We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
I believe that some multivitamins are almost worthless. But good vitamins from good sources are beneficial. And as far as government recommendations, you have to consider the source.
Vitamin D3 is the one to take. I've been taking it for about four years now, and more recently I've added K2 and Calcium with it. I used to get several colds a year, but I haven't been sick at all in over three years.
I do take a very good multi from time to time as well that includes zinc, and I take a very good vitamin C from time to time also. As far as Niacin -- get the non flushing kind. You don't want to experience the other one.
And Garlic? I use that a lot in my cooking. Good stuff!
I've always been one to keep a little money in all the banks. So, in my mid-80s, I still do whatever my flight surgeon/family doctor/dentist/opthamologist advises re. diet, exercise, medication, treatment and such, including a couple of vitamins and aspirin. For whatever it's worth, I'm in a good state of repair, still doing all my southern (translate: backbreaking) yard work (1/2 ac.), plumbing repairs, pool maintenance, vegetable gardening and greenhouse tending.