Discover which of these vitamins you need to be taking—and which you don’t.

The use of supplements in the United States has risen in the last 20 years: While only 40% of the American adult population took supplements in 1994, the number rose to over half of all adults by 2006, according to the Centers for Disease Control and Prevention (CDC). This increase could be attributed to more people becoming concerned that they aren’t getting enough nutrients, but how do you know which vitamins you need, how much you need and how often you need them? Read on to get the lowdown on 11 of the most common dietary supplements. If you’re considering adding any of them to your healthcare regimen, be sure to talk to your doctor first about any side effects, risks or complications.

B Vitamins
There are several B vitamins, from B1 to B12, and they're all incredibly important to our body's functioning. But a commonly deficient one is B12, a nutrient that helps keep the body's nerve and blood cells healthy and helps make DNA, according to the National Institute of Health (NIH). "B12 is a common deficiency; some people just have a harder time genetically absorbing it than other people do," says Max Langhurst, a naturopathic specialist and supplements advisor at Patients Medical. "We put people on B12 because they're either low or they have a diet that doesn't support it enough. For instance, someone who has dietary restrictions, whether it be an allergen, [dairy or shellfish in particular] or a different lifestyle, like if they're not eating meat." He also says people who consume a lot of alcohol might want to supplement B12. Otherwise, Langhurst says a multivitamin should be fine. "Every multivitamin will have a spectrum of B vitamins."

Calcium
Due to the growing focus on osteoporosis and bone health, calcium supplementation rose from 28% in 1994 to 61% in 2006 among women 60 and over. "If you eat a fair amount of green leafy vegetables, dairy and meat, you're getting plenty of calcium. So to me, 500 mg a day is enough as a supplement—again 'supplement,' not 'replacement,'" says John Pan, MD, executive director at the George Washington University Medical Center for Integrative Medicine. While Langhurst recommends a bit more for anyone over 50 years old, there is a limit. "No more than 1,200 mg per day for people over 50 because there's a concern of calcium deposits [which leads to unabsorbed calcium settling into the body’s soft tissue]. Excessive calcium is also associated with mineral imbalances," he says. Dr. Pan, however, doesn't really think the problem with bone health is solely related to calcium deficiency. "Taking extra calcium doesn't hurt. We want them taking calcium, but the problem is that calcium isn't enough for bone health. Vitamin D is really more important," Dr. Pan says. "Vitamin D regulates how the body uses calcium."

Coenzyme Q10
Coenzyme Q10 (CoQ10) may not be a vitamin you've heard much about before, but it's an important one, especially for people taking certain medications for high cholesterol. "Statins (a medication millions of people around the world take) are used to lower cholesterol, but they also block the formation of CoQ10, an essential ingredient [used by] the mitochondria to make energy," says Dr. Maroon. "This can lead to muscle cramps, memory impairment and a whole lot of other complications." If you are taking a statin, Dr. Pan says your doctor should be telling you to take CoQ10. If he or she is not, ask why. "Most cholesterol drugs are a statin, which deplete CoQ10, so you really need to take an additional 10 mg," Dr. Pan adds.

Fish Oil
An important supplement for just about everyone is fish oil, which contains an omega-3 fatty acid that can help with everything from cardiovascular health and brain functioning to arthritis and inflammation. "Science is saying you need 500 mg and is encouraging people to eat cold water fatty fish (like salmon, sardines, herring, anchovies, trout and mackerel) twice a week," says Duffy MacKay, ND, a naturopathic doctor and vice president of Scientific Regulatory Affairs at the Council for Responsible Nutrition. But the reality is that people aren't eating enough fish, so fish oil supplements have become globally accepted. However, according to Langhurst, not all fish oil supplements are created equal. "You want to look for whether or not it's molecularly distilled, because that's the process that will filter out some of the metals," he says. Some of the higher-quality brands Joseph Maroon, MD, professor of neurosurgery at the University of Pittsburgh and author of The Longevity Factor, recommends include Nordic Naturals, GNC and Carlson.

Folic Acid
From 2003 to 2006, only 34% of women aged 20 to 39 used a dietary supplement containing folic acid—a number doctors would like to be higher. Folic acid is very important for women, especially during their childbearing years, because it helps prevent neural defects in fetuses and is beneficial during the early stages of development. However, sometimes women don't know they're pregnant until they are two, three or four weeks into it, which is why it’s important for young women to start taking a supplement before conception, says Dr. MacKay. Folic acid is found naturally in leafy greens, citrus fruits, beans and whole grains. "If you have a robust and varied diet with lots of fruit and vegetables, you might be one of the few Americans who can get all your nutrients from food. But for the rest of women, folic acid in a multivitamin is important," Dr. MacKay adds.

