Rev. paul. pediatr. vol.33 número3

RevPaulPediatr.2015;33(3):286---293

www.rpped.com.br

REVISTA

PAULISTA

DE

PEDIATRIA

ORIGINAL

ARTICLE

Prevalence

of

vitamin

D

deficiency

and

associated

factors

in

women

and

newborns

in

the

immediate

postpartum

period

Mara

Rúbia

Maciel

Cardoso

do

Prado

,

Fabiana

de

Cássia

Carvalho

Oliveira

,

Karine

Franklin

Assis

_,

_Sarah

_Aparecida

_Vieira

_Ribeiro

_,

Pedro

Paulo

do

Prado

Junior

_,

_Luciana

_Ferreira

_da

_Rocha

_Sant’Ana

_,

Silvia

Eloiza

Priore

_,

_Sylvia

_do

_Carmo

_Castro

_Franceschini

a_{UniversidadeFederaldeVic¸osa(UFV),Vic¸osa,MG,Brazil} b_{UniversidadeFederaldoEspíritoSanto(UFES),Vitória,ES,Brazil}

c_{UniversidadeFederaldeMinasGerais(UFMG),BeloHorizonte,MG,Brazil}

Received30September2014;accepted18January2015 Availableonline27June2015

KEYWORDS

VitaminDdeficiency;

Newborns; Women;

Postpartumperiod

Abstract

Objective: ToassesstheprevalenceofvitaminDdeficiencyanditsassociatedfactorsinwomen andtheirnewbornsinthepostpartumperiod.

Methods: Thiscross-sectionalstudyevaluatedvitaminDdeficiency/insufficiencyin226women andtheirnewbornsinVic¸osa(MinasGerais,BR)betweenDecember2011andNovember2012. Cordbloodandvenousmaternalbloodwerecollectedtoevaluatethefollowingbiochemical parameters:vitaminD,alkalinephosphatase,calcium,phosphorusandparathyroidhormone. Poissonregressionanalysis,withaconfidenceintervalof95%,wasappliedtoassessvitaminD deficiencyanditsassociatedfactors.Multiplelinearregressionanalysiswasperformedto iden-tifyfactorsassociatedwith25(OH)Ddeficiencyinthenewbornsandwomenfromthestudy.The criteriaforvariableinclusioninthemultiplelinearregressionmodelwastheassociationwith thedependentvariableinthesimplelinearregressionanalysis,consideringp<0.20.Significance levelwas˛<5%.

Results: From226womenincluded, 200(88.5%)were20---44 yearsold;themedianagewas 28years.Deficient/insufficientlevelsofvitaminDwerefoundin192(85%)womenandin182 (80.5%)neonates.Thematernal25(OH)Dandalkalinephosphataselevelswereindependently associatedwithvitaminDdeficiencyininfants.

DOIoforiginalarticle:http://dx.doi.org/10.1016/j.rpped.2015.01.006 ∗_{Correspondingauthor.}

E-mail:mara.prado@ufv.br(M.R.M.C.Prado).

Conclusions: ThisstudyidentifiedahighprevalenceofvitaminDdeficiencyandinsufficiency inwomenandnewbornsandtheassociationbetweenmaternalnutritionalstatusofvitaminD andtheirinfants’vitaminDstatus.

© 2015 Sociedadede Pediatriade São Paulo. Publishedby Elsevier Editora Ltda. Allrights reserved.

PALAVRAS-CHAVE

Deficiênciade

vitaminaD;

Recém-nascidos; Mulheres;

Períodopós-parto

PrevalênciadedeficiênciadevitaminaDefatoresassociadosemmulhereseseus

recém-nascidosnoperíodopós-parto

Resumo

Objetivo: AvaliaraprevalênciadedeficiênciadevitaminaDeosfatoresassociadosemmulheres erecém-nascidosnoperíodopós-parto.

