By Dr. Mike Roussell
December 23, 2013

Q: The latest reports seem to say that multivitamins don't work. Should I stop taking mine?

A: Last week the findings of three studies were published in the Annals of Internal Medicine, concluding that, "supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful."

So why don't multivitamins work but eating a nutritionally complete diet will? First I don't think that you can say eating a diet that meets the recommended daily amount (RDA) for all essential micronutrients automatically makes you healthy. A healthy diet is the whole package: proteins, carbohydrates, fat, fiber, vitamins, minerals, and don't let us forget consistency. Why would we expect that a multivitamin would stop heart attacks or reduce occurrence of cancer? Nutrition and its impact on the body are more eloquent than being able to pop pills.

I use a multivitamin with clients as a means of nutritional insurance to ensure adequacy across all essential micronutrients, [Tweet this advice!] but because of the way multivitamins are formulated, much is wasted. Here are some potential reasons why a multivitamin doesn't pack the health punch you'd expect.

1. Dose: We traditionally greatly underestimate the dose of a nutrient. It is pretty clear that very high levels of vitamin A are bad for you. I'm not saying that you should stop eating carrots-I'm talking about doses only possible with supplementation. The RDA is set so that 95 percent of the population will be getting enough of a particular nutrient. If your diet is just shy of the RDA for a couple nutrients and you then add 100 percent of the RDA for those nutrients, perhaps you are still in a similar physiological dose range so it wouldn't make sense for your body to elicit a different response. It would be like if you went from driving 60 miles per hours to 65 miles per hours on the highway. Yes you are driving faster but not faster enough to get to your destination that much quicker and not fast enough to get pulled over for speeding.

2. Delivery mechanism: Most multivitamins are just a tablet or capsule packed with as many micronutrients as will fit. This is very different from vitamins and minerals in lower doses in a food matrix as they are naturally or in some fortification instances. We don't know much about the impact of the delivery mechanism of a traditional multivitamin.

3. Interference: We really have no idea about the effects of consuming more than 100 percent of the RDA for 20-plus vitamins and minerals in one shot and how these minerals interact with each other or within groups of each other. It is like with drugs: We may know the side effects of taking one drug, but when you start adding two and three other drugs, what kind of side effects come from their different interactions? This is a completely unknown area of study.

4. Broad spectrum approach: Most multivitamins are poorly designed carpet bombs that aren't formulated with your diet in mind-if they were, they wouldn't be packed full of B vitamins, beta-carotene, and vitamin C. Anyone paying some sort of attention to what they eat doesn't need another 200 percent of the RDA of vitamin C.

We should keep in mind that adding the right vitamins and minerals to your diet in the right dose can help improve health and/or reduce risk of deficiency. The fortification of folate in our food supply to prevent neural tube defects in early pregnancy has gone a long way to greatly reduce the occurrence of a horrible condition brought on by inadequate folate levels.

A low-dose multivitamin with strategic supplementation of other vitamins and minerals such as magnesium, vitamin D, and zinc on a case-by-case basis is currently your best adjunct to doing your best to eat a well-rounded diet that will give you adequate amounts of all the essential vitamins and minerals (this is no simple task!). [Tweet this tip!] But don't expect miracles from your multi. If you have the time and inclination, it may be worth having your diet analyzed to see which nutrients are lacking in your diet. Chances are that you won't need the broad nutritional spectrum of a multivitamin but instead a small handful of micronutrients that you can add to your diet in a spread-out mode.