Iron
Iron is an important part of overall health, as it is an integral part of many of the body’s proteins and enzymes. Because it helps with the transportation of oxygen in the blood cells, iron deficiency can cause fatigue, poor work performance and decreased immunity. "Iron is so important and it can be hard to get with specific diets, like vegetarians, who aren’t exposed to a lot of iron. But it's one you shouldn't be supplementing unless you need to," says Dr. MacKay. "When you get a blood count at the doctor's office, that's an indicator of your iron status, so a lot of times a doctor will tell a young woman, 'You're a borderline anemic; I want you to take a multivitamin with iron in it.'" Unless your doctor recommends it, however, you do not need to take an iron supplement. "If you take too much it is not good for you," says Dr. Pan, MD.

Melatonin
Sleep disorders affect between 50 and 70 million Americans—that's nearly 20% of the population, according to the NIH. While melatonin is not a sleep aide, it can help balance a person's wake-sleep cycle. "It's a hormone produced in the pineal gland that regulates your circadian rhythm," says Langhurst. "Each person is different, but when the lights are off, your body produces it. If you are exposed to too much light, it can throw that off." Langhurst cautions that no one under 18 years old should take melatonin, because their body produces enough of it. For those over 18, Langhurst says it is safe to use for insomnia in low doses. "Start with 1 to 2 mg," Dr. Pan recommends. "That's the standard dose for sleep."

Multivitamins
According to the CDC, 40% of U.S. adults take multivitamins, making them the most commonly consumed dietary supplement. And for good reason: "If you have a good, healthy diet—you eat cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, etc.) and don't have a high meat intake—then I think you're going to get most of the nutrients you need. But the majority of people don't do that…because of the nutritional status of most people in this country I think a good multivitamin is the best place to start," says Dr. Maroon. He recommends a "targeted" multivitamin (one intended for your gender and age group), that contains B vitamins, vitamins A, C, D, E and K as well as various minerals, like calcium and magnesium. "I think the GNC products, the Mega Men and Mega Women vitamins, work well."

Vitamin C
Vitamin C, a nutrient found in foods, like citrus fruits and cruciferous vegetables, and fortified products, like juice, acts as an antioxidant, protecting cells from damage by free radicals, which are "compounds formed when our bodies convert the food we eat into energy," according to the NIH. "Vitamin C is a vitamin that's water soluble, and it's excreted very rapidly, so taking a high dose in one pill doesn't make sense," says Dr. Pan. "If you're taking 1,000 mg at a time, you're not absorbing it fast enough. So generally speaking, taking 500 mg is all you need to take. But if you want to [increase dosage] because you feel a cold coming on, then taking 500 mg three times a day is better because you're excreting it every eight hours."

Vitamin D
Vitamin D, a nutrient found in fatty fish, meat, dairy and fortified soy beverages, helps build and maintain strong bones by helping in the absorption of calcium, according to the NIH. It also helps muscle, nerve and immunity functions. While the use of dietary supplements containing vitamin D has increased for both men and women since 1988, it hasn't been enough, according to Dr. Maroon. "Vitamin D is either low or deficient in 50% to 60% of people in the United States. They should take at least 800 to 1,000 IU of vitamin D a day," he says. "And optimally, whenever an individual gets a physical examination, they should get their vitamin D level measured and then supplement accordingly." Dr. Pan agrees, saying that people really need to make sure their vitamin D levels are high enough. "Vitamin D is the only vitamin that I measure first and, depending on the level, determine how much they should be taking. Then I re-test until they get to the optimum level," he says.

Zinc
Zinc is a necessary nutrient found in the body's cells that aids the immune system, as well as helps the body grow from conception and through childhood, according to the NIH. But once you've reached adulthood, it's not necessary on a day-to-day basis says Ed Park, MD, MPH, an anti-aging expert at Recharge Biomedical Clinic. "Zinc has been shown to shorten the time of colds and flu. So if you're feeling that scratchy nose or throat, zinc will shorten that up," says Dr. Park. "But in general, zinc deficiency is not a big problem. It’s a metal, so I wouldn't recommend daily supplementation. It's not something you need to replace, like iron or calcium."


Source: 11 Common Dietary Supplements Explained