Inside Special Report •Do You Need a Supplement? Supplement to Mayo Clinic Women’s HealthSource •Vitamin D: Are You Getting Enough? •Choosing and Using Supplements •Vitamins and Disease Prevention Vitamins and Minerals •Vitamin-Rich Foods What You Should Know About Essential Nutrients Vitamins and minerals are substances Nutrients Easy access your body needs to grow properly, Vitamin A/ One small carrot (5 inches) provides about function normally and stay healthy. It’s beta carotene 6,000 international units (IU) of vitamin A. possible — and highly recommended — Vitamin B-3 Three ounces of tuna (canned in water) that you get these substances from the (niacin) has 11 milligrams (mg) of niacin. foods you eat. However, it sometimes Vitamin B-6 One medium banana contains about 0.4 can be difficult to get the recommended mg of vitamin B-6. amount of some vitamins and minerals from diet alone. That’s why it’s not Vitamin B-9 Half a cup (4 ounces) of cooked spinach unusual to hear that taking a multivita- (folate/folic acid) contains 130 micrograms (mcg) of folate. min or other supplement on a daily Vitamin B-12 Three ounces of salmon contains about 5 basis can make good sense. mcg of vitamin B-12. Nevertheless, knowing when you Vitamin C One medium orange has about 70 mg of might need a supplement, what kind of vitamin C. vitamin and minerals are best, and how Vitamin D One cup (8 ounces) of fortified milk con- much your body needs can often be tains 100 IU of vitamin D. confusing. In this Special Report, you’ll Vitamin E One ounce of almonds (about 23 nuts) has find out why vitamins and minerals are more than 7 mg of vitamin E. considered essential to good health and what you should know about the latest Calcium One cup (8 ounces) of milk contains 300 mg of calcium. research regarding their benefits. Iron Three ounces of beef, pork, lamb or veal Food vs. supplements contains 2 to 3 mg of iron. You can get your entire daily require- Magnesium One cup of cooked spinach has 150 to 160 ments of vitamin C by just popping a mg of magnesium. pill. You can get the same amount by Potassium One medium banana has 422 mg of potas- eating a large orange. So which is better? sium. One medium baked potato (with In most cases, the orange is better. skin) contains 926 mg of potassium. Whole foods — such as fruits, vegeta- Selenium One slice of whole-wheat bread contains bles, grains and dairy products — have 10 mcg of selenium. benefits you can’t find in a pill, including: Zinc Three ounces of lean sirloin contains 5 mg • Greater nutrition. Whole foods contain of zinc. a variety of nutrients your body needs — not just one. An orange, for example, M AYO C LINIC W OMEN’ S H EALTHS OURCE 1 S PECIAL R EPORT J ULY 2009 provides vitamin C as well as beta carotene, calci- appropriate. For instance, if you don’t eat the rec- um and other nutrients. Vitamin C supplements ommended servings of fruits, vegetables and other lack these other nutrients. healthy foods, you may benefit from a multivitamin that contains a variety of essential nutrients. Multi- • Essential fiber. Fiber is important for digestion. It vitamins can also be helpful if you are a strict vege- also helps prevent certain diseases. For instance, tarian, eat a diet that’s limited because of food soluble fiber (found in beans, some grains, and allergies or intolerances, or have a disease or con- some fruits and vegetables) and insoluble fiber dition that doesn’t allow you to digest or absorb (found in whole grains and some fruits and veg- nutrients properly. Older age and certain lifestyle etables) may help prevent heart disease, diabetes habits, such as smoking and excessive alcohol con- and constipation. sumption, also can make it difficult to get all the • Phytochemicals. Many foods — including some nutrients you need from food. fruits, vegetables, whole grains, legumes and nuts As for boosting the amount of specific vitamins — contain naturally occurring food substances and minerals, there are times when this can make called phytochemicals. These substances may sense, especially for women. If you’re pregnant or help protect you against cancer, heart disease, trying to become pregnant, certain nutrients — such osteoporosis and diabetes. as calcium, folic acid and iron — are needed more than ever to protect your health and the health of Do you need a supplement? your developing baby. In addition, supplementing Although supplements may not offer all the benefits your diet with additional calcium and vitamin D is that whole foods can provide, there are times when often considered crucial following menopause to taking vitamins and minerals in pill form may be protect