The Pros & Cons of Vitamin Supplements

Over half of Americans take some type of supplement each day, with multivitamin supplements being one of the more popular choices, according to the University of Maryland Medical Center. While there can be some benefits to taking vitamin supplements, certain supplements, or combinations of supplements, can be risky for some individuals. Getting too much of some vitamins may also cause toxicity symptoms.

Although it's best to get your vitamins from food, supplements can help make up for any shortfalls. Supplements can decrease your risk for a vitamin deficiency and any accompanying deficiency symptoms. In general, however, healthy people who follow a nutritious diet probably don't need vitamin supplements, notes a "Consumer Reports" article published in September 2010.

Many water-soluble vitamins are simply excreted by your body if you consume more than you need. Certain vitamins, however, including niacin and vitamins A, B-6, C and D, can cause toxicity symptoms when taken in high amounts. Vitamins A and D are fat-soluble, so they are stored in your body if you take more than you need. Toxicity symptoms can be relatively mild, such as itching, headache, flushed skin or an upset stomach, or they can be more severe, including kidney stones, heart rhythm issues and confusion. Although folate doesn't usually cause toxicity symptoms, it can mask the symptoms of a vitamin B-12 deficiency when taken in high amounts.

Pregnant women can benefit from taking a prenatal vitamin because they have higher vitamin needs, and the folic acid in these vitamins lowers the risk for birth defects. People who eat less than 1,200 calories per day, strict vegetarians and people who have conditions that decrease the amounts of vitamins and minerals they absorb from food may need supplements to get enough of the essential nutrients. Smoking interferes with the absorption of some vitamins, such as vitamins C and D, so a supplement may be beneficial for smokers, and older individuals also sometimes have difficulty absorbing certain vitamins from foods.

People who take certain medications may need to limit the amount of some vitamins they take due to potential interactions. For example, those taking blood thinners shouldn't take supplements of vitamins E and K and should try to keep their intake of these nutrients from foods consistent. Taking certain antioxidant vitamins, including beta carotene, can increase health risks for smokers, and pregnant women shouldn't take excessive amounts of vitamin A because this can raise their risk of birth defects.