Presentation is loading. Please wait.

Presentation is loading. Please wait.

Vitamin D Deficiency Rickets

Similar presentations

Presentation on theme: "Vitamin D Deficiency Rickets"— Presentation transcript:


2 Vitamin D Deficiency Rickets
Fan Yang Associated Professor Pediatric Department

3 Vitamin D Vitamin D comprises a group of sterols
Vitamin D2 = ergocalciferol Completely synthetic form produced by the irradiation of the plant steroid ergosterol Vitamin D3 = cholecalciferol Produced photochemically by the action of sunlight or ultraviolet light from the precursor sterol 7-dehydrocholesterol Vitamin D = calciferol

4 VITAMIN D Humans & animal utilize only vitamin D3 & they can produce it inside their bodies from cholesterol. Cholesterol is converted to 7-dehydro-cholesterol (7DC), which is a precursor of vitamin D3.

5 VITAMIN D Exposure to the ultraviolet rays in the sunlight convert 7DC to cholecalciferol. Vitamin D3 is metabolically inactive until it is hydroxylated in the kidney & the liver to the active form 1,25 Dihydroxycholecalciferol. 1,25 DHC acts as a hormone rather than a vitamin, endocrine & paracrine properties.

6 Vitamin D: The Sunshine Vitamin
Not always essential Body can make it if exposed to enough sunlight Made from cholesterol in the skin


8 Formation of Vitamin D Skin (UV light)
7-dehydro cholesterol  Vitamin D3 Ergosterol  Vitamin D2 Liver OH-group added 25-Hydroxy vitamin D3 Storage form of vitamin (~3 months storage in liver) Kidney OH-group added by 1-hydroxylase 1,25-dihydroxy vitamin D3 Active form of vitamin D, a “steroid hormone” OH-group added by 24-hydroxylase 24,25-dihydroxy vitamin D3 Inactive form of vitamin D, ready for excretion


10 FUNCTIONS Calcium metabolism: vitamin D enhances ca absorption in the gut & renal tubules. Cell differentiation: particularly of collagen & skin epithelium Immunity: important for Cell Mediated Immunity & coordination of the immune response.

11 Vitamin D - Functions Bone development
Calcium absorption (small intestine) Calcium resorption (bone and kidney) Maintain blood calcium levels Phosphorus absorption (small intestine) Hormone Regulation of gene expression Cell growth

12 Vitamin D Functions

13 Vitamin D Affects Absorption of Dietary Ca
Groff & Gropper, 2000 1,25-(OH)2 D binds to vitamin D receptor (VDR) in nucleus Increase in calbindin (Ca-binding protein)

14 Vitamin D Affects Absorption of Dietary Phosphorus
1,25-(OH)2 D3 increases activity of alkaline phosphatase Hydrolyses phosphate ester bonds Releases phosphorus Increase in phosphate carriers

15 Vitamin D deficiency

16 Etiology 1. Lack of sunshine due to: 1) Lack of outdoor activities
2) Lack of ultraviolet light in fall and winter 3) Too much cloud, dust vapour and smoke

17 Etiology 2. Improper feeding: 1) Inadequate intake of Vitamin D
Breast milk IU/100ml Cow’s milk IU/100ml Egg yolk IU/average yolk Herring IU/100g 2) Improper Ca and P ratio

18 Etiology 3. Fast growth, increased requirement Relative deficiency
4. Diseases and drug: Liver diseases, renal diseases Gastrointestinal diseases Antiepileptic Glucocorticosteroid

19 GROUPS AT RISK Infants Elderly Dark skinned Covered women
Kidney failure patients Patients with chronic liver disease Fat malabsorption disorders Genetic types of rickets Patients on anticonvulsant drugs

20 Vitamin D deficiency Deficiency of vitamin D leads to:
Rickets in small children. Osteomalacia Osteoporosis

21 Parathyroid Hormone (PTH)
Calcium-sensor protein in the thyroid gland Detects low plasma calcium concentrations Effects of parathyroid hormone Urine / kidneys Increases calcium reabsorption Increases phosphorus excretion Stimulates 1-hydroxylase activity in the kidneys 25-OH D  1,25-(OH)2 D PTH required for resorption of Ca from bone Activates a calcium pump on the osteocytic membrane Activates osteoclasts

22 Pathogenesis Vitamin D deficiency Absorption of Ca, P Serum Ca
Function of Parathyroid

23 Pathogenesis PTH High secretion P in urine Decalcification of old bone
P in blood Ca in blood normal or low slightly Ca, P product Rickets

24 Pathogenesis Low secretion of PTH Failure of decalcification of bone
Low serum Ca level Rachitic tetany

25 Clinical manifestation
Rickets is a systematic disease with skeletons involved most, but the nervous system, muscular system and other system are also involved.

