I am always feeling tired and i have no energy. i am only 27 years old so i shouldn't be feeling this way. am i lacking vitamins?

Possible: There are too many causes for fatigue to list here. Generally, if you eat a normal diet, there shouldn't be vitamin deficiency significant enough to cause your symptoms. You should see your doctor for a general evaluation and work up the abnormalities. Thyroid problems, sleep apnea are two common reason for fatigue that should be ruled out.