B Colex syrup is used to treat anemia caused by a lack of folic acid. The treatment of arthritis. Keep the balance of microflora in your intestines in check Calcium and phosphorus are needed to build strong bones. B Colex syrup is taken with or without food, according to the doctor's instructions. The dose you receive will be determined by your medical condition and how you react to the medicine. You should continue to take this medicine for as long as your doctor advises. If you stop taking your medicine too soon, your symptoms may return and your condition may deteriorate. Tell your doctor about all other medicines you're taking, as some may interact with or be affected by this one.