To help strengthen the immune system I would say the best vitamin to take is vitamin C and the best mineral to take would be zinc. Considering the colitis, make sure the vitamin C is in a buffered form. When the vitamin C is buffered (in the form of calcium ascorbate) it won't irritate the digestive tract in high doses (bottles will either say 'buffered' or 'ester'). Zinc is also great for supporting immune function but should be taken with food to both help it's absorption and to avoid any stomach upset. I find with my patients working through inflammatory bowel disease, probiotics are essential and I find the best results with brands that include a 'prebiotic' in them such as FOS/fructooligosaccharide. Omega-3 fatty acids/fish oils can be quite beneficial as well as they also support the immune system, support the health of tissue that has a rapid cell turnover (such as the mucous membranes of the digestive tract) and acts as an anti-inflammatory. Ideally, you should also start working with a Naturopathic Doctor or nutritionist to get an idea of what types of foods will be best suited to your individualized needs, as diet has a huge impact on how well colitis can be controlled.
Response by Jeff Appelmann BSc, ND