Vitamin d deficiency & rickets

presentation on vitamin D deficiency in children

1. Vitamin D deficiency in Children
Abdulmoein E. Al-Agha,
Professor of Pediatric
Endocrinology,
King Abdulaziz
UniversityHospital ,
Jeddah, SaudiArabia.
http://aagha.kau.edu.sa

2. Objectives
•Introduction.
•Vitamin Dmetabolism.
•Vitamin Dresources.
•Vitamin DBenefits.
•Both on skeletal &‘extra-skeletal’ benefits of vitaminD.
•Vitamin DDeficiency
•Definition.
•Causes.
•Symptoms &signs.
•Laboratoryfindings.
•Radiologicalfindings.
•Prevention &Treatment.

3. Introduction
•Vitamin D is an extremely important vitamin that has powerful effects on several
systems of thebody.
•Unlike other vitamins, vitamin D functions like a hormone & every single cell in the
body has a receptor forit.
•Vitamin D deficiency is very common medical condition in SaudiArabia.
•It's estimated that about 1 billion people worldwide have low levelsofthe vitaminD.
•All age groups areaffected!
•41.6% of adults in the US aredeficient.
•69.2%inHispanicsand 82.1%inAfrican-Americans.
•90 -95 % prevalence in SaudiArabia.

4. Vitamin D resources
•Both ergocalciferol (D2) & cholecalciferol (D3) are equipotent, both
increase vitamin Dstores, however, recent evidence suggests that
vitamin D3 increases vitamin D concentrations two -to threefold more
thanD2.
•ThecommonestdietaryresourcesofvitaminD3arefish (e.g., salmon
and tuna), cod liver oil, milkand all fortifiedmilkproducts, whereas
vitamin D2is foundin plant sources like yeast andmushrooms.
•Vitamin D is available commercially as ergocalciferol, cholecalciferol,
one alpha calcidiol &calcitriol.

5. Vitamin Dresources
•Nearly90%ofvitaminDrequirementismetbyadequateexposureofthe
skintosunlightthroughtheactionofultraviolet B radiations (UVB) and
remaining 10% is said to meet throughdiet.
•TheWHOexpertconsultationstatesthathumanscangetvitaminD from
abundant sunshine, by exposing 18% of body surface area(without
sunscreen)tomid-daysun(10am-3pm)foraverageof15-30min/day.
•Pollution hinders solar UVB rays reaching the ground.
•Lack of space, overcrowdings prevent the direct sunlight reaching inside
most parts in urban regions with limited outdoor activities.
•High phytate (Chapati bread) and/ or low calcium diet causes vitamin D
deficiency by impairing its absorption.

7. Vitamin DBenefits

8. Vitamin D benefits on the skeleton
•Vitamin D is extremely important for the human's skeleton & non
skeleton tissues right from conception throughout lifespan.
•It has major implications on bone health, since approximately 40% -
60% of total skeletal mass at maturity is accumulated during childhood
& adolescence.
•Has profound effect on growth & development during childhood.
•Regulates calcium & phosphorus balance for bone mineralization &
bone remodelling.

9. Vitamin Disnot only just for skeletons!!

10. Extra -skeletal Benefits
•VitaminDacts aspotentantioxidantprotectingagainstfreeradical
damage & inducer of cellular differentiation, protecting against
carcinogenesis.
•Hasa roletofightagainstseriousinfections,bycontrollingTcell antigen
receptor signaling and activation of human Tcells.
•Sincethesediseasesaremultifactorial,optimumvitaminDlevelsmay
notprevent these diseases, but their risk islowered.
•In pediatric age group, subclinical vitamin D deficiency & non-exclusive
breastfeeding in the first 6 months of life were found to be significant
increase risks for acute respiratory tract infections , tuberculosis as well
otherdiseases.
•Significant inverserelationship between vitamin D levels &severity of
Asthma, COPD were observed in somestudies.

11. Role of vitamin D in reducing risk of AutoimmuneDisease
•VitaminDsupplementationisassociatedwithlowerriskof
autoimmunediseases.
•InFinnishbirthcohortstudyof10,821children, supplementationwith
vitaminDat2000IU/dreducedtheriskoftype 1diabetesby
approximately78%,whereaschildren who were at risk for rickets had
3-fold higher risk for type 1diabetes.
•In a case-control study of 7 million US military personnel, high
circulating levels of vitamin D were associated with a lower risk of
multiplesclerosis.
•Similarassociationshavealsobeendescribed for vitamin D levels&
rheumatoidarthritis.

12. When to say vitamin D isdeficient??
•VitaminDdeficiency is typically diagnosed by measuring the
concentration of the serum level of 25-hydroxy vitamin D, which is
the most accurate measure of stores of vitamin D in thebody.
•Deficiency: < 20ng/ml.
•Insufficiency: 20–29ng/ml.
•Normal: 30–100ng/ml.
•VitaminDlevelsfallingwithinthisnormalrangepreventclinical
manifestations of vitamin D insufficiency /deficiency.
•Multiply ng/ml by 2.5 to getnmol/l

13. Rickets/Osteomalacia
•Ricketsisdiseaseof thegrowingbonesinwhich defective
mineralizationoccursinbothbone& cartilageof theepiphyseal
growthplates.
•Isassociatedwithgrowth retardation&skeletal deformities:
•skeletal muscleshavevitaminDreceptor.
•vitaminDdeficiencycausesmuscleweakness.
•Osteomalaciaisa disorderof thematurebonein which
mineralizationof new osteoidboneis inadequateordelayed.