Métodos: Estudodedelineamentotransversal;avaliou-seadeficiência/insuficiênciade vitam-inaDem226mulhereseseusrecém-nascidosnomunicípiodeVic¸osa(MG),entredezembrode 2011enovembrode2012.Coletaram-se5mLdesanguedocordãoumbilicalesanguevenoso materno afim deavaliarosparâmetrosbioquímicos: vitaminaD, fosfatasealcalina,cálcio, fósforoeparatormônio.Usou-seregressãodePoissoneadotou-seaRazãodePrevalência(95% IC), afimdeseavaliaradeficiênciadevitaminaDefatoresassociados.Fez-seaanálisede regressãolinearmúltiplapara identificarosfatoresassociados àdeficiênciade25(OH)Ddos recém-nascidosedasmulheresdoestudo.Ocritérioparainclusãodasvariáveisnaregressão linearmúltiplafoiarelac¸ãocomavariáveldependentenaanálisederegressãolinearsimples, considerandop<0,20.Oníveldesignificânciaadotadofoi␣<5%.

Resultados: Das226mulheres,200(88,5%)tinhamentre20e44anos;amedianafoide28. Encontrou-seprevalênciadeníveisdeficientes/insuficientesdevitaminaDem192(85%) mul-heres e 182(80,5%)recém-nascidos. A 25(OH)D maternae afosfatase alcalina maternase comportaramcomopreditoresindependentesdadeficiênciadevitaminaDdosrecém-nascidos.

Conclusões: Foipossívelidentificaraaltaprevalênciadedeficiênciaeinsuficiênciadevitamina Dnasmulhereserecém-nascidosemnossomeioearelac¸ãoentreoestadonutricionalmaterno devitaminaDeodorecém-nascido.

© 2015Sociedadede Pediatriade SãoPaulo. Publicado porElsevier Editora Ltda.Todosos direitosreservados.

Introduction

Maternal---fetal vitamin D deficiency (VDD) is currently

a frequent morbidity. Lifestyles, environmental factors

(inadequate sunlight exposure), lack of vitamin D (VD)

supplementation for children and pregnant women and

insufficient intake of that vitamin and/or calcium are

responsibleforthehighprevalenceofVDDindevelopedand

developingcountries.1---3

VDDinapregnantwomanandhernewborn(NB)isclosely associated.4_{There isagreater transferof 25(OH)Dtothe} fetusviatheplacentaduringthelastmonthsofpregnancy, whichisthemainsourceofthisvitaminforinfantsduringthe firstmonthsoflife.5,6_{Additionally,theplacentacontainsVD} receptorsandproducestheenzymethatconverts25(OH)D into itsactive form, therebyincreasing VD levels for the fetus.5

Inthefirstsixtoeightweeksofpostnatallife,theNB’s VDstatusdependsontheVDacquiredbyplacentaltransfer intheuterus,asdemonstratedbyitsdirectassociationwith thelevelsfoundinmaternalblood.6,7_{InmostNBs,VDstock} acquiredfromthemotherrunoutuptotheeighthweekof life.7

StudiescarriedinIndia,UnitedStates,Bangladesh,Korea andother parts of the worldhave shown thatmany chil-drenworldwideareborn withlowVD reservesasa result of high maternal VDD, with a high prevalence of defi-ciency/insufficiency of 25(OH)D, ranging from 22.3% to 73.6%and,therefore,atriskofrickets.1,8---11_Normalplasma levelsofVDpromotetheabsorptionof30%ofdietary cal-ciumandmorethan60---80%duringperiodsofgrowth,due tothehighcalciumdemand.Therefore,duringchildhood, VDDcancausegrowthretardationandboneabnormalities, increasingtheriskoffractureslaterinlife.12 _{Additionally,} lowlevelsof 25(OH)D in cordblood wereassociated with increasedriskofacuterespiratoryinfectionsandwheezing inchildhood.13

288 M.R.M.C.doPradoetal.

thecountryandlocalclothingcustoms.1,4,8,9,13_However,to date,therehasbeennostudyontheprevalenceofVDDin Brazilinnewbornsandwomenintheimmediatepostpartum period.Giventhemagnitudeofthisprobleminthe popula-tion,theaimofthisstudywastoevaluatetheprevalence ofvitaminDdeficiencyandassociatedfactorsinwomenand theirnewbornsinthepostpartumperiod.

