Vitamins are not cure. In your case it is clear that lack of physical activity and stress are the reasons for your poor physical health. Exercise for 45 minutes 5 times a week. You need to find out time for this. Exercise may be just brisk walking, cycling, swimming, or anything which suits you, but it is must. Along with this ensure you have balanced diet. Adequate intake of proteins ( pulses, cheese, chicken, fish, mutton,lentils, soya), adequate vitamins and minerals ( green vegetables, salads, fruits, milk) will go long way in solving your problem. Ensure you drink adequate water.. minimum 2-3 litres per day or more as per your job requirement. Avoid smoking and alcohol.