The answer appears to be yes and no. Getting nutrients from food is better than getting them from supplements, likely because foods are more than the sum of their parts; they give us substances we've not yet discovered and thus haven't put into the supplements. Nonetheless, even some experts take a daily multivitamin as " insurance ": If you have a bad eating day, if you are missing something from your diet, if you have a particular deficiency in something, there's likely no harm in it — except some vitamins (such as vitamins E and A) are toxic in large doses , so those must be monitored.
I've never really figured out what my requirements are and how much I'm getting from my Centrum multivitamin. I will randomly take a pill if someone suggests it without doing much research on it, without even monitoring whether it is already covered by my daily multivitamin. Twenty years ago — 20! — a doctor told me to take vitamin E and I've continued to take it. I take extra B vitamins because a co-worker once told me they increase energy. I take Biotin because a relative who also has thinning hair told me it makes hair thicker. I take vitamin D because deficiency in this one is very common, and it's hard to get from food (most professionals recommend a supplement and adequate exposure to sunlight — although contradictory information has recently emerged: Hurray!). My current doctor told me to take calcium once I hit 40.
When I added the quantities in Centrum to these extra supplements, I was shocked. In some cases I'm taking more than 2,000 percent of the recommended daily intake. Forget about the nutrition — think about the cost. For years I've been wasting money on unnecessary duplicate supplements. Years .
Also, supplements are not regulated by the FDA, meaning they are not tested and policed by an overarching agency and therefore may or may not contain what they claim in the amount they claim.