Method

This was a cross-sectional study, approved by the

Inter-national Review Board of Universidade Federal de Vic¸osa

(n. 211/2011). A total of 226 women and their newborns

wereevaluatedinthepostpartumperiod,between

Decem-ber2011andNovember2012.

SamplecalculationwasperformedusingEpiInfosoftware

7.0.Forthecalculation, weobtainedthenumberof

new-bornslivinginthecityin2010,addingup806children.We

usedaprevalenceofVDDestimatedat20%10_and95%

confi-dencelevel.To thenumberof188obtainedatthesample sizecalculation,weadded20%forpossiblelosses,resulting in226pairsofmothersandnewborns.

Childrenbornatthestudy hospitalinVic¸osa,with ges-tational age ≥37 weeks and whose mothers signed the informedconsentform,wereincludedinthestudy.Infants that were admitted to the Neonatal Intensive Care Unit, born with congenital malformations, syndromes and the resultoftwinpregnancieswereexcluded.

ObstetricandNBdata(weight,length,head circumfer-ence, ethnicity) were obtained from the Obstetrics Book andBirthcertificates(BC).Socioeconomicandprenatalcare data (including sunlight exposure, use of sunscreens and multivitaminsupplements)wereobtainedthrougha ques-tionnaireappliedtowomenafter30dayspostpartumatthe city’sPolyclinic. The Brazilian Criteria for Economic Clas-sification(ABEP)wasusedforsocioeconomicclassification, whichtakesintoaccounttheownershipofconsumergoods andthefamilyhead’slevelofschooling.16

The skin color of the mother and their newborns was self-reportedandconfirmedintheBCbyresearcherswhen the questionnaire wasapplied, and it wascategorized as Caucasianor non-Caucasian.The sample wasdivided into two groups according to the time of sunlight exposure duringpregnancy:adequate(>60min/week)orinadequate (≤60min/week).17

Plasma levels of 25(OH)D, alkaline phosphatase (AP), parathyroidhormone (PTH), calcium (Ca) and phosphorus (P)wereevaluatedinthewomenandtheirnewbornsinthe postpartumperiod,bycollecting5mLofcordbloodand5mL ofmaternal venousbloodforbiochemicalinVacuette® _gel

tubes. Serumwas separated in a refrigerated centrifuge, dividedintoaliquotsandstoredat−20◦_{Cuntiltheanalyses} were performed. Ca was measured by colorimetric end-pointCalciumArsenazoIII,18_{andAPbyKinetic---IFCCmethod} (Bioclin).18_{25(OH)DlevelsweremeasuredbyLiaison®} com-petitivechemiluminescenceimmunoassay(CLIA-DiaSorin),19 andPTHinaBeckmanimmunochemiluminometricassayby Coulter®_.18 _{pwasobtainedbyUVendpoint.}18

The sample was divided into two groups according to theVDlevelsof newborns andthewomen: VDsufficiency andnon-sufficiency(VD insufficiencyand deficiency).VDD

forwomenandchildrenwasdefinedas25(OH)D<20ng/mL; the insufficiencyof 25(OH)Dbetween ≥20and <30ng/mL, andsufficiency as25(OH)Dlevels ≥30ng/mL.10 _{The cutoff} for highPTH was46pg/mL; forhypocalcemia, plasma cal-cium levels <9mg/dL for children and <8.8mg/dL for the women;APwasconsideredhighwhen≥375U/Lforinfants and100U/Lforthewomen.9

Theanalysis wasperformed usingtheIBM® _SPSS®

soft-ware,release20.0forWindows(SPSS,Chicago,IL,USA)and STATA version9.1(Stata Corp.,CollegeStation,TX, USA). The Kolmogorov---Smirnovtest wasusedtoassess the nor-mality ofthe quantitativevariables. Categorical variables were analyzed using Poisson regression and asmagnitude measure, we used the prevalence ratio (PR) and their respective95%confidenceintervals(95%CI)toevaluate non-sufficiency of VD. Spearman’s correlation was calculated between25(OH)DandthevariablesAP,PTH,CaandPofthe womenandnewborns.Mann---Whitneytestwasusedto com-parethelevelsofCa,PTH,25(OH)D,PandAPbetweenthe womenandinfantswithVDsufficiencyandnon-sufficiency. Multiple linear regression analysis was performed to identifyfactors associatedwith25(OH)D deficiencyin the newbornsandthewomenparticipatinginthestudy.The cri-teriondefinedforinclusionofvariablesinthemultiplelinear regressionwastheassociationwiththedependentvariable atthesimplelinearregressionanalysis,consideringavalue ofp<0.20.Statisticalsignificancelevelwassetat˛<5%.

