I don't necessarily take them for cycling purposes, but here's my list:
Coq10 - 100 mg to 300 mg per day
Vitamin D - 400 IU
multivitamin
Vitamin C - 500 mg
Fish Oil
Potassium - 200 mg
Magnesium - 250 mg
Exercise specific:
GU or Bolt chews
GU gels
Recovery after long rides or hikes:
GU Recovery Drink Mix - I mix it with fat free, lactose free milk