For the maintenance of optimal health, a well balanced diet consisting of a complex mixture of macronutrients (carbohydrates, fats and protein) and micronutrients (vitamins and minerals) is required. Nutrition is reported to be a major factor in infection and inflammation. Antioxidants, Vitamin A, zinc, iron and dietary fish oils appear to improve resistance to infections. Zinc, copper, selenium, n-acetylcysteine, vitamin E and dietary fish oils reduce inflammation. Calcium, vitamin C, D, and E as well as dietary fish oil reduce tissue destruction, enhance wound healing and increase the rate of bone formation and bone strength. Therefore a nutritious diet that includes adequate amounts of macro and micro nutrients could be an important component of resistance to infectious diseases such as periodontitis (gum disease).