Results

Of the 226 mothers and their newborns assessed in the

study, 200 women (88.5%) were aged between 20 and 44

years (mean 28 years),and 26 (11.5%) were adolescents.

Regardingethnicity,118(52.2%)womenreportedbeing

Cau-casian. It is noteworthy that 62 (43.5%) participants had

8 years or less of schooling, 192 (85%)lived in the urban

areaand176(77.9%)livedwithapartner.Itwasobserved

that 152 (67.3%) had more than one child. Regarding the

type of delivery, 179 (79.2%) underwent a cesarean

sec-tion.Duringpregnancy,142(97.3%)womenreportedtaking

a multivitamin supplement, 79 (54.1%) did not meet the

sunexposurerecommendationsand91(40.3%)reportednot

usingsunscreen.Therewasnoassociation(p>0.05)between

thelevelsof25(OH)Didentifiedinthewomenandage,

eth-nicity,schooling,maritalstatus,parity,placeofresidence,

typeofdelivery,vitaminsupplementintake,sunlight

expo-sureoruseofsunscreens.

Of the newborns, 117 (51.8%) were females and 119

(52.7%) were Caucasian. The infants’ mean gestational

age and weight were 38.7±1.0 weeks and 3248±446g,

respectively;theinfants’lengthwas48.8±2.1cm,andhead

circumference was 33.9±1.5cm. There was no

associa-tion between the infants’ levels of 25(OH)D and gender,

ethnicity,seasonoftheyear,weight,lengthandhead

cir-cumferenceorgestationalage.

TherewasnodifferenceinthelevelsofCa,AP,PandPTH

betweenthewomenwithVDsufficiencyandnon-sufficiency

differ-itamin

D

deficiency

prevalence

in

women

and

newborns

289

Table1 Biochemicalparametersofwomenandtheirnewbornsclassifiedaccordingtothesufficiencyornotof25(OH)Dinthepostpartumperiod.

Women Newborns

Non-sufficiency Sufficiency Non-sufficiency Sufficiency

n(%) Inadequacy

Mean (SD)

Median (min---max)

Mean (SD)

Median (min---max)

p-value n(%) Inadequacy

Mean (SD)

Median (min---max)

Mean (SD)

Median (min---max)

p-value

APU/L 100(84.2)↑ 102.3(2.5) 98.0(34---232) 92.3(6.9) 80.0(42---187) 0.06 44(19.5)↓ 108.2(2.8) 104.0(48---290) 113.8(7.3) 107.0(40---236) 0.57 CAmg/dL 34(15.5)↓ 9.4(0.1) 9.0(4---11) 9.3(0.1) 9.0(8---11) 0.55 8(3.5)↓ 10.1(0.1) 10.0(8---12) 9.8(0.1) 10.0(8---11) 0.03 Pmg/dL 06(2.7)↑ 13.8(0.7) 4.0(2---6) 13.7(1.4) 4.0(3---30) 0.86 7(3.1)↓ 2.4(0.3) 5.0(3---7) 2.5(0.5) 5.0(3---7) 0.92 PTHpicog/mL --- 3.9(0.04) 12.0(1---67) 4.0(0.2) 12.0(3---30) 0.74 190(84.2)↓ 4.7(0.1) 1.0(1---28) 4.7(0.1) 1.0(1---14) 0.62 25(OH)Dng/mL 192(85) 21.1(0.4) 22.0(8---30) 35.0(0.9) 33.0(30---50) <0.001 182(80.5) 21.4(0.4) 22.0(8---30) 34.7(0.6) 34.0(30---48) <0.001

290 M.R.M.C.doPradoetal.

Table2 Possiblefactorsassociatedwithnon-sufficiencyofvitaminDinwomeninthepostpartumperiod.

