The sunshine vitamin, D is produced by the skin when we're exposed to sunlight. Since many of us work inside, we may not get enough sun exposure to generate adequate vitamin D. Although recent research suggests that vitamin D may be important for a range of functions, the best evidence points to its essential role in building and maintaining strong bones.
How much to shoot for: Optimal levels of D are a subject of debate. The most authoritative source is the Institute of Medicine, which published new guidelines in 2010. It recommends that most adults get 600 international units of vitamin D a day. For people 70 and older, the recommended amount climbs to 800 international units. Most Americans can get enough in their diets, the IOM report concluded.
Where to find it: Salmon, rockfish, tuna, vitamin D-fortified milk, fortified orange juice.
Bonus nutrients: Along with vitamin D, fish are rich in omega-3 fatty acids, which protect the heart and may also slow age-related memory problems.
Simple changes you can make: Drink a glass of milk with lunch. Have a serving of a fatty fish such as salmon or sardines two or three times a week.
Most of us know that too much sodium in the form of salt can raise blood pressure. Less well known is that fact that too little potassium also contributes to blood pressure. Falling short on potassium may also increase the risk of kidney stones and osteoporosis.
How much to shoot for: Adults should get for 4,700 milligrams of potassium a day. The latest nationwide survey shows that a whopping 97% of Americans don't hit the mark.
Where to find it: Potatoes, tomatoes, spinach, carrots, beans, peas, lentils, yogurt, bananas, fish, orange juice.
Added bonus: By eating more fruit and vegetables, you'll increase your intake of vitamins A, C, and K, all of which are in short supply in the average American diet.
Simple changes you can make: Add a few bean or lentil dishes, such as split pea soup and chili, to your repertoire of home-cooked meals. Slice a banana over your breakfast cereal.
Fiber is the indigestible part of plant foods. Researchers have long known that fiber helps keep digestion regular. Newer findings show that it protects against heart disease and type 2 diabetes and may help people maintain a healthy weight.
How much to shoot for: A healthy diet should contain 14 grams of fiber for every 1,000 calories. That means most adults should get 28 to 34 grams a day.
Where to find it: Vegetables and fruit, whole grains, cooked dry beans and peas, nuts.
Bonus nutrients: Nuts are rich in unsaturated oils, which help protect against heart disease. Beans and lentils are great sources of potassium and magnesium.
Simple changes you can make: Snack on whole-grain crackers or popcorn (a whole grain). Choose breads with 100 percent whole grain flour as their first ingredient. Look for breakfast cereals with at least 5 grams of dietary fiber per serving. Add canned, rinsed chickpeas to salads, soups, or pasta dishes.