Well, you are most water, and water is made of two parts hydrogen and one part oxygen. So, right there you know that without hydrogen you have no water, and without water, there is no life (as least no life as we know it on Earth). 

 

Hydrogen, bound mostly to carbon and nitrogen, is part of almost every molecule in your body: DNA, proteins, sugars, fats. In fact, the hydrogen bond - which forms between atoms that "share" hydrogen, is one of the most important interactions that makes biological molecules behave as they do. 

 

So, essentially everything that we see contains hydrogen, atoms bound to other atoms as part of their molecular structure... and we are no different.

Hydrogen played an important role in our body mainly as hydrogen ion (H+). As I know so far is only 2 but of course there are so much more because my lecturer keeps emphasizing how important is hydrogen ions in our body.