If you’ve fallen victim to the winter time woes of catching the cold or flu this season, you’ve probably walked down the medicine aisle at the store and noticed the buy one, get one free deals on multivitamins.

They’re relatively inexpensive compared to most other supplements and may even display a flashy rainbow gradient symbolizing the wide range of micronutrients that they contain. Three studies published in the “Annals of Internal Medicine” this month, however, would suggest that you leave them on the shelf.

The first study, which involved almost 500,000 people, suggested that multivitamins provide no significant benefit for preventing cardiovascular disease or cancer. The second study, which involved 1,700 people, suggested that multivitamins provided no significant benefit for preventing a second heart attack. The third study which involved 6000 men over the age of 65, suggested that multivitamins provided no significant benefit to cognitive ability.

In the second study, people were asked to take three multivitamins per day. Those of you have taken them before know this is an excessive dose, as most on the market require only one pill per day. This likely contributed to the fact that over 50 percent of the participants stopped taking the multivitamins before the study was over, reducing the accuracy of the results. In the third study, the men involved were physicians who were already in good health, so it was unlikely that the study results would show any sizable benefit even if they actually provided one.

An important aspect of picking a multivitamin is looking at the label to determine the amount of each nutrient it contains and how that relates to your recommended daily value. If the amounts of certain nutrients are significantly more than 100 percent of your daily value, that multivitamin is probably a waste of money. Certain nutrients are safe in excess, but others can be harmful. 

The point of taking a multivitamin is to supplement possible deficiencies in micronutrients in your diet. You can determine which micronutrients you might need by recording everything you eat for a week and adding up what amount of each nutrient you get in a single day. To make things a little easier, focus on some of these nutrients that are commonly deficient in the American diet. Vitamin D is needed to regulate blood calcium levels and maintain bone health. Folic acid assists in both the building of DNA, and the breakdown of amino acids to be used by the body. Iron supports immune function and is a key part of hemoglobin which carries oxygen to tissues throughout the body.

Although we tend to focus on deficiencies, issues can arise when some of these common nutrients are consumed in excess. Niacin (B3), which assists in carbohydrate and fat digestion in proper amounts, can lower good cholesterol and increase bad cholesterol amounts in excess. Vitamin A, which is needed for color vision and bone health, can cause significant birth defects as well as a condition that yellows the skin in excess.

There are many different types of multivitamins for your gender, age, level of physical activity, and a number of other possible factors that could influence the micronutrient profile that is best for you. You can visit livestrong.com and browse some of their articles on multivitamins to get an idea of which would benefit you most or talk to your doctor the next time you are in for a check-up.

Multivitamins are meant to fill in the gaps in an already healthy diet with necessary micronutrients that may be hard to attain in proper amounts through diet alone. They are not a replacement for a healthy lifestyle which includes a well-balanced diet, regular exercise routine, modest use of alcohol and no use of tobacco products. If you were to keep a detailed food journal of everything that you ate for a week, what would it look like? Unless you are confident that you are getting a sufficient amount of the vitamins listed above, I would suggest taking a multivitamin to aid in overall good health.