What do you know about vitamins? You may be considering taking a multivitamin every day or already have a supplement routine. But is there more to consider? We’ve deconstructed these myths, uncovered some truths and offer a few tips to help you figure out what’s best for you.

Vitamin myths

Myth: It’s easy to get all the nutrients you need from food. If you ate only the most nutrient-rich foods and enjoyed a diet that covered the full spectrum of vegetables, fruits, whole grains, fats and proteins, you could get all the nutrients you need from food. However, in reality, most Americans don’t eat this way. “Foods that are affordable are nutrient-poor,” says Bruce Ames, professor of molecular and cell biology at the University of California, Berkeley, and researcher at the Children’s Hospital Oakland Research Institute. “Most people aren’t getting enough nutrients from their food. It’s hard to afford to eat what you’re supposed to eat.” Ames says a multivitamin that provides recommended daily allowances (RDAs) is an inexpensive way to ensure you get most of the nutrients you need.

Myth: Nutrients from pills aren’t as good as nutrients from food. In fact, vitamins and minerals that come from supplements can, in most cases, provide the same nutritional value as those that come from food. “An important exception is folic acid, which in most supplements comes in a slightly different from that which occurs naturally,” Ames says.

Myth: All Northerners should supplement with vitamin D. Anyone who lives north of an imaginary line drawn from Northern California to Boston experiences less sunshine, especially during winter months, than people who live farther south. Sun interacts with our skin to create vitamin D, yet not all Northerners need to supplement with D. The variables are how much time you spend in the sun, your diet and the color of your skin. “You need about 20 minutes of sunshine a day to make your vitamin D,” Ames says. “Lighter skin traps more sunshine. Dark skin protects you against too much ultraviolet light. Darker-skinned people need six times more time in the sun than lighter-skinned” in order to generate enough vitamin D. Vitamin D is also available in seafood, such as salmon, tuna and mackerel, and milk is often fortified with vitamin D. Sunscreen inhibits your skin’s ability to synthesize ultraviolet light from the sun into vitamin D.

Myth: Zinc helps your hair grow. A zinc deficiency can cause hair loss, so the first step would be to correct that deficiency, says Carol Haggans, a scientific and health communications consultant for the Office of Dietary Supplements, National Institutes of Health. “It's important to get enough zinc, but getting extra zinc doesn’t mean you will have thicker or longer hair,” she says.

Myth: B vitamins help you lose weight and prevent mosquito bites. Neither is true. While B vitamins are good for you, taking your Bs will not trigger weight loss. And keep your insect repellant; the mosquitoes will still be able to find you. “There is no research to support either claim,” Haggans says.

Vitamin truths

Truth: A woman’s menstrual cycle creates different vitamin needs. Women who are menstruating need more iron, because they lose a substantial amount of iron each month through menstruation, Haggans says. While both pre- and post-menopausal women need folic acid, getting enough folic acid is especially important for women of child-bearing age. Your nutrient needs do not vary during different times of the month, however.

Truth: Taking vitamins doesn’t affect your hunger or weight. There are no data that link vitamins with hunger or weight gain, Haggans says. The only variable would be if your vitamins and minerals came in some type of formula that contained other calories. “A vitamin pill has no calories,” she says. “Some chewable vitamins may contain a few calories, or sugar, but it’s a negligible amount.”

Truth: It is possible to consume too many nutrients. Most of the water-soluble vitamins, such as vitamin C or the B vitamins, are excreted if you take too much of them. The lipid-soluble vitamins, such as vitamins E and A, build up in your fat tissues and do not get excreted. Be especially wary of taking too many minerals, especially iron, which can build up in your body.

Truth: Vitamins can give you a stomachache. Some vitamins, when taken on an empty stomach, can cause you to feel nauseated, Haggans says. Check the directions on your vitamin package, because some nutrients are absorbed better when taken with food, while others are absorbed better when taken on an empty stomach, before eating or after eating.

Truth: Some vitamins and minerals interact negatively with medicines and with each other. If you are taking supplements and are on medication, you’ll need to check with your health care provider to find out if there are any contraindications. For example, vitamin K counteracts the effect of blood-thinning medicine. Calcium can interfere with absorption of minerals such as iron and zinc, when they are in the intestinal tract together.

Truth: Different forms of nutrient delivery don’t affect the quality of absorption. In most cases, your body absorbs synthetic and food-based vitamins similarly, Haggans says. “With a few exceptions, such as vitamin E and vitamin B12, there isn’t much documented difference between one form and another form of vitamin,” she says. Haggans says vitamin absorption can vary dramatically from nutrient to nutrient and depending on whether you are taking the vitamin on an empty stomach or with food. “All of that is taken into account in the RDA,” she says. “You don’t have to personally account for the absorption.”

Truth: It doesn’t matter what time of day you take your vitamin. Follow the directions on the vitamin package to know when it’s best to take your vitamin (on a full or empty stomach, or at separate times throughout the day), but if there aren’t specific instructions, it doesn’t matter it you take your vitamin morning, noon, or night, Haggans says.

Truth: Kids need vitamins, too. Children may need to supplement their diets, especially if they are picky eaters. “Kids can get all they need from foods and beverages, but in some cases they might not,” Haggans says. “Especially if you have a child who only eats white foods, never eats fruits and vegetables, or never drinks milk.”