vitamin D deficiency


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vitamin D deficiency

  1. 1. Resource Person:-Prof.Dr.A.K.DuttaPresented by:- Prateek Singh
  2. 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. 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. 4. Dietary sources ofvitamin-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. 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. 6. These lead to:- Learning disability Impaired work capacity. Increased susceptibility to infection
  7. 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. 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. 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. 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. 11.  2 nd stage:- Relative Hyperparathyroidism Phosphaturia Negative phosphorus balance Hypophosphatemia
  12. 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. 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. 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. 15. Diagnosis:
  16. 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. 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. 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. 19. References :- Essential Pediatrics by O . P . GhaiTextbook of Preventive & social medicine by K . Park
  20. 20. THANK YOU