To keep itself running smoothly your body requires an array of essential nutrients, ranging from disease-fighting antioxidants to bone-building heavy metals. Although you can get many of these nutrients in a daily supplement, nearly all of them can also be found in the foods you eat—or should be eating—every day.
Why you need it: The vitamin A family plays a key role in immunity, reproductive behaviors, and especially vision. The A vitamins, which include beta-carotene, help the retina, cornea, and membranes of the eye to function properly.
Where to get it: The highest concentration of vitamin A is found in sweet potatoes; just one medium-sized baked sweet potato contains more than 28,000 international units (IU) of vitamin A, or 561% of your recommended daily value (DV). Beef liver, spinach, fish, milk, eggs, and carrots also are good sources.
Why you need it: Vitamin B6 is an umbrella term for six different compounds that have similar effects on the body. These compounds metabolize foods, help form hemoglobin (part of your red blood cells), stabilize blood sugar, and make antibodies that fight disease.
Where to get it: Fish, beef liver, and poultry are all good sources of B6, but the food richest in this vitamin—good news for vegetarians—is the chickpea, or garbanzo bean. One cup of canned chickpeas contains 1.1 milligrams (mg) of vitamin B6, or 55% of your DV.
Why you need it: Vitamin C is an important antioxidant, and it’s also a necessary ingredient in several key bodily processes, such as protein metabolism and the synthesis of neurotransmitters.
Where to get it: Most people think citrus when they think of vitamin C, but sweet red peppers actually contain more of the vitamin than any other food: 95 mg per serving (well ahead of oranges and just edging out orange juice, at 93 mg per serving). Other good sources include kiwi fruit, broccoli, Brussels sprouts, and cantaloupe.
Why you need it: Calcium is the most abundant mineral in the body. More than 99% is stored in—and helps fortify—teeth and bones, while the remainder goes toward blood vessel and muscle function, cell communication, and hormone secretion.
Where to get it: Dairy products contain the highest amounts of naturally occurring calcium; plain low-fat yogurt leads the pack with 415 mg (42% DV) per serving. Dark, leafy greens (such as kale and Chinese cabbage) are another natural source of calcium, which can also be found in fortified fruit juices and cereals.
Why you need it: Vitamin D, which our body generates on its own when our skin is exposed to sunlight, helps spur calcium absorption and bone growth. It’s also important for cell growth, immunity, and the reduction of inflammation.
Where to get it: Fatty fishes—including swordfish, salmon, and mackerel—are among the few naturally occurring dietary sources of vitamin D. (Cod liver oil is tops, with 1,360 IU per tablespoon, while swordfish is second with 566 IU, or 142% DV.) Most people tend to consume vitamin D via fortified foods such as milk, breakfast cereals, yogurt, and orange juice.
Why you need it: Vitamin E is a powerful antioxidant that protects cells from the harmful molecules known as free radicals. It’s important for immunity, and for healthy blood vessel function and clotting (such as occurs when you cut yourself).
Where to get it: While wheat germ oil packs more vitamin E than any other food source (20.3 mg per serving, or 100% DV), most people will find it easier to get their vitamin E from sunflower seeds (7.4 mg per ounce, 37% DV) or almonds (6.8 mg per ounce, 34% DV).
Why you need it: For pregnant women, folate—a type of B vitamin—can help prevent birth defects. For everyone else, it helps new tissues and proteins form.
Where to get it: Folate is found in a wide variety of foods, including dark leafy green vegetables, fruit, nuts, and dairy products. Beef liver has the highest concentration, but if liver’s not to your taste, spinach also has plenty: 131 mcg per half cup (boiled), or 33% of your DV. Folic acid, a man-made form of folate, is also added to many breads, cereals, and grains.
Why you need it: Proteins in our body use this metal to transport oxygen and grow cells. Most of the body’s iron is found in hemoglobin, the protein in red blood cells that carries oxygen to tissues all over the body.
Where to get it: There are two forms of dietary iron: heme iron (found in animal foods such as red meat, fish, and poultry) and nonheme iron (found in plant sources like lentils and beans). Chicken liver contains the most heme iron of any food, with 11 mg per serving, or 61% of your DV.
Why you need it: Vitamin K is a crucial ingredient in coagulation, or blood clotting. Without it, your body would not be able to stop bleeding when you bruise or cut yourself.
Where to get it: Green, leafy vegetables are the best source of this vitamin, also known as phylloquinone. Kale leads the pack with 1.1 mg per cup, followed by collard greens and spinach (about 1 mg per cup), and more exotic varieties like turnip, mustard, and beet greens.
