
are bent to form bow
legs

9. Risk factors
 Breast-fed infants whose mothers are
not exposed to sunlight .
 Breast-fed infants who are not exposed to
sunlight .
 Lactose intolerant.
 Individuals with red hair have a decreased
risk for rickets due to their greater
production of vitamin D in sunlight.

10. Pathogenesis of Rickets
 Appears to develop in 3 stages:-
 1 st stage Absence of adequate stores
In supply of 1,25 dihydroxy vit D
Intestinal absorption of Ca & P
Release of parathyroid hormone
1,25 (OH)2 vit D3
25(OH) vit D (in kidney)
Absorption of Ca & P Mobilization of Ca & P
from bone

11.  2 nd stage:-
Relative Hyperparathyroidism
Phosphaturia
Negative phosphorus balance
Hypophosphatemia

12.  3 rd stage:-
Relative hyperparathyroidism
Depleted 25(OH) vit D
Impaired production of
Adequate quantity of 1,25(OH)2 vit D3
Intestinal absorption of Ca & P

13. Signs and Symptoms
 Bone pain or tenderness.
 muscle weakness ( rickety
myopathy or "floppy baby
syndrome")
syndrome
 Increased tendency for
fractures (easily broken
bones), especially
greenstick fractures
 Hypocalcemia
 Tetany
 Craniotabes (soft skull)
 Skeletal deformity:Cranial,
spinal, and pelvic

14.  Bowed legs (genu varum)  Costochondral swelling
( "rickety rosary" or "rachitic
rosary")
 Knock-knees (genu valgum) or
"windswept knees.  Harison’s sulcus and pot belly

15. Diagnosis:

16. Treatment:-
 Natural & artificial light are effective
therapeutically but oral administration
preferred.
 Administration of 15,000ugm or 6,00,000
IU of vit.D 3 orally or I.M. induces rapid
healing.
 If healing lines of rickets is not seen on x-
ray plate of bone within 3-4 weeks of
therapy, the above dose may be repeated .
 Cases who respond to this therapy are further
put on 400 units or 10ugm of vitamin D 3 per

17. Requirement
 Body needs are met entirely by
conversion of 7 dehydrocholesterol to
vit D 3 in skin
Or
 in absence of exposure to UV light,
it can be met entirely by ingestion
of Vit D
 The recommended dietary intake for
vit D by infants has been accepted
as 200IU/day
and children 400IU/day

18. Hypervitaminosis – D
 Signs & symptoms - similar to idiopathic
hypercalcemia.
 Symptoms include:-
Hypotonia, anorexia, irritability,
constipation,
 polyuria, pallor
Aortic stenosis, vomiting
Hypertension
Retinopathy
Urine shows proteinuria
Metastatic calcification as revealed by x-
rays
Generalized osteoporosis
 T/t includes discontinuation of vit D &

19. References :-
Essential Pediatrics by O . P . Ghai
Textbook of Preventive & social medicine by K .
Park
www.mc.vanderbilt.edu

20. THANK YOU