As we get older we eat less, so can easily end up not eating enough to get the balance of minerals, vitamins and other trace elements we need - even if are smaller diet is high in fruit and vegetables, nor is it always possible to have plenty of exposure to the sun, especially in winter and if you live in an urban area.
Obviously if you start taking huge doses of one particular supplement there will be dangers, but I can see no harm, and probably benefits in taking a daily multimineral and vitamin tablet.
The cost of a mineral and vitamin tablet, is very little compared with the money many people spend on alcohol or other minor life enhancers.
I reckon that over a year I probably spend no more on suplements as I do on having my eyebrows tinted and tidied every 6 weeks.