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Vitamin D & Flu Prevention

Written by: Dr. Loreen Dawson, ND

Supplementing with Vitamin D is one of the most effective and inexpensive ways to reduce your risk of getting colds and flu.  Vitamin D supplements prevent colds and flu in seniors, adults and children.

An American study of postmenopausal women, found a 60% reduction in colds and flu in women who took 800iu of vitamin D per day and a 90% reduction in those taking 2000iu per day.  To put this into perspective, the average effectiveness of flu vaccine is a 64% reduction in influenza compared to those who don’t get vaccinated.

A British study showed that adults with optimal levels of vitamin D had fewer respiratory infections and better lung function than adults with low levels of vitamin D.

Vitamin D supplements also benefit children.  A study of Japanese school children showed that those taking 1200iu vitamin D per day had significantly less influenza A than those who did not take vitamin D.  In addition, those children who had asthma had far fewer asthma attacks when taking vitamin D.

For most adults, supplementing 2000iu of vitamin D per day is a safe and effective way to reduce their risk of getting colds or flu, and there are no known side effects at this dose.  If you would like to know your vitamin D level, it can be tested with a simple blood test.  Widespread testing has shown that the vast majority of Canadians are deficient in vitamin D in the winter months.

As an added benefit, adequate levels of vitamin D is associated with decreased inflammation in the body, and decreased risks of heart disease, certain types of cancer, osteoporosis, bone fractures and Alzheimer’s disease.  Supplementing with vitamin D is an inexpensive and effective way to reduce your risk of these conditions too. 


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