It appears that people with higher vitamin D levels have a lower risk of upper respiratory infections. More research is still being done in this area but for now, there appears to be promise since vitamin D increases the production of proteins that act as natural antibiotics. I recommend clients take a vitamin D supplement, especially during winter months in Canada. We also do not receive adequate amounts of vitamin D through our diets. Speak with your dietitian if you’re uncertain about dosage of specific vitamins or mineral supplements.