How long will vitamin deficiency symptoms last if untreated?

Until treated: If you are deficient in a vitamin, the symptoms will persist (and likely even worsen over time) until the deficiency is treated by supplying adequate amounts of the needed vitamin. It may take some time for symptoms to reverse even after one takes the needed vitamin as it can take time for our bodies to recover from the damage done. It is even possible for some of the damage to be permanent.