5 Facts About Vitamins and Your Health
Fact: Vitamins don't cancel out bad health habits.
"There are so many different disease-causing culprits in our lives that one vitamin cannot protect against them all," says Mark Moyad, MD, a FITNESS advisory board member and the director of preventive and alternative medicine at the University of Michigan Medical Center. "Vitamins can't significantly undo the toll that risk factors like smoking, excess alcohol, air pollution, obesity, and lack of physical activity take on our health," adds Jeffrey Blumberg, PhD, the director of the Antioxidants Research Laboratory at Tufts University. In fact, research suggests that some people may be more likely to put their health on the line when taking vitamins, because they believe the pills will shield them from harm.
Fact: Megadoses are useless and possibly even harmful.
"Our bodies have individual requirements for each nutrient, and once they've been met, we don't get an additional benefit from taking more, either from food or supplements," says Alice H. Lichtenstein, the director of the Cardiovascular Nutrition Laboratory at Tufts. Taking too much calcium, for example, can cause kidney stones and may increase your risk for heart attacks. What's more, some vitamins and minerals rely on the same mechanisms for absorption, "so if you flood your body with one compound, you may interfere with the absorption of other nutrients," Lichtenstein says.
Fact: What you put on your plate matters most.
Supplements are not a substitute for the nutrients found in whole foods. "Many compounds in foods may work synergistically to fend off disease," Blumberg says. Spinach, for instance, is a great source of iron, but it also contains literally thousands of other nutrients; an iron supplement contains only one. As long as you're eating a varied diet, it's extremely difficult to OD on the vitamins and minerals you get from foods, but exceeding your RDA is easy when you're popping supplements.
Fact: You're already getting enough of the key nutrients you need.
More than 90 percent of Americans have the recommended levels of several essential nutrients, such as vitamins A and D and folate, in their bodies, a new report by the Centers for Disease Control and Prevention found. "Many common foods that we eat -- for example, breakfast staples like cereal, milk, eggs, bread, and orange juice -- may be fortified with a variety of vitamins, including folic acid, calcium, vitamin D, and niacin," Lichtenstein says. Some foods are required by law to be fortified: Since 1998 the FDA has mandated the addition of folic acid to many grain products, like flour and pasta, to ensure that women of childbearing age maintain adequate blood folate levels to prevent neural tube defects. Plus many manufacturers voluntarily fortify foods (think eggs or peanut butter with added omega-3 fatty acids) to make them more appealing to health-conscious consumers. This practice, which results in what are called functional foods, is now a $41-billion-a-year industry.
Fact: Still, you're low in certain vitamins and minerals.
The CDC report found that women ages 20 to 39 have the lowest intake of iodine, a substance that is necessary for fetal brain development during pregnancy, and that African- and Mexican-Americans are most likely to fall short on vitamin D, which can help prevent conditions like osteoporosis, colds, and flu. In such instances, vitamins can help fill nutritional gaps. Supplements may also be a good idea if you no longer eat certain food groups because of certain dietary regimens, such as vegetarianism, or food allergies, Blumberg says. To find out where you may be falling short, check out the next page.
How to Pick the Best Vitamin for You
Pick the Best Vitamin
With more varieties at the drugstore than lipstick shades, it's easy to feel overwhelmed. But don't eeny-meeny-miny-mo it. Look for a logo from the nonprofit group NSF International or from the United States Pharmacopeial Convention (USP), which certifies that you're getting exactly what the label advertises.
Which vitamins, if any, do you need? Read on for expert recommendations tailored to your lifestyle.
If you are of childbearing age
Consider taking: A multi containing folic acid (400 micrograms) and iodine (150 micrograms)
Why it's crucial: About half of all pregnancies are unplanned, so having a steady level of folic acid and iodine, both essential to a developing fetus, is a must.
If you are on a calorie-restricted diet
Consider taking: A multi
Why it's crucial: If you eat less than 1,400 calories a day, you may fall short on the RDA for most vitamins and minerals.
If you are vegetarian or vegan
Consider taking: Vitamin B12 (2.4 micrograms) and zinc (8 milligrams)
Why it's crucial: Vital for red blood cell formation and cognitive function, these nutrients are naturally present mostly in animal foods. You may set yourself up for a deficiency when you nix or limit seafood, meat, and dairy.
If you are lactose intolerant or vegan
Consider taking: Calcium (500 milligrams twice a day)
Why it's crucial: Calcium is essential for bone health, yes, but many people who don't eat dairy get plenty of it from veggies like kale and broccoli as well as from fortified foods like cereal and milk substitutes. So you probably don't need the full recommended amount of 1,000 milligrams via supplement. Take only 500 milligrams or less at one time -- more than that may not be absorbed properly -- and choose calcium citrate with vitamin D, which helps your body absorb the calcium. (Vegans: D2 is plant-derived.)
If you have very heavy menstrual periods
Consider taking: Iron (18 milligrams)
Why it's crucial: Your body relies on iron to manufacture hemoglobin, a blood protein that shuttles oxygen from your lungs, but your level may get depleted during heavy periods. Up to 20 percent of U.S. women experience iron-deficiency anemia (symptoms include fatigue, shortness of breath, and difficulty concentrating).
If you live north of Atlanta and/or regularly wear sunscreen
Consider taking: Vitamin D (1,000 international units; the RDA is 600 international units)
Why it's crucial: Due to the angle of the sun in northern latitudes during the winter, your skin is unable to manufacture vitamin D from its rays for four to six months of the year. Wearing sunscreen, while important for preventing skin cancer, also blocks the vitamin's production.
If you eat fish less than twice a week
Consider taking: Omega-3 fatty acids (about 1,000 milligrams total of DHA and EPA, the types found in fish oil)
Why it's crucial: Omega-3 is an essential fatty acid, which means your body can't make it, so you need to get it from your diet. It's necessary for brain health, and recent studies suggest that it may also help relieve depression, anxiety, and muscle pain.
Sources: Jeffrey Blumberg, PhD, the director of the Antioxidants Research Laboratory at Tufts University, and Mark Moyad, MD, the director of preventive and alternative medicine at the University of Michigan Medical Center
Originally published in FITNESS magazine, September 2012.