Vitamin D may do nothing to prevent common colds

If you're looking for a surefire way to prevent a common cold, you may have to wait a bit longer. A new study finds one previously trusted remedy -- a dose of vitamin D -- does nothing to ward off the sniffles.

Adults catch on average two to four colds a year, and children contract up to 10, according to the BBC. Previous experiments have shown that vitamin D may be able to give a boost to the immune system and other studies have shown that people with low levels of vitamin D were more likely to develop colds or other forms of upper respiratory tract infections (URTIs).

Researchers in New Zealand tested out the vitamin D theory in an 18-month study. A group of 322 healthy adults were told either to take a vitamin D supplement or a placebo. Those who took the vitamin were given 200,000 international units (IU) each month or about 6,600 units a day for two months and 100,000 IU once a month or about 3,300 daily for the rest of the study. The Institute of Medicine of the National Academies in Washington D.C. recommends that people under 70 consume 600 IU of vitamin D daily, and people over 70 years take 800 IU daily.

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The participants were asked to call researchers if they had symptoms of a common cold like runny nose or sneezing. Swabs were taken to determine if they had the cold virus.

At the end of the study there were 593 episodes of respiratory infections -- on average 3.7 colds per person -- in the vitamin D group and 611 episodes -- on average 3.8 colds per person -- in the placebo group. Each group averaged 12 missed days of work because of their illness. Statistically speaking, there was no real difference in cold risk between vitamin D and placebo pills when chance is taken into consideration.

"The main finding from this study is that a monthly dose of 100,000 IU of vitamin D3 in healthy adults did not significantly reduce the incidence or severity of URTIs. This result remained unchanged when the analysis included winter season or baseline [vitamin D] levels," the authors wrote.

Dr. Jeffrey Linder, assistant professor at Harvard Medical School and an internal medicine specialist at Brigham and Women's Hospital in Boston, said in an accompanying editorial that vitamin D should be added to the Cochrane Collaboration's registry of ineffective, possibly harmful common cold remedies. The list includes Chinese herbs, intranasal corticosteroids, asthma drug intranasal ipratroprium, extract of South African plant Pelargonium sidoides, nasal irrigation, extra fluid intake, Echinacea, zinc, steam inhalation, vitamin C, garlic, antihistamines, or antiviral drugs.

But Ronald Eccles, director of the Common Cold Center and professor at Cardiff School of Biosciences at Cardiff University in Cardiff, Wales, told the BBC that it doesn't necessarily mean that Vitamin D can't help you. He said it helps boost the immune system especially during the winter season, and he personally takes it every year to help ward of illness.

"There is sufficient information to indicate that vitamin D is a vital vitamin for the immune system," he said.

The study was published in the Oct. 2 issue of the Journal of the American Medical Association.

[Bootski59]

Ok, this study is stupid. Pure Vitamin D3 will definitely ward off colds and flu. I'm 59 years old. I would get 2 to 3 colds every single year without fail. My cold would last 30 days or more. I was always sick in the winter. I started taking good pure natural vitamins and I was down to one cold a year. I could never ever get through a winter without at least one bad cold. Last winter, I tried something different. I took 2,000IU's Vitamin D3 each day, and it was the first winter in all my 59 years that I did not catch a cold or flu. I'm coming up to another winter and I will do the same thing, and see what happens. I know vitamin D3 got me through last winter and the summer too. I feel great!! Don't let this stupid study stop you from being healthy. A good natural brand of vitamin D3, capsules, 1,000 to 2,000 IU a day will keep you healthy. Take a good raw multi vitamin with it. Always get your Vitamin D tested when you get a blood test.

[cny_ap]

I wonder if they bothered to measure their blood levels to see how much vitamin D were in the two groups' blood.

I was going to say EXACTLY the same thing. I was sick on and off (mostly on) with nuisance colds for 5-6 months a year for ~10 years. I can't recall why, but I started taking vitamin D, and a few months later noticed I had not been sick. I can't remember if I took it thinking it might reduce my constant colds. Since I started taking it 3-4 years ago, I rarely catch colds, and when I do, they are not as long lasting or severe. I am very healthy - low blood pressure, exercise quite a bit; etc. We get very little sun here in the winter, most of us are low on vitamin D, and doctors believe it might explain the high MS rates in cloudy northern areas.

[eroteme2]

May do nothing? Of course. But this means they also may do something.

[Ehra_L]

you people sure its not Vitamin C?

[dcolley2]

Wonder which big company paid for this survey. Stop taking this and buy our product instead.

[YuliaStore]

Hypothetically Vitamin D was linked to multiple sclerosis but not enough evidence. I would suggest taking transfer factor to get rid of colds, congestion allergies etc.
www.yuliastore.com

[Shadeymilkman449]

Breaking news: Eating well balanced foods, exercise, and engaging oneself into society (which should get you into the sun long enough to produce vitamin D) leads to healthier life.

In other breaking news...sitting in basement eating Cheetos all day may lead to Autism
Cancer (various types)
Chronic Liver Disease (Cirrhosis)
Crohn's Disease
Depression
Diabetes
Heart Disease
High Blood Pressure
Inflammatory Bowel Disease (IBD)
Obesity
Osteoporosis
Overall Lifespan
Various Skin Conditions (Including Psoriasis)

Learn more at commonsense.com

[cny_ap]

Do you go outside with skin exposed where it's below freezing 4-5 months of the year? Areas around the Great Lakes are cloudy, cold, and have have MS rates.

[Puristat_Wellness_Center]

Vitamin D deficiency has been linked to:

Autism
Cancer (various types)
Chronic Liver Disease (Cirrhosis)
Crohn's Disease
Depression
Diabetes
Heart Disease
High Blood Pressure
Inflammatory Bowel Disease (IBD)
Obesity
Osteoporosis
Overall Lifespan
Various Skin Conditions (Including Psoriasis)

Researchers at Montreal's McGill University report that every cell in the human body has receptors for vitamin D; they speculate that hundreds of different genes may be regulated by it.

Learn More at The Puristat Digestive Wellness Center (online)