Thanks for the question.
I'm no expert in this area, but here's what I managed to find through my research:
Genetic engineering can also be used to increase the amount of particular nutrients (like vitamins) in food crops. Research into this technique, sometimes called ‘nutritional enhancement’, is now at an advanced stage. For example, GM golden rice is an example of a white rice crop that has had the vitamin A gene from a daffodil plant inserted. This changes the colour and the vitamin level for countries where vitamin A deficiency is prevalent. Researchers are especially looking at major health problems like iron deficiency. The removal of the proteins that cause allergies from nuts (such as peanuts and Brazil nuts) is also being researched.
Food products can be genetically modified to contain more cancer-fighting substances, such as anti-oxidants, which help in neutralizing harmful free radicals in the body. This helps stimulate the body’s natural defense mechanisms to better fight diseases.
http://www.writescience.com/RMT%20PDFs/Farre_2010_... (a journal article that explores nutrionally enhanced crops and food security).
For the latest on genetic engineering, go to www.genengnews.com
http://www.gm.org/ (for the latest research news)