Non-sufficiencyc _{Sufficiency PR(95%CI) p}a

n % n %

Seasonoftheyear

Fall 42 21.9 9 26.5 1 0.40

Otherseasons 150 78.1 25 73.5 0.95(0.87---1.05)

Ethnicity

Caucasian 100 52.1 18 52.9 1 0.92

Non-Caucasian 92 47.9 16 47.1 1.00(0.90---1.12)

Sunlightexposureduringpregnancyb

Yes 41 37.5 4 16.0 1 0.054

No 80 62.5 21 84.0 1.10(0.99---1.22)

Multivitaminsupplementsb

Yes 120 97.6 22 95.7 1 0.68

No 3 2.4 1 4.3 0.88(0.50---1.57)

Placeofresidence

Rural 32 16.7 2 5.9 1 0.14

Urban 160 83.3 32 94.1 0.35(0.08---1.40)

Sunscreenprotectioninpregnancyb

Yes 47 38.2 8 34.8 1 0.75

No 76 61.8 15 65.2 0.97(0.84---1.12)

PRprevalenceratio;95%CI,confidenceinterval. a_{Poissonregression.}

b _{n=146womenanswered.}

c _{Non-sufficiency(deficiency+insufficiencyofvitaminD).}

enceregardingthelevelsofAP,PandPTHbetweeninfants

withVDsufficiencyandnon-sufficiency(Table1).

VDD occurred in 61 women (27%) and 66 newborns (29.2%); 131 women (58%) and 116 infants (51.3%) had VDinsufficiency, andonly 34women(15%) and44(19.5%) newborns showed VD sufficiency. Severe VDD (VD lev-els≤0ng/mL) was observed in 15 women (11.9%) and 4 newborns(1.8%).

TherewasnoassociationbetweenVDnon-sufficiencyin womenorthenewborns andseasonoftheyear,ethnicity, placeofresidence,sunlight exposure,useofmultivitamin supplementandsunscreenuse(Tables2and3).

When performing the multiple regression analysis to estimatetheinfluenceofobstetric,biologicaland socioeco-nomicvariablesinrelationtothemothers’VDD,variables withp≤0.20wereincludedinthemodel:maternal school-ing(p=0.02),placeofresidence(p=0.11),sunlightexposure (p=0.16)andABEPclassification(p=0.04).Inthefinalmodel, there was no statistically significant association of these variableswithmaternalVDD.

Whenperformingthemultivariateregressiontoestimate theinfluenceofthesevariablesinrelationtothenewborns’ VDD, variables withp≤0.20 were included in the model: seasonof birth (p=0.06), NB ethnicity(p=0.19), maternal 25(OH)D (p<0.001) NB Ca (p=0.15) and maternal alkaline phosphatase(p=0.0).Maternallevelsof25(OH)Dand alka-linephosphatasebehavedasindependentpredictorsofVDD inthenewborns(Table4).Thismodelaccountedfor58%of thevariationinVDlevelsofthenewborns(Table4).

When using Spearman’s correlation, we observed an association between PTH and 25(OH)D of the newborns

(r=−0.142; p=0.033; R2_{=0.006), with a strong association}

betweenmaternalandnewbornlevelsof25(OH)D(r=0.73; p<0.0001;R2_=0.558).

Discussion

VitaminDdeficiencyis aworldwidepublichealthproblem

andBrazilispartofthisscenario,withahighprevalenceof

VDD inthe population,asdemonstratedbystudies at

dif-ferent age groups.20 _{However, no studies have evaluated}

maternal and NB VDD as the present study. We found a high prevalence of VD insufficiency, of 80.5% and 85% in newborns andwomen,respectively, although97.3%of the womenreportedtheuseofmultivitaminsupplementsduring pregnancy. In India, 66.7% of VDD was found in the chil-drenand81.1%inthemothers.InKorea,18%oftheinfants had VDD and 73.6% had VD insufficiency at birth. In the USA, rates of 22.3% of VDD and 73.6% of VD insufficiency wereidentifiedin290babies,andVDinsufficiencywasalso identifiedinseveralcountries.8---11,13,21_Reportsinthe liter-aturehave shownthatthelackof orinadequateexposure tosunlightwithout adequatecorrective VDintakeor vita-min supplementscan explain the high VDD prevalence in women.1,8

Table3 Possiblefactorsassociatedwithnon-sufficiencyofvitaminDinthenewborns.

