Are you still trying to lose weight? or are you maintaining now?
Use the calculator on this site to work out how many calories you are using each week. Not knowing your gender or height, you probably need on average about 2000-2500 kcalories a day. Multiply this by 7 to get your weekly calorie needs, add on your weekly running expenditure then divide by 7 and you have your daily amount of calories needed to cover your running. If you still want to lose weight, then take 15% off this figure and this should help you lose about 1 pound every 7-10 days without breaking down muscle and slowing your metabolism.
If you are eating a healthy diet, you shouldn't need supplements. Most aren't in a form that the body can readily digest anyway. Make sure your fat intake is low and you are taking on complex carbohydrates (i.e. not sugary foods). Try and eat at least 74g of carbohydrate (1 gram per kilo of body weight - there are 2.2 pounds in a gram) within 2 hours of a strenuous workout to help replenish glycogen (energy) stores in your muscles.
Eat little and often, and lots of complex carbohydrates for maximum energy!
Hope that helps and good luck!