11/06/2014 08:53 pm ET Updated Jan 06, 2015

The 5 Most Common Mistakes People Make When Choosing a Multiple Vitamin

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If you are one of the 40 percent of Americans taking multiple vitamin/mineral supplements or are thinking you really should take a dietary supplement, be sure to avoid making one of these five common mistakes when buying.

1. Assume they are all pretty much the same.
"When I asked my doctor which multiple to take, he said to just pick one," a client reported uncertainly. "That doesn't seem right."

She is right to follow her instincts. Multiple vitamin and mineral supplements are targeted to different populations and needs. From low potency one-a-days for those who want minimum support but do not want to swallow many pills to a complete overhaul nine-a-day program for the fully committed health enthusiast. There are gentle food-based supplements and high-potency supplements for those with greater needs. Supplements geared to women of childbearing age can be full of iron, a mineral most men and older women should generally avoid. Before throwing a random bottle into your cart, gather more info to see which one will suit you best.

2. Neglect to look at the other ingredients.
Some of the bestselling multiples are full of additives health conscious consumers go to pains to avoid in their food. Look at the full list of ingredients and avoid supplements with artificial colors and too many hard to pronoun ingredients beyond the nutrients themselves.

3. Assume Daily Value (DV) is the ideal goal for nutrients.
One of the most common misconceptions about nutrition is that the DV for nutrients listed on the side of food containers and supplement bottles is a government sanctioned optimal nutrient goal. Some people even believe you should not exceed the DV. In fact, the DV is a bare minimum standard set to assure that most people will not develop a nutrient deficiency symptom. Between symptoms of malnutrition and robust health is a lot of gray area.

The idea of supplements is to close nutrition gaps common in most people's diets. Even if you are a pristine eater, bad digestion, medications, illness, food sensitivities, environmental toxins or even individual quirks can increase your need for nutrients beyond a bottom line standard.

4. Are seduced by non-significant extras.
We all want as much as we can get for our money so a supplement with a long list of ingredients is appealing. Expensive specialty nutrients like co-enzyme Q10 or food concentrates can make a supplement look comprehensive but can be present in such miniscule amounts that they are not an important consideration. One otherwise nice formula listed 10mg of a vegetable concentrate. That is literally a speck of vegetables. Better to eat your Brussels sprouts.

5. Expect too much from a multiple.
It is always best to eat the highest quality, nutrient rich diet you can. No multiple vitamin/mineral can make up for a fast food, sugar laden, highly processed diet. Nor can a single multiple vitamin and mineral prevent cancer or dementia as recent studies have shown. But there is no single medication that can accomplish these feats either because they are unrealistic.

Just because a single multiple will not prevent dementia does not mean it is worthless. A more realistic expectation is that a multiple will close small, common gaps found in most people's diets or boost borderline nutrient intakes to a healthier level. The biggest gap in most people's diets is the difference between what they think they eat and what is actually consumed.