Vitamins and Workouts

I have been getting exhausted quite easily lately. It's probably because of being remiss in taking my vitamins and iron pills. And also because I haven't been getting enough exercise thus my stamina is really way low. I used to withstand staying up so late several nights in a row and still accomplish a lot with my online work. But now I just couldn't get as much done as before because I get tired easily like I'm taking some natural sleep aid that makes me hit the sack early. I have to put things in the right perspective starting with regularly taking my vitamins. I started going to the gym again after my workout schedule got interrupted with other priorities.