Research shows that one in two adults in Canada and the US are overweight. According to Statistics Canada, 18 percent of men and 16 percent of women are obese. The highest rate of obesity is among 55 to 64 year-olds: 24 percent of men and 21 percent of women in this age group are obese.

Excess weight increases risk of heart attack or stroke, diabetes and certain cancers.

Smoking has held the top spot for putting our health at risk, however, recent studies show that while smoking kills more people, the number of smokers has decreased. This decline combined with an increasing number of overweight individuals, makes obesity now the number one health risk.

Experts suggest that increasing daily vitamin D intake is the best way to raise your body's resistance to the flu this winter. Vitamin D is naturally acquired through exposure of the skin to sunlight and, to a lesser extent, from food.

Not surprisingly, studies show that 97 percent of Canadians are deficient in vitamin D during the winter months. Low levels of vitamin D will significantly impair your immune response resulting in a higher susceptibility to viruses such as H1N1, risk of complications and recovery time.

Other factors which may weaken your immune system include:

Lack of sufficient or quality sleep

Excess refined sugar in the diet

Poor stress management

Strengthening your immune system is your best defence against flu viruses. Ask your doctor to check your vitamin D levels with a simple blood test and speak to a nutritionist about supplementation options and choosing the right one for you.