Vi­ta­min D de­fi­ciency is widely over­es­ti­mated, doc­tors warn

Not the ‘we need more’ news

Kuwait Times - - HEALTH -

NEW YORK: Doc­tors are warn­ing about vi­ta­min D again, and it’s not the “we need more” news you might ex­pect. In­stead, they say there’s too much need­less test­ing and too many peo­ple tak­ing too many pills for a problem that few peo­ple truly have.

The nu­tri­ent is cru­cial for strong bones and may play a role in other health con­di­tions, though that is far less cer­tain. Mis­un­der­stand­ings about the rec­om­mended amount of vi­ta­min D have led to mis­in­ter­pre­ta­tion of blood tests and many peo­ple think­ing they need more than they re­ally do, some ex­perts who helped set the lev­els write in Thurs­day’s New Eng­land Jour­nal of Medicine .

Cor­rectly in­ter­preted, less than 6 per­cent of Amer­i­cans ages 1 to 70 are de­fi­cient and only 13 per­cent are in dan­ger of not get­ting enough. That’s con­cern­ing, “but these lev­els of de­fi­ciency do not con­sti­tute a pan­demic,” the au­thors write. Yet peo­ple may think there is one. Blood tests for vi­ta­min D lev­els not ad­vised un­less a problem like bone loss is sus­pected - are soar­ing. Un­der Medi­care, there was an 83-fold in­crease from 2000 to 2010, to 8.7 mil­lion tests last year, at $40 apiece. It’s Medi­care’s fifth most com­mon test, just af­ter choles­terol lev­els and ahead of blood sugar, uri­nary tract in­fec­tions and prostate can­cer screen­ing. “I’m not sure when it got pop­u­lar to check every­body for vi­ta­min D de­fi­ciency,” but pa­tients of­ten ask for it, es­pe­cially baby boomers, said Dr. Kenny Lin, a Ge­orge­town University fam­ily physi­cian and pre­ven­tive medicine ex­pert.

Vi­ta­min D pill use also grew, from 5 per­cent of Amer­i­cans in 1999 to 19 per­cent in 2012.

Sug­ges­tive re­ports

That may be due to many re­ports sug­gest­ing harm from too lit­tle of “the sun­shine vi­ta­min,” called that be­cause our skin makes vi­ta­min D from sun ex­po­sure. It’s tough to get enough in win­ter or from di­etary sources like milk and oily fish, though many foods and drinks are for­ti­fied with vi­ta­min D and la­bels soon will have to carry that in­for­ma­tion. Too much vi­ta­min D can lead to high lev­els of cal­cium in the blood, which can cause nau­sea, con­sti­pa­tion, kid­ney stones, an ab­nor­mal heart rhythm and other prob­lems.

“We’re not say­ing that mod­er­ate-dose sup­ple­ments are risky, but more is not nec­es­sar­ily bet­ter,” said Dr. JoAnn Man­son of Brigham and Women’s Hos­pi­tal in Bos­ton. She and sev­eral other ad­vis­ers to the In­sti­tute of Medicine, which set the RDA, or rec­om­mended di­etary al­lowance, wrote the jour­nal ar­ti­cle. Peo­ple vary, bi­o­log­i­cally, in how much of any vi­ta­min they need. The in­sti­tute es­ti­mated this by com­par­ing var­i­ous in­take and blood lev­els with mea­sures of bone health. They es­ti­mated that, on av­er­age, peo­ple need about 400 in­ter­na­tional units of vi­ta­min D per day, and 600 for peo­ple over 70.

To be safe and en­sure that every­one gets enough, they set the RDA at the high end of the spec­trum of the pop­u­la­tion’s needs - 600 to 800 units, de­pend­ing on age. So by definition, nearly every­one’s true re­quire­ment is be­low that.

Many peo­ple and their doc­tors re­gard the RDA and its cor­re­spond­ing blood lev­els as a thresh­old that every­one needs to be above, the au­thors write. As a re­sult, peo­ple of­ten are told they are in­ad­e­quate or de­fi­cient in D when, in fact, they’re not. “If you’re chas­ing a lab num­ber, that will lead to many peo­ple get­ting higher amounts of vi­ta­min D than they need,” and labs vary a lot in the qual­ity of test­ing, Man­son said.

The bot­tom line: Get 600 to 800 units a day from food or sup­ple­ments and skip the blood test un­less you have spe­cial risk fac­tors, Man­son said. A big study she is help­ing lead is test­ing whether higher lev­els lower the risk of can­cer, heart dis­ease, stroke, mem­ory loss, de­pres­sion, di­a­betes, bone loss or other prob­lems. Nearly 26,000 peo­ple have been tak­ing 2,000 units of D-3 (the most ac­tive form of vi­ta­min D, also known as chole­cal­cif­erol) or dummy pills ev­ery day for five years. Re­sults are ex­pected in early 2018.—AP

NEW YORK: Vi­ta­min D pill bot­tle Nov 9, 2016. —AP

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