The vitamin C that is present in collards is great for strengthening immune system. With sufficient vitamin C, your body will be able to fight different kinds of disease. This leafy vegetable contains amazingly high levels of vitamin K, provides staggering 426% of recommended daily levels per 100 leaves. Vitamin K has a potential role in the increase of bone mass by promoting osteotrophic activity in the bone. It also has the beneficial effect in Alzheimers disease patients by limiting neuronal damage in their brain.