Feeling like a zombie even after eight solid hours of counting sheep? You're not alone -- women complain of fatigue and tiredness twice as much as men. Sleepy symptoms can be exacerbated by the tasks many women find themselves taking on, including a career, household chores, caring for children...oh, and having a social life.

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However tiring these things can be, there could be more to blame for tiredness than just a busy schedule. From minor irritants to life-threatening - check out the things that could be zapping your energy.

1. Vitamin B12 Deficiency - The vitamin B12 helps maintain energy by boosting your oxygen level in red blood cells. If you don't get enough, you could feel fuzzy, sleepy and even constipated. If left untreated, a vitamin B12 deficiency can lead to memory and confusion problems as well. A simple B12 blood test from your primary care physician can tell you if you're low. A supplement and including more meat and dairy in your diet can help normalize your levels and have you feeling more energized.