NUTRITION SUPPLEMENTATION STUDIES IN SICKLE CELL DISEASE

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For severaldecadesit has been recognizedthat childrenwithsicklecell disease(SCD), especiallythosewithHbSS genotypeSCD (SCD-SS), have poorgrowthanddelayed maturation.In addition,childrenwith$CD experiencefrequent SCD-reiated painandfever episodesand alsoinfection. Increasednutrientrequirementsand/orpoornui/;iJonalstatus have been documentedin childrenwithSCD suggestingthat chronicundemutritionmaycontributeto poorhealthoutcome, growthfailureand delayeddevelopment.Low serumlevelsof vitaminAand vitaminBehavebeen documentedinchildren withSCD suggestingthatdietary intakeof thesemicronutribentsmay notbe adequ._ tomeet the increasednutrient needsof childrenwith SCD. The proposedstudyconsistsof twoprojectsto determinewhether supplementationof vitamin Aor vitaminB6,,can improvehealth outcomes,nutritionalstatus,growthand hematologicstatus in childrenwithSCD-SS. Our preliminarydata fromprepubertalchildrenwithSCD showthat66% havesuboptimalvitaminA status(serumretinol< 30 pg/dL),and that thosechildrenwithsuboptimalstatushavemore frequenthospitalizations, have reducedbodymass index,and poorerhematologicstatusthan those withnormalvitaminA status. Furthermore,preliminarystudiesinchildren andadolescentswithSCD showthat suboptimalvitamin Bestatus(serumpyridoxal5'-phosphate[PLP]< 20 nmol/L)is alsoprevalent(77%), andthat low serumBeconcenltationis associatedwithpoornutritionalstatus as indicatedbyreduced bodymassindex,weightand mid-armcircumferenceandalsowithpoorerhematologicstatus. The firststudyis a randomizedplacebo-controlclinicaltrialto determinethe effectof vitaminA supplementationat thecurrentRecommended DietaryAllowance(RDA) on numberof hospitalizations,the numberand lengthof both SCD-related and nonSCD-related diseaseevents, on growth,bodycomposition,hematologicstatus,rod cell integrity,and immunestatus in prepubedal children(ages 2.0 to 9.9 years) withSCD. Seventy-five childrenwithSCD will be screenedforvitaminA status and44 subjectswith serumretinollevels< 30 pg/dLat screeningwillberandomizedto receiveeitherthe RDA for vitaminA daily or placebofor 12 months. The secondstudywill explore the effectof vitaminB, supplementationat twodoseson growth and nutritionalstatus and hematologicalindicesofSCD diseaseseverityinchildrenand adolescents (ages 6.0 to 17.9 years) with SCD. A total of 100 childrenand adolescentswithSCD and 100 healthycontrols,similarinage, genderand ethnicbackground,will bescreenedto documentthe prevalenceof vitaminBedeficiencyinchildrenwithSCD. Forty childrenwithserumPLP levels< 20 nmol/1,will be identifiedandrandomizedto receive either5 mg/day or25 rag/day vitaminBefor 12 months. Forboth supplementationstudies,assessmentswill be madeat baseline,3, 6, 9 and 12 months. These two projectswillprovidesystematicinvestigationsof theroles of both vitaminA and vitaminBeinimprovinghealth outcomes,growthand nutritionalstatus inchildrenwithSCD andwill potentiallyresultin cost-effectivenutritional interventionsthat can bequicklyimplementedintothe standardof care for thesechildren.