Vitamin D Supplements Don't Prevent Respiratory Infections

Summary and Comment |
November 21, 2013

Vitamin D Supplements Don't Prevent Respiratory Infections

  1. Abigail Zuger, MD

Occurrence and duration of colds and flu-like illness were unaffected by oral supplementation.

  1. Abigail Zuger, MD

Vitamin D deficiency has been associated with many medical problems, but whether repletion improves clinical outcomes is still largely unclear. U.S. researchers who were conducting a large blinded trial of vitamin D3 and calcium supplementation for preventing large bowel adenomas included a substudy to look at rates of upper respiratory tract infection among participants.

Participants were healthy adults (age range, 45–75) whose initial vitamin D levels exceeded 12 ng/mL. During a period that spanned two winter “flu seasons,” 399 participants who were receiving daily vitamin D (1000 mg) and 360 participants who were receiving placebo reported identical rates of both serious and trivial upper respiratory infections. These results were unaffected by adjustment for receipt of supplemental calcium, receipt of flu vaccine, or body-mass index. Rates were similar during the first winter of the study, which overlapped the H1N1 flu pandemic (2009–2010), and during the subsequent one without pandemic influenza. Mean serum vitamin D levels did not differ among participants who did and did not report respiratory illnesses.


This study joins others in suggesting that supplemental vitamin D doesn't prevent respiratory infections — at least in people without severe vitamin D deficiencies.

Editor Disclosures at Time of Publication

  • Disclosures for Abigail Zuger, MD at time of publication Editorial boards Journal Watch AIDS Clinical Care; Clinical Infectious Diseases Other New York Times medical writer


Reader Comments (5)

Clara A. Lennox, MD Physician, Family Medicine/General Practice, Melrose, MA

1000 IU daily of Vitamin D is not enough of a dose for an adult to attain a blood level sufficient for benefits to be observed.

Brian Seitz Other Healthcare Professional, Other

First of all, it is 1000 IU not 1000 mg. This study does not show that D3 supplementation does not prevent URI. It shows that 1000 IU daily has no appreciable effect, which would make sense because if the individuals are insufficient 1000 IU will not normalize their levels. Below 32 ng/mL is insufficient. According to many experts we should shoot for 50 ng/mLTerrible study, terrible summary on your part!

albert einstein associate degree retired

any vit d level below 40ng/dl is worthless for immune stimilation.pimping for the vaccine companies her doktor?

Jon Sterngold MD Physician, Preventive Medicine, Santa Rosa, CA

Once again, a low dose of D3, one that cannot raise levels to a protective range, has no effect. Gee.....

Laver Stroka Physician, Family Medicine/General Practice, Gjirokastra, Albania

Dear Ser / Madam !
During a 30 -year period that I have given as prophylaxis in children 0-12 months 300 000 UI vitamin D I.M. after the third week of the first month of life and in the month of 3,5,7,9 and 11 . Applying of mouth did not provide the same benefits when it has been proven in a limited contingent for limited period .
Application I.M. helped normal psychomotor development , skeletal and in the prevention of convulsions afebrile and sudden deaths . Respiratory infections in this sample have been very limited compared to other children attend other clinics where it is not applied Vitamin D IM , but only from the mouth and rarely .
When children have come with rickets or spasmophilia or resistant pulmonary infections treated with various antibiotics , I have applied of 600 000 UI vitamin D in two first months following the arrival besides other treatment .
The antibiotics are substituted with TMP - SMZ , propol , onion juice on resistant pulmonary infections. The child condition is improved rapidly.
Laver Stroka , MD . Gjirokastra, Albania

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