Generic name of Icosin AD is Vitamin AD Drops, which is usually not recommended to be taken for a long period of time. Vitamin AD drops are divided into 2 sizes, one is taken by children from 0 to 1 year old, and the other is taken by children over 1 year old; it is usually not recommended to take it for a long period of time, mainly due to the fact that the drug instruction mentions that long-term overdosage may produce chronic toxicity; which is mainly manifested as bone and joint pain, swelling, itchy skin, fever, headache, constipation and so on. In addition, the drug instructions also clearly indicate that infants and young children are more sensitive to large quantities or yields of vitamin A, and should be used with caution; and long-term use by the elderly may lead to an overdose of vitamin A in the body and produce adverse reactions. Thus, it seems that vitamin AD drops can not be taken for a long time; it is recommended to consult a physician before taking, reasonable use of medication, to avoid overdose of drugs to cause serious adverse reactions.