Why you need it: This chemical pigment, found in red fruits and vegetables, appears to have antioxidant properties. Some studies suggest that lycopene may help guard against a range of ailments, including heart disease and several different types of cancer.
Where to get it: Tomatoes are the best-known source of lycopene, and sure enough, tomato products—such as sauces, pastes, and purees—contain up to 75 mg per cup. Raw, unprocessed tomatoes aren’t as lycopene-rich, however, and watermelon actually contains more per serving: about 12 mg per wedge, versus about 3 mg per tomato.
Why you need it: Lysine, also known as l-lysine, is an amino acid that helps the body absorb calcium and form collagen for bones and connective tissue. It also plays a role in the production of carnitine, a nutrient that helps regulate cholesterol levels.
Where to get it: Protein-rich animal foods, especially red meat, are good sources of lysine, as are nuts, legumes, and soybeans.
Why you need it: The body uses magnesium in more than 300 biochemical reactions. These include maintaining muscle and nerve function, keeping heart rhythm steady, and keeping bones strong.
Where to get it: Wheat bran has the highest amount of magnesium per serving (89 mg per quarter-cup, or 22% of your DV), but you have to eat unrefined grains to get the benefit; when the germ and bran are removed from wheat (as is the case with white and refined breads), the magnesium is also lost. Other good sources of the mineral include almonds, cashews, and green vegetables such as spinach.
Why you need it: Niacin, like its fellow B vitamins, is important for converting food into energy. It also helps the digestive system, skin, and nerves to function properly.
Where to get it: Dried yeast is a top source of niacin, but for something more appetizing, try peanuts or peanut butter; one cup of raw peanuts contains 17.6 mg, more than 100% of your DV. Beef and chicken liver are particularly niacin-rich, as well.
Omega-3 fatty acids
Why you need it: Fats get a bad rap, but certain types of fats—including omega-3 fatty acids, a type of polyunsaturated fat—are actually very healthy in moderation. Omega-3s contribute to brain health and may help reduce inflammation.
Where to get it: There are two categories of omega-3 fatty acids: Alpha-linolenic acid (ALA) is found in plant sources such as vegetable oil, green vegetables, nuts, and seeds, while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—the second category—are found in fatty fish. One cup of tuna salad contains about 8.5 grams of polyunsaturated fatty acids.
Why you need it: Potassium is an essential electrolyte, needed to control the electrical activity of the heart. It is also used to build proteins and muscle, and to break down carbohydrates into energy.
Where to get it: One medium-sized baked sweet potato contains nearly 700 mg of potassium. Tomato paste, beet greens, and regular potatoes are also good sources, as are red meat, chicken, and fish.
Why you need it: Riboflavin—yet another B vitamin—is an antioxidant that helps the body fight disease, create energy, and produce red blood cells.
Where to get it: At nearly 3 milligrams per 3-ounce serving, beef liver is the richest source of naturally occurring riboflavin. Not in the mood for liver? Luckily, fortified cereals (like Total or Kellogg’s All-Bran) provide nearly as much of the vitamin in a far more convenient (and palatable) package.
Why you need it: Selenium is a mineral with antioxidant properties. The body only requires small amounts of it, but it plays a large role in preventing chronic diseases. It also helps regulate thyroid function and the immune system.
Where to get it: Just six to eight Brazil nuts provide 544 mcg of selenium—that’s 777% of your DV. Too much selenium can actually be harmful, however, so stick with the mineral’s number-two food source—canned tuna (68 mg per 3 ounces, or 97% DV)—except on special occasions.
Why you need it: Thiamin, also known as vitamin B1, helps the body turn carbohydrates into energy. It’s also an important nutrient for keeping the brain and nervous system running properly.
Where to get it: As with riboflavin, dried yeast is the best food source for thiamin, containing 11 mg per 100-gram serving. However, you may find it easier to get your fill of thiamin with runners-up pine nuts (1.2 mg per serving) and soybeans (1.1 mg).
Why you need it: Zinc has been shown to play a role in immune function (you’ve probably seen it in cold remedies), and it’s also important for your senses of taste and smell.
Where to get it: Oysters contain more zinc per serving than any other food (74 mg per serving, or nearly 500% of DV), but people more often consume zinc in red meat and poultry. Three ounces of beef chuck roast, for example, contains 7 mg. Alaska King crab is a good source of the mineral, as well.