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.