Q: White smoke coming from A/C coolant is low?

If you are referring to "smoke" coming from the dash vents when the a/c system is running, that is simply water vapor. The refrigerant is contained in a sealed system, although not quite as well sealed as a home or office a/c system. Consequently, over a period of years, there will be some "seepage" or loss of refrigerant from most auto a/c systems. On a relatively new car such as yours, the only way there will be a meaningful loss of refrigerant is if there is a leak. If cooling efficiency seems low, that is if the air provided is not really cold, the best thing to do is request that the system be tested. If you desire a leak inspection and state of charge inspection, simply request an air conditioning system inspection and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.