I work in a software company over 10years. I have some body related tiredness and weakness building over last few years. I am not sure what is the reason. After going through some tests the doctor said it is due to d3 and b12 deficiency. I am taking the medication prescribed. But still the improvement is not much. I feel tired for no reason even after a good sleep. One of my friend who is a doctor suggested to check if it is due to chronic fatigue syndrome. Can someone suggest over this problem?