Nutritional and Infections
The interaction between nutrition and  infection  is  synergistic -  that is  nutritional deficiency lowers resistance  to infection and infection aggravates  existing malnutrition. Individuals who are chronically undernourished not only succumb to infection more readily but  take a  longer  period  to  recover than do the well nourished. There are series of  studies to show  the specific  roles of  nutrients  like vitamin A, vitamin C, vitamin E,  omega 3  fatty acids, trace minerals like iron, zinc which have a role either in terms of maturation, number and/ or activity of T cells and B cells. These have an influence on the cellular and humoral immunity. If  you wish  to go  into the details of specific role of  individual nutrients in the immune process, you could refer  to some additional references listed, at  the end of  this course.