against osteoporosis and the risk of fractures. Having the right balance of vitamins and miner- Defining Terms als in your body is important for good health. How- ever, getting too much of some nutrients, usually When it comes to vitamins and minerals, it helps from high-dose supplements, can be dangerous. This to understand a few important terms, including: is especially true with some fat-soluble vitamins, which are absorbed and then stored in your body’s • Recommended Dietary Allowance (RDA). The fat for use as needed. Yet, it’s generally not recom- amount of each vitamin and mineral needed mended that you take megadoses of water-soluble daily to meet the needs of nearly all healthy vitamins either. Even though these vitamins aren’t people, as determined by the Food and Nutrition stored in large amounts in your body, some can be Board of the Institute of Medicine. RDAs for toxic in large amounts. Here’s more of what you vitamins and minerals are based on your sex, should know about some key vitamins and minerals. age and physical condition, such as pregnancy. Fat-soluble vitamins • Adequate Intake (AI). An AI is a recommended intake level of certain nutrients based on esti- Vitamin A/beta carotene mates of how much healthy people need. It’s Vitamin A plays a role in healthy vision, bone and used when there isn’t enough data to establish tissue growth, and reproduction. It also helps regu- an RDA. late your immune system, which prevents and fights infections. • Daily Value (DV). This term, set by the Food Research findings: Although your body can con- and Drug Administration, is used on food and vert plant sources of beta carotene into vitamin A, supplement labels. DVs are based on a 2,000- animal sources of vitamin A are better absorbed. calorie-a-day diet, but your DVs may be higher So, if you’re a vegetarian who relies on fruits and or lower, depending on your calorie needs. vegetables to meet your daily vitamin A require- • Percent Daily Value. What percentage of the DV ments, you need to eat at least five daily servings one serving of a food or supplement supplies. of these foods. Vitamin A deficiency is rare in the For instance, if the label on a multivitamin bot- United States, but people with certain diseases, tle shows that 30 percent of the DV for a vita- such as celiac disease, Crohn’s disease or pancreat- min is provided, you’ll need 70 percent from ic disorders, may have trouble absorbing the vita- other sources throughout the day to meet the min and need supplements. Dietary intake studies recommended goal. I suggest an association between diets rich in beta carotene and vitamin A and a lower risk of some M AYO C LINIC W OMEN’ S H EALTHS OURCE 2 S PECIAL R EPORT J ULY 2009 types of cancer. However, if too much vitamin A is the sunshine vitamin because your skin produces it stored in the body, it may increase the risk of birth after being exposed to ultraviolet rays from the defects, liver abnormalities and reduced bone min- sun. eral density — which could lead to osteoporosis. Research findings: Getting adequate amounts of Research has also found that beta carotene, taken vitamin D and calcium can prevent or slow osteo- in supplement form, can be dangerous. In several porosis and reduce bone fractures. A growing body recent studies, smokers and former smokers who of research also suggests that maintaining healthy took beta carotene had an increased risk of lung levels of vitamin D may reduce the risk of develop- cancer. It’s not possible, however, to get too much ing muscle pain and weakness, autoimmune dis- beta carotene from foods. eases (such as rheumatoid arthritis and multiple Recommended Dietary Allowance: 2,330 interna- sclerosis), cardiovascular disease and certain can- tional units (IU)/day (adult women), 3,000 IU/day cers. In addition, vitamin D deficiency appears to (adult men). Although beta carotene from plant be a growing problem in the United States. (See sources is considered safe, beta carotene in supple- Vitamin D: Are You Getting Enough?, below). As a ment form is not recommended as a source of vita- result, supplemental vitamin D is commonly rec- min A. ommended for many people. Adequate Intake: 200 international units (IU)/day Vitamin D (calciferol) (adults ages 19 to 50), 400 IU/day (adults 51 to 70), Vitamin D helps your body absorb calcium, a min- and 600 IU/day (adults 71 or older). Despite cur- eral that’s responsible for the normal development rent recommendations, many experts now believe and maintenance of healthy teeth and bones. This that adults should get at least 800 to 1,000 IU/day vitamin also helps maintain proper blood levels of of vitamin D.