26 Clinical manifestation
Early stage Usually begin at 3 months old Symptoms: mental psychiatric symptoms Irritability, sleepless, hidrosis Signs: occipital bald Laboratory findings: Serum Ca, P normal or decreased slightly, AKP normal or elevated slightly,25(OH)D3 decreased Roentgenographic changes: normal or change slightly

27 Clinical manifestation
Advanced stage On the base of early rickets, osseous changes become marked and motor development becomes delayed. 1. Osseous changes: 1) Head: craniotables, frontal bossing, boxlike appearance of skull, delayed closure of anterior fontanelle 2) Teeth: delayed eruption, with abnormal order, defects 3) Chest: rachitic rosary, Harrison’s groove, pigeon chest, funnel-shaped chest, flaring of ribs

28 Clinical manifestation
4) Spinal column: scoliosis,kyphosis, and lordosis 5) Extremities: bowlegs,or knock knee, greenstick fracture 6) Rachitic dwarfism 2. Muscular system: potbelly, late in standing and walking 3. Motor development: delayed 4. Other nervous and mental symptoms

29 Clinical manifestation
Laboratory findings: Serum Ca and P decreased Ca and P product decreased AKP elevated Roentgenographic changes: Wrist is the best site for watching the changes. Late appearance of ossification center Widening of the epiphyseal cartilage Blurring of the preparatory calcification line metaphyses like a cup rarefaction of the bone thinned cortex of the shaft of long bone

30 Clinical manifestation
Healing stage: Symptoms and signs of Rickets alleviate or disappear by use of appropriate treatment. The blood chemistries become normal, except AKP may be slightly elevated. Sequelae stage: All the clinical symptoms and signs disappear. Blood Chemistries and X-ray changes are recovered, but osseous deformities may be left. Usually seen in Children after 3 years old.

31 Rachitic vs. normal chick
Rickets due to deficiency of vitamin D, Ca, or P



34 Vitamin D Deficiency - Rickets

35 A B C (B) Healing after 28 days of treatment
Rickets in wrist - uncalcified lower ends of bones are porous, ragged, and saucer-shaped (A) Rickets in 3 month old infant A (B) Healing after 28 days of treatment (C) After 41 days of treatment B C





40                                 Approved for: 1                                       Rickets

41 Diagnosis Assessed according to the followings: 1. History
2. Physical examination 3. Laboratory findings 4. Roentgenographic changes

42 Differential diagnosis
1. Hypophosphatemic Vitamin D resistant rickets 2. Rickets of Vitamin D dependency 3. Distal renal tubular acidosis 4. Cretinism 5. Chondrodystrophy


44 Treatment 2. Prevention of complications 3. Special therapy
1. Food and nursing care 2. Prevention of complications 3. Special therapy 1) Vitamin D therapy A. General method Vitamin D IU/day for 2-4 weeks, then change to preventive dosage (400IU). B. A single large dose: For severe case, or Rickets with complication, or those who can’t bear oral therapy. Vitamin D IU, im, preventive dosage will be used after 2-3 months.

45 Treatment 2) Calcium supplementation:
only used for special cases, such as baby fed mainly with cereal, or infants under 3 months of age, and those who have already developed tetany. Dosage:1-3 g/day. 3) Plastic therapy: In children with bone deformities after 4 years old plastic surgery may be useful.

46 Prevention 1. Pay much attention to the health care of pregnant and lactating women, instruct them to take adequate amount of vitamin D. 2. Advocate sunbathing 3.Advocate breast feeding, give supplementary food on time

47 Prevention 4. Vitamin D supplementation:
In prematures, twins and weak babies, give Vitamin D 800IU per day, For term babies and infants the demand of Vitamin D is 400IU per day, For those babies who can’t maintain a daily supplementation, inject muscularly Vitamin D IU.

48 Prevention 5. Calcium supplementation:
0.5-1gm/day, for premature, weak babies and babies fed mainly with cereal

49 Sources of Vitamin D Sunlight is the most important source
Fish liver oil Fish & sea food (herring & salmon) Eggs Plants do not contain vitamin D3

50 Vitamin D - Sources Not found naturally in many foods
Synthesized in body Plants (ergosterol) Sun-cured forages Fluid milk products are fortified with vitamin D Oily fish Egg yolk Butter Liver Difficult for vegetarians

51 TOXICITY Hypervitaminosis D causes hypercalcemia, which manifest as:
Nausea & vomiting Excessive thirst & polyuria Severe itching Joint & muscle pains Disorientation & coma.

52 Vitamin D Toxicity Calcification of soft tissue Hypercalcemia
Lungs, heart, blood vessels Hardening of arteries (calcification) Hypercalcemia Normal is ~ 10 mg/dl Excess blood calcium leads to stone formation in kidneys Lack of appetite Excessive thirst and urination Infants:

53 Thank You!

Download ppt "Vitamin D Deficiency Rickets"

Similar presentations

Ads by Google