Note: It was widely reported on the internet in Oct 2012 that colds not stopped by vitamin D

   At the bottom of this page is a list of some of the titles reporting on this study - without reading it.''

Effect of Vitamin D3 Supplementation on Upper Respiratory Tract Infections in Healthy Adults

The VIDARIS Randomized Controlled Trial

JAMA. 2012;308(13):1333-1339. doi:10.1001/jama.2012.12505.
David R. Murdoch, MD; Sandy Slow, PhD; Stephen T. Chambers, MD; Lance C. Jennings, PhD; Alistair W. Stewart, BSc; Patricia C. Priest, DPhil; Christopher M. Florkowski, MD; John H. Livesey, PhD; Carlos A. Camargo, MD; Robert Scragg, PhD
Department of Pathology, University of Otago, Christchurch (Drs Murdoch, Slow, Chambers, Jennings, and Florkowski),
Canterbury Health Laboratories (Drs Murdoch, Jennings, Florkowski, and Livesey), and
Department of Infectious Diseases, Christchurch Hospital (Dr Chambers), Christchurch, New Zealand;
School of Population Health, University of Auckland, Auckland, New Zealand (Mr Stewart and Dr Scragg);
Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (Dr Priest); and
Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (Dr Camargo).

Context Observational studies have reported an inverse association between serum 25-hydroxyvitamin D (25-OHD) levels and incidence of upper respiratory tract infections (URTIs). However, results of clinical trials of vitamin D supplementation have been inconclusive.

Objective To determine the effect of vitamin D supplementation on incidence and severity of URTIs in healthy adults.

Design, Setting, and Participants Randomized, double-blind, placebo-controlled trial conducted among 322 healthy adults between February 2010 and November 2011 in Christchurch, New Zealand.

Intervention Participants were randomly assigned to receive an initial dose of 200 000 IU oral vitamin D3, then 200 000 IU 1 month later, then 100 000 IU monthly (n = 161), or placebo administered in an identical dosing regimen (n = 161), for a total of 18 months.

Main Outcome Measures The primary end point was number of URTI episodes. Secondary end points were duration of URTI episodes, severity of URTI episodes, and number of days of missed work due to URTI episodes.

Results The mean baseline 25-OHD level of participants was 29 (SD, 9) ng/mL. Vitamin D supplementation resulted in an increase in serum 25-OHD levels that was maintained at greater than 48 ng/mL throughout the study.

There were 593 URTI episodes in the vitamin D group and 611 in the placebo group, with

• no statistically significant differences in the number of URTIs per participant (mean, 3.7 per person in the vitamin D group and
• 3.8 per person in the placebo group; risk ratio, 0.97; 95% CI, 0.85-1.11),
• number of days of missed work as a result of URTIs (mean, 0.76 days in each group; risk ratio, 1.03; 95% CI, 0.81-1.30),
• duration of symptoms per episode (mean, 12 days in each group; risk ratio, 0.96; 95% CI, 0.73-1.25), or severity of URTI episodes.

These findings remained unchanged when the analysis was repeated by season and by baseline 25-OHD levels.

Conclusion In this trial, monthly administration of 100 000 IU of vitamin D did not reduce the incidence or severity of URTIs in healthy adults.

– – – – – – – – – –

Observation by VitaminDWiki

Both groups started with an adequate amount of vitamin D: 30 ng/ml

Note! 80% of Australia probably has < 30 ng/ml
Vitamin D would probably have helped prevent colds/flu in the 80% of Australia which have low levels of vitamin D
Suspect that this study just took students and staff who were healthy, were white (95%), fit, only 5% smoked, and did not have diabetes (2%)
  thus ignoring the Australian's who were at high risk of being vitamin D deficient, due to:
    : dark skin, overweight, elderly, pregnant, recovering from surgery, digestive problems, etc.

