The first symptom of low levels of folic acid is usually fatigue and can be followed by one or more of the following: pale skin, paranoia, rapid heart rate, anorexia, sore and inflamed tongue, weakness and weight loss. You will likely be prescribed folic acid supplements and while you wait for those to kick in, it's recommended that you rest as much as you need and avoid alcohol, tobacco, non-herbal teas, antacids and things containing phosphates, such as ice cream, beer and soft drinks, as they interfere with your body's ability to absorb iron. Furthermore, you can help your body along by eating foods high in folate, such as leafy green vegetables, liver, mushrooms, oatmeal, peanut butter, soy, red beans and wheat germ. You can find much more information about the condition, what causes it, what folic acid is good for, etc. here.