Like Alan was saying, the beta carotene form of vitamin A isn't a problem - if you look at the ingredients on the multi-v drink it will tell you what sort of vitamin A it is. The other form of Vitamin A (retinol) is the one in liver/pate etc. Its more commonly used as the vitamin a in vitamin drinks (like milo) than beta-carotene, but at least in milo, there's not enough of it to be risky for the baby (unless you eat way too much milo...!). Your drink was probably the same, you can check how much was in it against the safe limit, it will probably be lower.