ExtraVitaminDandCalciumAren.docx

ExtraVitaminDandCalciumAren.docx

《ExtraVitaminDandCalciumAren.docx》由会员分享，可在线阅读，更多相关《ExtraVitaminDandCalciumAren.docx（4页珍藏版）》请在冰豆网上搜索。

ExtraVitaminDandCalciumAren

Extra-Vitamin-D-and-Calcium-Aren

ExtraVitaminDandCalciumAren’tNeeded,ReportSays

ByGINAKOLATA

Published:

November29,2010

TheveryhighlevelsofvitaminDthatareoftenrecommendedbydoctorsandtestinglaboratories—andcanbeachievedonlybytakingsupplements—areunnecessaryandcouldbeharmful,anexpertcommitteesays.Italsoconcludesthatcalciumsupplementsarenotneeded.

LawrenceLool/EuropeanPressphotoAgency

AvitaminDpill.

Readers'Comments

Shareyourthoughts.

PostaComment»

ReadAllComments（20）»

ThegroupsaidmostpeoplehaveadequateamountsofvitaminDintheirbloodsuppliedbytheirdietsandnaturalsourceslikesunshine,thecommitteesaysinareportthatistobereleasedonTuesday.

“Formostpeople,takingextracalciumandvitaminDsupplementsisnotindicated,”saidDr.CliffordJ.Rosen,amemberofthepanelandanosteoporosisexpertattheMaineMedicalCenterResearchInstitute.

Dr.J.ChristopherGallagher,directorofthebonemetabolismunitattheCreightonUniversitySchoolofMedicineinOmaha,Neb.,agreed,adding,“TheonusisonthepeoplewhoproposeextracalciumandvitaminDtoshowitissafebeforetheypushitonpeople.”

Overthepastfewyears,theideathatnearlyeveryoneneedsextracalciumandvitaminD—especiallyvitaminD—hassweptthenation.

Withcalcium,adolescentgirlsmaybetheonlygroupthatisgettingtoolittle,thepanelfound.Olderwomen,ontheotherhand,maytaketoomuch,puttingthemselvesatriskforkidneystones.Andthereisevidencethatexcesscalciumcanincreasetheriskofheartdisease,thegroupwrote.

AsforvitaminD,someprominentdoctorshavesaidthatmostpeopleneedsupplementsortheywillbeatincreasedriskforawidevarietyofillnesses,includingheartdisease,cancerandautoimmunediseases.

AndthesedaysmoreandmorepeopleknowtheirvitaminDlevelsbecausetheyarebeingtestedforitaspartofroutinephysicalexams.

“ThenumberofvitaminDtestshasexploded,”saidDennisBlack,areviewerofthereportwhoisaprofessorofepidemiologyandbiostatisticsattheUniversityofCalifornia,SanFrancisco.

Atthesametime,vitaminDsaleshavesoared,growingfasterthanthoseofanysupplement,accordingtoTheNutritionBusinessJournal.Salesrose82percentfrom2008to2009,reaching$430million.“EveryonewashopingvitaminDwouldbekindofapanacea,”Dr.Blacksaid.Thereport,headded,mightquellthecraze.

“Ithinkthiswillhaveanimpactonalotofprimarycareproviders,”hesaid.

The14-memberexpertcommitteewasconvenedbytheInstituteofMedicine,anindependentnonprofitscientificbody,attherequestoftheUnitedStatesandCanadiangovernments.Itwasaskedtoexaminetheavailabledata—nearly1,000publications—todeterminehowmuchvitaminDandcalciumpeopleweregetting,howmuchwasneededforoptimalhealthandhowmuchwastoomuch.

Thetwonutrientsworktogetherforbonehealth.

Bonehealth,though,isonlyoneofthebenefitsthathavebeenattributedtovitaminD,andthereisnotenoughgoodevidencetosupportmostotherclaims,thecommitteesaid.

Somelabshavestartedreportinglevelsoflessthan30nanogramsofvitaminDpermilliliterofbloodasadeficiency.Withthatasastandard,80percentofthepopulationwouldbedeemeddeficientofvitaminD,Dr.Rosensaid.Mostpeopleneedtotakesupplementstoreachlevelsabove30nanogramspermilliliter,headded.

But,thecommitteeconcluded,alevelof20to30nanogramsisallthatisneededforbonehealth,andnearlyeveryoneisinthatrange.

VitaminDisbeingaddedtomoreandmorefoods,saidPaulR.ThomasoftheOfficeofDietarySupplementsattheNationalInstitutesofHealth.Notonlyisitinorangejuiceandmilk,butmoreisbeingaddedtobreakfastcereals,anditnowcanbefoundinveryhighdosesinsupplementpills.MostvitaminDpills,hesaid,usedtocontainnomorethan1,000internationalunitsofit.Nowitiseasytofindpills,eveninplaceslikeWal-Mart,with5,000internationalunits.Thecommittee,though,saidpeopleneedonly600internationalunitsaday.

ToassesstheamountsofvitaminDandcalciumpeoplearegetting,thepanellookedatnationaldataondiets.Mostpeople,theyconcluded,getenoughcalciumfromthefoodstheyeat,about1,000milligramsadayformostadults（1,200forwomenages51to70）.

VitaminDismorecomplicated,thegroupsaid.Ingeneral,mostpeoplearenotgettingenoughvitaminDfromtheirdiets,buttheyhaveenoughofthevitaminintheirblood,probablybecausetheyarealsomakingitnaturallyafterbeingoutinthesunandstoringitintheirbodies.

TheAmericanSocietyforBoneandMineralResearchandothergroupsapplaudedthereport.Itis“averybalancedsetofrecommendations,”saidDr.SundeepKhosla,aMayoClinic