Introduction

Functions

Osteoblast

Bone Forming CellSecrete CollagenRelease ALP

Hydrolyses Phosphoryl Etanolamine

Liberates P++ Ca & P Products

( Howland Formula )Mineralization( Ossification )

Osteoclast

Bone Resorping CellRich in Acid PhosphataseMembraneouse Growth

Transverse Diameter of Bone

Cartilaginous Growth

Length of BoneZPC Formation Dependent On

Howland Formula In BLood

PTH

Bone(+) Bone Resorption

Kidney

Ca Reabsorption P Reabsorption

(+) 1 Hydroxylation of Vit.D

Intestine Ca Absorption

Serum Ca Serum P

Calcitonin Serum Ca

SteroidsCatabolic Effect on Bone

Anti-vitamin D Ca Absorption

Vitamin D

Daily NeedsFull Term400 - 800 IU/day

Pre Term800 - 1000 IU/day

Source

Endogenous7 Dehydrocholesterol in Skin

UVR Colcalciferol

( Vit. D3 )

Animal- Fish Liver Oil- Egg Yolk

D3

Plant- Irradiated Green Plants- Vegetable Oils

D2

NB.Cow Milk & Breast Milkare Poor Sources

Metabolism

HepaticActivation

25 Hydroxylase

25-Hydroxy cholecalciferol

RenalActivation

1 Hydroxylase

1,25-Dihydroxy cholecalciferol

- Low Ca , P- PTH

24 Hydroxylase

24,25-Dihydroxy cholecalciferol

- High Ca , P & Steroid

Action

Bone

Low Physiological DoseMineralisation

Indirectly

High Toxic DoseDemineralisation

Directly

Kidney Ca & P Reabsorption

Intestine Ca & P Absorption

Vitamin D Cycle

1- Introduction.mmap - 10/07/2012 - Mohammed Safian

14

Vit. D Def. Rickets

Causes

Rachitogenic Diet

Cow Milk - Vit. D- Ca/P ratio = 2/1

Prolonged BF e`/o Vit. D Supp.

Excess Phytates

Vit. C Gut acidity

Beverages Gut alkalinity

Inadequate Sun Exposure ?

- Glass Windows- Clowdy Weather- Polution- Infants if Overwrapped

Dark Skin

Symp.

M/C 6-24 mths.

Autonomic- Irretability- Anorexia- Sweating

Delayed Motor Milestones eg: Crowling & Walking

Delayed Teeth EruptionDeformities

Fractures - Asymptomatic- Green Stick Fracture

Recurrent Chest Infections

Tetany - Late , Rare- Most Dangerous

Sign

Skeletal

Skull

- Frontal & Parietal Bossing- Box Shaped Skull ( Caput Quadratum )- OFC- Delayed Closur Of A.F- Delayed Teeth Eruption- Cranio Tabes ( Only in 1st. year )

Thorax- Rickety Rosary- Harison`s Sulcus- Longitudinal Groove- Pigeon Chest

Limbs- Broadning- Marfan Sign- Genue Varum ( Bow Legs )- Genue Valgum ( Knok Knees )

Vertebral Columns

KyphosisSmoothRondedCorrectable

Lumber LordosisScoliosis

Pelvis- Inlet Contraction- Outlet Contraction

Non-Skeletal

Muscular Hypotonia

- Delayed Motor Milestones- Abdominal Distension- Spine Deformities- Visceroptosis- Acrobatic Rickets

Abdomen

Pot Belly Protruded Abd.

Palpable Liver & Spleen

Ptosis

Enlagment- RES Hyperplasia- Von Jack's Anemia- Hepatic Rickets- Cystinosis

Nurological

EarlyHypotonia

LateTetany- Manifist

- Latent

Infections Susceptibility to Infections

Pseudoleukemia Infantum

Von Jack's Anemia

anemia ass.e` HSM & GLN

CBC- Anemia- TLC ( 25000/mm )

due toEffect Of Vit. D DeficiencyOn Hematopoietic System

Invst.

Serum Ca

Normal , Low NormalN: 9 -11 mg %

Hypocalcemia ( Tetany ) if

- Failure of P.Th. Gland- Vit. D Dose e` No Ca- Exhaustion of Ca Bone Stores- Chest Infection Alkalosis

Serum P1.5 - 3 mg %N: 4.5 - 6.5 mg %earliest to return normal e` ttt

Serum ALP

N: 145 - 500 IU/LLeast to Return Normal

ALP + Rickets

- PEM- Cong.Hypophosphatasia- Zinc depletion

tttVit. D

Oral2000 - 6000 IU/day

Till Recovery

IMStoss Therapy =600.000 IU/dose

Repeated after 2 wks.adequate Ca , Ph.

