Getting adequate nutrition can be a challenge as you get older. With age, the number of calories you need begins to decline. Every calorie you consume must be packed with nutrition in order to hit the mark.
Even then, you may fall short. “As we get older, the body becomes less efficient at absorbing some key nutrients,” says Katherine Tucker, RD, PhD, chair of the department of health sciences at Northeastern University in Boston. In addition, the ability to taste food declines, blunting appetite. Some foods become difficult to chew or digest.
Several key nutrients in particular may be in short supply as you get older. Here are the top vitamins and nutrients to look out for — and how to get enough of them from foods. There is a wide range of options that can accommodate a variety of dietary preferences and budgets.
B12 is important for creating red blood cells and DNA, and for maintaining healthy nerve function. “Getting enough B12 is a challenge for older people because they can’t absorb it from food as well as younger people,” says Tucker. “Even if your diet contains enough, you may be falling short.”
How to hit the mark: Eat more foods rich in B12. The richest sources include fish, meat, poultry, eggs, milk, and milk products. Talk to your doctor about whether you should take a B12 supplement.
Too little of this essential B vitamin is known for contributing to anemia and increasing the risk of a pregnant woman having a baby with a neural tube defect. Older people whose diets don’t include a lot of fruits and vegetables or fortified breakfast cereals may be falling short.
How to hit the mark: Now that breakfast cereals are fortified with folate, deficiencies are less common. “Still, if you don’t eat breakfast cereals or plenty of fruits and vegetables, it’s wise to ask your doctor if you should take a supplement that contains folate,” says Kathleen Zelman, RD.
Calcium plays many roles in the body. But it is most important for building and maintaining strong bones. Unfortunately, surveys show that as we age, we tend to get less calcium in our diets. “Calcium is so essential that if you don’t get enough, your body will leach it out of your bones,” Zelman says. Coming up short on calcium has been shown to increase the risk of brittle bones and fractures.
How to hit the mark: Help yourself to three servings a day of low-fat milk and other dairy products. Other good dietary sources of calcium include kale and broccoli, as well as juices and other drinks that are fortified with calcium. Calcium-rich foods are by far that best choice, says Robert Heaney, MD, a Creighton University professor of medicine and an expert on calcium and vitamin D. “The body needs both calcium and protein for bone health,” Heaney says. “So the ideal source of calcium is dairy products, not supplements.” If you tend to steer clear of dairy products, talk to your doctor about whether you should take a supplement.
Joanne Koenig Coste, a former caregiver who works with older people, says that smoothies made with yogurt, fruit, and even vegetables can be an attractive option for people who have lost their appetite, have trouble chewing, or have a dry mouth. “I used to make one for my mother with spinach, yogurt, a little orange juice, and a little pistachio ice cream,” she says. “My mother loved it. I’d divide it into small portions and freeze them for her. She’d take it out in the morning and have it for lunch.” Another favorite: a smoothie of vanilla yogurt, a little molasses and maple syrup, and a small scoop of vanilla ice cream.
“Vitamin D helps the body absorb calcium, maintain bone density, and prevent osteoporosis,” Zelman says. In older people, vitamin D deficiency has also been linked to increased risk of falling. Many Americans fall short on vitamin D, which is mainly produced by the skin when exposed to sunlight.
How to hit the mark: Many foods are fortified with vitamin D, including cereals, milk, some yogurts, and juices. Few foods naturally contain vitamin D. However, vitamin D is found in salmon, tuna, and eggs. Researchers are studying what the recommended level of vitamin D for optimal health should be. Many experts think older people need to take vitamin D supplements, since the skin becomes less efficient at producing the vitamin from sunlight as we age. For now, the best advice is to talk to your healthcare provider.
Getting enough potassium in your diet may also help keep bones strong. This essential mineral is vital for cell function and has also been shown to help reduce high blood pressure and the risk of kidney stones. But many older Americans don’t get the recommended 4,700 mg of potassium a day.
How to hit the mark: Fruits and vegetables are by far the richest dietary sources of potassium. Banana, prunes, plums, and potatoes with their skin are particularly rich in potassium. By helping yourself to fruits and vegetables at every meal, you can get enough potassium. If you’re considering potassium supplements, talk to your doctor first. Just as too little potassium can be a problem, too much potassium can be very dangerous for your health.
Magnesium plays a crucial role in some 300 different physiological processes. Getting enough can help keep your immune system in top shape, your heart healthy, and your bones strong. “Many whole foods, including vegetables, contain magnesium. But it is often lost in processing,” Tucker says. With age, the body isn’t as good at absorbing magnesium. Some medications older people take, including diuretics, may also reduce magnesium absorption.
How to hit the mark: Eat plenty of fresh fruits, vegetables, nuts, whole grains, beans, and seeds. They’re all are great sources of magnesium.
Fiber helps promote healthy digestion by moving foods through the digestive tract. Foods rich in fiber, including whole grains, beans, fruits, and vegetables, have many other health benefits, including protecting against heart disease. “If you don’t eat a lot of these whole foods, chances are you’re not getting enough fiber,”  Zelman says. You’re not alone. Most Americans only get about half the recommended levels.
How to hit the mark: Eat more whole grains, nuts, beans, fruits, and vegetables. Be creative. “Try adding cranberry sauce to your turkey and whole wheat bread sandwich,” Coste says. “Family can help out with this, too. When you visit your parents, divide up pumpkin seeds, nuts, blueberries, or already-chopped vegetables into snack size bags and leave them in the refrigerator so they’re ready to eat.” Talk to your doctor if you’re considering taking a fiber supplement.
These are a type of unsaturated fat. They’ve been studied for a wide range of benefits, including possibly reducing symptoms in rheumatoid arthritis and slowing the progression of age-related macular degeneration (AMD), a disease of reduced vision in the elderly. Seafood can be  be part of a heart-healthy diet but omega-3 supplements have not been shown to protect against  heart disease.
How to hit the mark: Nutrition experts recommend helping yourself to at least two servings of fish a week. Salmon, tuna, sardines, and mackerel are especially high in omega-3 fats. Some vegetable sources of omega 3 include soybeans, walnuts, flaxseed, and canola oil. Omega 3 supplements are available but  talk to your doctor before you begin taking any supplements.
If you’re an adult trying to help your parents get more omega-3s, Coste says to make it as easy as possible for them. She suggests buying canned salmon to put on salad. “You can get little cans or open bigger cans and put them in a plastic container,” she says. “Put mixed greens in another container. Then all they have to do is open the containers up and toss them together with salad dressing.”
Water isn’t a vitamin or mineral, but it is crucial for good health. With age, sense of thirst may decline. Certain medicines make dehydration more likely. Water is especially important if you are increasing the fiber in your diet, since it absorbs water.Â
How to hit the mark: One sign that you’re drinking enough is the color of your urine. It should be pale yellow. If it is bright or dark yellow, you may need to drink more liquids.
If you’re concerned that you or your aging parent isn’t drinking enough water, Coste suggests buying 4-ounce water bottles. “You see a small bottle of water and you think, ‘I can drink that,'” Coste says.
Some people may need to limit their fluids due to conditions such as kidney or liver disease. Ask your healthcare provider what’s best for you. Taking in too much fluid can be unsafe, too.