CLICK HERE for JAMA article and perhaps PDF

(After trying 7 times, have been unable to download the PDF even once)

See also VitaminDWiki

• Common cold (Acute Rhinosinusitis) 12 percent more likely for every 10 nanogram lower Vitamin D – Oct 2015
• Reduction in Cold and Flu with Vitamin D
• All items in category Immunity and Vitamin D 262 items
• Prevent colds and flu with vitamin D
• All items in category Aust/NZ and Vitamin D 68 items
• 3X more colds by overweight who were low on vitamin D - April 2012
• An update on vitamin D and human immunity – March 2012
• Why randomized controlled trials of calcium and vitamin D sometimes fail – June 2012

Reduced viral respiratory track infections by half by having more than 38 ng of vitamin D – June 2010 which has the following chart

Take vitamin D3 daily or weekly

has the following notional chart shows decrease in vitamin D benefits with monthly dosing at 50 ng

Half-life of vitamin D varies has the following chart

Reduce probability of getting the Flu

which has the following chart: 800 IU and 2,000 IU reduces flu

See also web

• The Common Cold Foundation for better Health Care Oct 2012
  Note: the above study participants were healthy - having less than the average
  Adults average about two to four colds a year, although the range varies widely.
  Women, especially those aged 20 to 30 years, have more colds than men, possibly because of their closer contact with children
  More than 200 different viruses are known to cause the symptoms of the common cold
• Common cold - Patient friendly summary Vitamin D Council
  In one study, vitamin D levels of 38 ng/mL were needed to significantly lower the risk of upper respiratory infections including colds.
  The risk of the common cold and influenza was studied in postmenopausal African-American women.
    Women taking 2000 IU of vitamin D3 had a 90% reduction in either disorder.
• Vitamin D Council review of this RCT
  With many personal comments by readers about having no colds when have lots of vitamin D
• Will Boosting Your Vitamin D Levels Help Prevent Colds or Not? Mercola and Vitamin D Council discuss this study
• Don't Leave Vitamin D Out in the Cold This Winter Huffington post comment on same RCT]

The titles of some of the articles announcing (but not reading) this study

Vitamin D Does Not Help Prevent Colds
Extra Vitamin D May Not Help Ward Off Colds
'No proof' vitamin D stops colds
Extra vitamin D may not help ward off colds
Vitamin D Does Not Prevent Colds
Vitamin D gets an 'F' on cold prevention: study
Vitamin D Won't Save You From Common Cold, Latest Study Says
Does Vitamin D Help Stop Colds?
JAMA Study Finds Vitamin D Doesn't Reduce Colds
Vitamin D No Help For Colds
Vitamin D Doesn't Fight Off Colds
Vitamin D won't keep the doctor away - study
Vitamin D No Match for Common Cold
Vitamin D may do nothing to prevent common colds
Extra vitamin D may not help ward off colds
Trying to Avoid a Cold? Skip the Vitamin D Supplements
Strike Vitamin D Off the List for Cold Prevention?
'No proof' vitamin D stops colds
Vitamin D Won't Save You From Common Cold, Latest Study Says
Vitamin D supplements no help for colds, flu
Vitamin D No Help For Colds, Study Suggests
Caught a cold? Don't bother taking vitamin D - scientists say no evidence ...
Vitamin D doesn't do much for common colds, study says
Vitamin D pills don't prevent colds
Vitamin D supplements may not cure cold
Vitamin D Will Not Help Fight or Prevent Your Cold
Vitamin D pills show no common cold benefits for people with sufficient vitamin ...
Vitamin D Supplement Not Helpful in Avoiding Colds
Vitamin D gets an 'F' on cold prevention: study
Vitamin D pills do not protect against common cold, study suggests
Vitamin D supplements unlikely to reduce risk of colds
Vitamin D does not cure severe cold
Vitamin D supplements don't help colds, flu
Vitamin D No Help For Colds
Study finds vitamin D supplements do not prevent colds
Does Vitamin D Help Stop Colds?