It is definitely NOT recommended to take a multivitamin. For several reasons. One of them being that you should not take everything together, like that, if you want to absorb anything. Some things should be taken with food, some not. And if it contains iron, that will wipe out everything else. Other reasons are, there's never enough of anything to deal with a true deficiency, and the ingredients are rarely the most easily absorbed, there are things you don't want, etc. ect. etc. Telling people to 'take vitamins' is about as helpful as telling them to 'get enough sleep' - what? When? How much?
What you should do, is get your vit D, vit B12, folate and ferritin tested, and just take what you need, in sufficient quantities, as indicated by the test results. Once you have those four main nutrients in hand, you can add in other things, as needed.
So, if you get those tested, and post the results on here, with the ranges, people will help you understand them, and make suggestions for supplementing.