14. Types
•HypocalcaemicRickets(commonesttype).
•HypophosphatemicRickets(notcommon).
•CombinedRickets(combinationofhypocalcemia&hypophosphatemia).

15. Hypocalcaemicrickets(withsecondarilyelevated
parathyroidhormonelevels)
•Lackof vitaminDdueto:
•Decreasedsunexposure.
•Dietary-deficientintake.
•Malabsorptiondiseases thataffectsabsorptionofvitaminD
(e.g.celiacdisease,CF,chronic diarrhea…etc)
•Chronicliverdiseases(affectsconversionof cholecalciferolto
calcidiol).
•Anticonvulsantdrugs(phenytoin,phenobarbitoneduetoincreased
metabolism of vitamin DbyinducingcytochromeP450activity).

16. NutritionalRickets
•CommonestcauseinSaudiArabia&indevelopingcountries.
•Lackof exposuretoU/Vsunlight.
•Dark skin.
•Coveredbody.
•Keptin-door.
•Exclusivebreastfeeding.
•LimitedintakeofvitaminDfortifiedmilk&diaryproducts.
•Peak prevalence duringperiods of rapidgrowth:
•Infancy.
•Puberty.

17. other causes of vitamin D deficiency
•Celiac disease.
•Pancreatic insufficiency.
•Cystic fibrosis.
•Hepato-biliary disease
•Biliary Artesia.
•Cirrhosis.
•neonatal hepatitis.
•Anti-convulsant.
•Phenobarbitone.
•Phenytoin.
•Diet
•Excess of phytate in diet with impaired calcium absorption (chapati
flour).

18. Renal Rickets
Chronic renal failure (Renal Osteodystrophy):
•Occurs due to lack of synthesis of active form (1,25-dihydroxy vitamin D) as consequences of
1-α-hydroxylase enzyme deficiency.
Renal Tubular acidosis:
•Metabolic acidosis from proximal or distal tubular disease.
•Fanconi syndrome (generalized form of RTA)
•associated with cystinosis, tyrosinemia & Wilson's disease
•Accompanied with other urinary loss:
•Calcium.
•Phosphate.
•Glucose.
•Protein.
•Isolated or generalized forms.
•Hereditary hypophosphatemic rickets.

19. HereditaryRickets
•Hypophosphatemicrickets(VitDresistant).
•VitaminDdependentrickets.

20. VitaminDdependentrickets
Type1
•Rare,autosomalrecessive.
•Lackof1αhydroxylaseenzyme.
•Clinically&biochemicallylikenutritionalricketsexceptitappearsearlyat3-4
months.
Type2
•Rareautosomalrecessivedisorder.
•1αhydroxylaseenzymeispresent.
•LackofCalcitriolreceptors.
•CommoninArabs.
•Baldness.
•Severelyaffectedindividuals.
•Unresponsivetotreatment.

29. Prevention of vitaminDdeficiency
•In premature infants, 800 IU of vitamin D & 150-200 mg/kg of calcium
are recommendeddaily.
•In neonates, 400U of vitamin D & 200 mg of calcium are
recommended daily.
•In infants (after neonatal period) up to 1 year of age, 400U of vitamin
D/day and 250-500 mg/day of calcium are recommendeddaily.
•Ages from 1-18 years, 600 U vitamin D/day and 600-800 mg/day of
calcium are recommendeddaily.

30. Treatment of Vitamin Ddeficiency
•Forpremature neonates&infants up to 1-year of age:
•1000-2000 units& elemental calcium of 70-80 mg/kg/day.
•For children 1-18 years:
•3000-6000 unitof vitamin D daily & calcium 500-800 mg daily.
•It is recommended that larger doses of vitamin D up to 50,000 IU/week
for 8 -12 weeks, then to measure serum vitamin D, if restoredto normal
to continue on prophylactic doses (especially in communities with low
sun exposure).

31. Conclusions
•Vitamin D deficiency is incredibly common & most people are unaware ofit.
•Symptoms are often subtle &non-specific.
•Advisable,allagegroups to screen for itsdeficiency.
•Fortunately, a vitamin D deficiency is usually easy to betreated.
•Highly advisable, increase people awareness for its deficiency and broadcast
preventivemeasuressuchas,eitherincreasesunexposure,consumemoreof
vitamin D fortified food / formulas, fish & salmon or fortified dairyproducts.
•Encourage either sun-exposure (15 -30 minutes per day (longer with darker skin)
or vitamin Dsupplementations.
•The recommended daily intake is usually 400–800 U,butmany experts advise to
have up to 1000unit/day.

32. Thankyou