Non-sufficiencyc _{Sufficiency PR(95%CI) p}a

n % n %

Seasonoftheyear

Fall 37 20.3 14 31.8 1 0.42

Otherseasons 145 79.7 30 68.2 0.96(0.88---1.05)

Ethnicity

Caucasian 96 52.7 23 52.3 1 0.95

Non-Caucasian 86 47.3 21 47.7 0.99(072---1.35)

Sunlightexposureduringpregnancyb

Yes 58 45.5 9 37.5 1 0.36

No 64 52.5 15 62.5 0.93(0.81---1.07)

Multivitaminsupplementsb

Yes 119 97.5 23 95.8 1 0.70

No 3 2.5 1 4.2 0.89(0.50---1.58)

Placeofresidence

Rural 28 15.4 6 13.6 1 0.77

Urban 154 84.6 38 86.4 0.88(0.39---2.00)

Sunscreenprotectioninpregnancyb

Yes 45 36.9 10 41.7 1 0.66

No 77 66.1 14 58.3 1.03(0.88---1.20)

PRprevalenceratio;95%CI,confidenceinterval. a _{Poissonregression.}

b _{n=146womenanswered.}

c _{Non-sufficiency(deficiency+insufficiencyofvitaminD).}

area,skinpigmentation,sunscreenuse,timeofthedayof

exposure,season,latitude,altitudeandairpollution.2

An increasein thesun’szenithangle duringthe winter and in the early morning and late afternoon results in a longerpathforUVBraystogothroughtheozonelayerand beabsorbed.Thisexplainswhy,aboveandbelow33◦_of lat-itude,littleornoVDisproducedintheskinduringwinter. Thisalsoexplainswhythesynthesisandgreaterabsorption of VD occuronly between 10am and3pmat the equator or in places closer toit. Thus, sunlight exposure of arms andlegsfor5---30min,twiceaweek,from10amto3pm,is adequate.17

The BrazilianSocietyofPediatricsadvisesthatchildren youngerthan6monthsshouldbeexposedtodirectsunlight fromthe 2nd week of life and that 30min/week wearing only diapers (6---8min a day, 3 times a week) or 2h/week withpartialexposure(17minaday),exposingthefaceand hands, are enough.22 _{The Brazilian Recommendations of} Endocrinology and Metabolism advise VD supplementation of600IU/dayforpregnantwomenand400IU/dayfor

chil-dren,frombirthtothefirstyearoflife,astheybelongto theriskgroupforVDD.20,23,24

Dark-skinnedindividualshavedifficultytoproduceVD.25 Thereisa greateraffinityof melanin,asthe melanocytes aremoreactiveandeasilyabsorbUVBrays,whichhinders theconversionof7-dehydrocholesterolmoleculeintoVD.A dark-skinnedindividualrequires10---50timesmoresunlight exposuretoproducethesameamountofVDincomparison tolight-skinned individuals.25 _{However,in this study, skin} colorshowednoassociationwithVDnon-sufficiency;similar resultswerefoundinstudiescarriedoutinGreeceandthe USA.10,21_{Regardingtheuseofsunscreen,aprotectionfactor} (SPF)of 15 reducesVD productioncapacity by morethan 98%,26_{althoughmostofthewomeninthestudywithVD} non-sufficiencyreportedtheyhadnotusedanytypeofsunscreen duringpregnancy.

There was an association between 25(OH)D levels of the women and the newborns. There is a strong associa-tionof circulatingVD levelsbetween themother andthe fetus, so that maternal VDD reflects in neonatal VDD,8,13

Table4 Multipleregressionanalysisforpredictorsofdeficiencyof25(OH)D(ng/mL)inthenewborns.

