There is a lack of evidence for the benefits of multivitamins except for people with specific deficiencies, according to the President of the Australian Medical Association (AMA).
As reported by the Guardian, AMA President Michael Gannon said that while multivitamins may help people with specific nutrient deficiencies or need, in most cases this leads simply to "very expensive urine." Adjunct Associate Professor Ken Harvey from Monash University's epidemiology and preventative medicine department was equally forthright, saying that "what you need is a good diet, you're pissing the money down the toilet for no benefit." Professor Harvey outlined that there is little evidence to suggest multivitamins improve health other than in cases where clear health deficiencies existed, such as anaemia. The AMA has also been concerned that many products gain legitimacy simply by being sold in a pharmacy, despite little evidence that they work.
Whether or not you use multivitamins at present, any health concerns should be directed to a doctor for medical advice on what you should or should not take. But what is clear from the AMA's comments is that maintaining a healthy diet is one of the key means of keeping well. If you are looking for more information on healthy eating, there is information and advice from sources such as NHS Live Well and the British Heart Foundation.