2- Vit. D Def. Rickets.mmap - 10/07/2012 - Mohammed Safian

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Renal rickets ( A )

Glomerular

Causes

Phosphate Retention 2ry Hyperparathyroidism Bone Resorption Osteitis Fibrosa Cystica

Hydroxylation of Vit. D

Metabolic Acidosis Solubilization of Ca Salts in Bone

Cl.P

- Rickets- Renal Disease- Growth Failure- Dwarfism- Tetany is Rare dt. Acidosis

Invst.Lab. PTH , P , ALP The Only Rickets e` P

X-Ray- Epiphyseal Changes of Rickets- Osteitis Fibrosa Cystica

ttt

- Renal Transplantation ( of Choice )- Active Vit D ( 1.25 (OH)2 D3- Ca- Low P Diet & P Chelators ( Ca Carbonat )- ttt of Acidosis ( NaHCO3 )

Renal Osteodystrophy Chronic renal failure

Tubular

Path.- Defect In PCT- Renal Absorption OF Phosphate- Activation Of Vit. D

invst.

- P is Low in Blood & v.High in urine- Normal urinary CAMP- Normal PTH- High ALP- Ca is low or normal

ttt- Oral P Supp.- Ca- Active Vit. D ( 1.25 (OH)2 D3

Primary Familial Hypophosphatemic Rickets ( XLD )

Fanconi $

Def.- Defect in PCT- Absorption of : P, AA , Glucose , HCO3 , Na , K

Causes

- Idiopathic AD or AR- Lowe $- IEM: Cystinosis ( Lignac $ )- Lead & Hg poisoning- Outdated Tetracyclins

Renal rickets .mmap - 10/07/2012 - Mohammed Safian

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Renal rickets ( B )

Fanconi $

Def.- Defect in PCT- Absorption of : P, AA , Glucose , HCO3 , Na , K

Causes

- Idiopathic AD or AR- Lowe $- IEM: Cystinosis ( Lignac $ )- Lead & Hg poisoning- Outdated Tetracyclins

Cystinosis

Def.- AR Disorder- Accumulation of Cystien Crystals- dt efflux from cells

Cl.P

Renal - Fanconi $- CRF

RES - HSM- G. Lumphadenopathy

Cornea Photophopia

Melanocytes - Blond Hair- Fair Skin

Bone Marrow Pancytopenia

Invst. Mesure Cystine Contentin WBCs & Fibroblast

ttt Cystien ChelatorCysteamin

Renal rickets ( B ).mmap - 12/07/2012 - Mohammed Safian

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Tetany

Def. Excitability Of Central & Peripheral Neurons

dt. Ionizable Ca, Mg or Alkalosis

Hypocalcemic

PTH

Transient Neonatal HypocalcemiaEarly 1st. 72 hrsLate 5 -10 days

Hypoplasia ( DiGeorge )ThyroidectomyAutoimmuneFamilialInfiltration ( Fe - Cu )

RicktsVit. D Def.

Vit. D e'/o Ca Supp. Of Bone Stores

Failure Of Para Th. GlandVDDR Type I & II

Steatorreah & Sever Liver Dis.

Hypomagnesimic

Nutritional InsufficiencyTPN e'/o Sufficient MgChr. DiarrheaTransfusion e' Citrsted BloodNephrotoxic & Diuretic Medications

Alkalotic

Respiratory Alkalosis Hyperventilation

Metabolic Alkalosis Vomiting Alkali Therapy

Cl/P

Latent Tetany

Chvostik SignTapping Facial n.

Deviation Of Angle Of Mouth

Troussau SignIsch. Of Forearm For 3 min.

Carpal Spasm

Pernoeal SignTapping Pernoeal n.

Dorsiflextion & Eversion Of Foot

Erb Test< 5 mA

Muscle Contraction Q-T Interval

- Ca 7- 9 mg % ,or- Mg 1.2 - 1.5 mg %

Manifest Tetany

Carpopeadal SpasmPainful

Laryngismus StridulousCroup & Cyanosis

ConvulsionsGeneralized

Numbnes & ParathesiaHand & Feet

- Ca < 7 mg % ,or- Mg < 1.2 mg %

Invst.

- Ca ( N: 9-11 mg % )

- Mg ( N: 1.5 - 1.8 mg % )

- PH ( N: 7.35 - 7.45 )

ttt

Ca Gluconate 10%- 1-2 ml/kg- IV over 10 min.- e' Monitoring of HR

Mg Sulphate 50%- 0.2 ml/kg- Deeply IM

Psychogenic HyperventilationRebreathing into Bag

CO2

NB

if Convulsing

ABC

Anti Convulsion

Diazipam

if Laryngeal SpasmO2

Tracheostomy if Needed

Tetany.mmap - 16/06/2012 - Mohammed Safian

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Hypervitaminosis D

Def.> 20.000 IU Vit. D for 1- 3 mths.

ttt

Stop Vit. D intake Ca in Diet

ChelatorsAl OHNa Versenat ( EDTA )

Cortisone in Sever Cases

Calcitonin New Line of ttt.

CL/P

Kidney

- Polyuria , Polydepsia- Dehydration- Nephrocalcinosis- Renal Stons- RF

GIT

- Anorexia- Constipation- Vomiting- Pain ( acute pancreatitis )

CVS- HTN- Calcivication of Aortic Valve

CNS- Confusion- Irretability

BloodAnemia

SystemicMetastatic Calcification

Vit K

- Oxidizing agent Hemolysis- ( Jaundice, Kernecterus)

Vit A

- Nasea Vomiting- ICP ( Pseudo tumor cerebri )- Bulge of fontanelles, Papilledema

Hypervitaminosis D.mmap - 12/07/2012 - Mohammed Safian

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