The healthcare provider prescribes cyanocobalamin 100 mcg IM every 3 days for a client with pernicious anemia. The vial is labeled, "Cyanocobalamin Injection USP 1 mg/mL." How many mL(s) should the nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)

Calculation: Desired dose = 100 mcg. Available concentration and convert to matching units. Available concentration = 1 mg/mL Convert mg to mcg: 1 mg = 1000 mcg Available concentration = 1000 mcg/mL. Calculate the volume to administer in milliliters (mL). Volume to administer (mL) = Desired dose (mcg) / Available concentration (mcg/mL) = 100 mcg / 1000 mcg/mL = 0.1 mL.