Variable VitaminDNewborn

Univariate Multivariate

ˇ p-value R2 _{ˇ p-value R}2

Maternal25(OH)D 0.73 <0.001 0.55 0.73 <0.001 0.58 Maternalalkalinephosphatase −0.029 0.024 0.022 −0.01 0.045

292 M.R.M.C.doPradoetal.

exposingchildrentotheriskofrickets.1_{Inpregnancy,the}

lowstatus or low intakeof VDis detrimental toboth the mother and the fetus and predisposes to VD deficiency in infancy.1 _{VDD in childhood has been associated with} increasedrisk of lowerrespiratory tract infections, while low VD plasma levels in cord blood were associated with increasedriskofacuterespiratoryinfectionsandwheezing inchildhood.13

Itis noteworthy that44.2% (100)of thewomen inthis studyhadhighAPlevels,whichsuggestsosteoblasticactivity orbonemobilizationofCaandPtomeetthehigh require-mentsof thefetus. Inthepresenceof mineraldeficiency, thereisincreasedAPsynthesis.27

Thereweredifferencesinthelevelsof25(OH)Dof new-bornswithnon-sufficiencyandsufficiencyofVDandcalcium. In the diagnosis of rickets, some of the following tests are altered: serum CA, P, PTH, 25(OH)D or AP.28 _{This is} characterized as an important result, as 66 infants had VDD, four had severe 25(OH)D deficiency, with VD levels ≤10ng/mL and eight had hypocalcemia. Severe hypocal-cemiawithor without seizures is acommoncomplication of VDD in the neonatalperiod or early childhood, due to thematernalVDD,alongwithinadequateintakeofVDfrom breastmilkorsupplements.Thisconditioncanbeprevented throughadequate levelsofmaternal VD duringpregnancy andsupplementationininfancy.1_{Inthisstudy,PTHlevelsin} cordblood of84.2%of theinfantswerebelowthenormal level.Itissuggestedthatthisfactisaconsequenceofhigh Caconcentrationsthatexistduringthisperiod(suppliedby maternalCa),5,29 _{without theneedtostimulatePTH} func-tionofthenewbornsasasecondarymechanismofCaandP mobilizationfrombone,whichare,therefore,physiological mechanisms.

Thisstudyhaslimitationsduetoitscross-sectionaldesign andalsobecausesomeriskfactors,suchassunscreenuse, use of multivitamin supplements and amount of time of sun exposure during pregnancy can generate recall bias, astheyareself-reportedinformation.However,theresults obtained in this study can be used in other studies and in other populations, especially in Latin America, where theyarescarce, asthe assessedsample consisted of ran-domly selectedindividuals fromthe target population, so thatthesamplewasrepresentativeofthepopulation. More-over,VDDisaworldwideproblemthroughoutthelifecycle. Itissuggestedthatfurtherstudiesbecarriedouttobetter understandthedeterminantsofVDlevelsinother popula-tiongroups.

Although Brazilisa tropicalcountry,where VDDis less likelytooccurthanincountrieslocatedfarfromthe equa-tor,ahighprevalenceofVDnon-sufficiencywasidentifiedin thispopulationofwomenandnewborns,whichcanbe pre-ventedby providingguidelinesfor womenduringprenatal careandthepostpartumperiodinrelationtosunexposure andVDsupplementation.Itwasfoundthattheriskfactors thatcontributedtothelowlevelsofVDinnewbornswere maternal25(OH)DandAPlevels.Otherriskfactors,namely season,ethnicity,placeofresidence,sunexposure,useof multivitaminsupplementsanduse ofsunscreen, werenot associatedwithVDDinwomenandnewborns.Therefore,the importanceofassessingthenutritionalstatusofVDduring motherandchildroutinecareisnoteworthy.

Funding

FAPEMIG --- Fundac¸ão de Amparo à Pesquisa do Estado de

Minas Gerais, Process n. APQ 00846-11-Edital 01/2011

---DemandaUniversal.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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