I've been taking a good amount of supplements daily for years now, and I think they're very beneficial. I feel good and rarely get a cold, etc. I don't take cheap vitamins, they are useless, I try to get ones from the vitamin store which show potency, etc.
I don't take pills like centrum, I understand that they don't even dissolve in the body sometimes, and are just passed out with waste. I always take capsules, herbs usually liquid tincture.
I take vitamin D3, k2 and magnesium...things like that for my bones, no calcium. Calcium carbonate is the worst form that people take, as it isn't well absorbed in the body, and much of the calcium ends up in the arteries, not helping the bones, but causing things like strokes. My father in law had a major paralyzing stroke, and they said his carotid artery was 99% calcified, he took oyster shell calcium daily. The k2 helps any calcium from foods, etc. to stay out of the arteries. I don't take any calcium or iron now, too much iron is not good for post menopausal women, and the only way to get rid of it is to give blood. Even my multi is iron-free.
I don't always eat as healthy as I should, and I don't get enough vitamins and minerals from vegetables and fruits, never have. So supplements for me make sense, so far no complaints. I'm not on any prescription meds like others in my family, so in my 60s, I think that's a very good thing. The side effects are worse than the condition, I'd rather take things more natural, even if I have to pay out of pocket, it's worth it to me.