Calcium, iron, salt, and zinc play important roles in your body. Low levels of any of these minerals can cause health problems ranging from bone disease to anemia.
Calcium
Why do I need it? Calcium helps build strong bones and teeth, keeps your nerves and muscles working correctly, and helps your blood clot. If you do not get enough calcium from food or supplements, your body will take calcium from your bones. This can make bones more likely to break. You could break ribs during chest physical therapy, while coughing, or during a fall.
How do I get it? Calcium is found in dairy products, some green vegetables, and almonds. Calcium supplements are also available. Your body can absorb only about 500 mg of calcium at a time, so spread your calcium sources throughout the day.
How much do I need? The CF Foundation recommends that you get the amount of calcium listed below. The amount of calcium listed is the total amount from your diet plus any supplement you use. The results of a bone density scan, called dual-energy X-ray absorptiometry (DXA), may show that you need more calcium. Check with your CF dietitian.
| Age | Calcium (mg) |
| 0 to 12 months | 210–260 |
| 1 to 3 years | 700 |
| 4 to 8 years | 1,000 |
| 9 years and older | 1,000–1,300 |
Iron
Why do I need it? Iron is responsible for carrying oxygen from the lungs to all the cells in the body. If you don’t have enough iron in your blood cells, you will have anemia, which can make you feel tired, cold, dizzy and irritable. It is common for people with CF to have low levels of iron (iron deficiency).1
How do I get it? Iron is found in animal protein such as beef and beef liver and in plant-based protein foods such as lima beans, kidney beans, lentils, dark green vegetables, and enriched and fortified cereals. The body absorbs the type of iron found in animal foods more easily, but both types of iron are important for overall health. Iron from plant foods and iron supplements are absorbed better if taken with a vitamin C source such as orange juice or another vitamin C-rich food.
How much do I need? There are no specific recommendations for daily iron intake for people who have CF. Most people can get enough iron from food, but sometimes an iron supplement is needed. Your CF care team can use a blood test to see if you have anemia and if you need an iron supplement.
| Food | Iron (mg) |
| Animal protein | |
| Beef liver (3 oz.) | 5.3 |
| Beef (3 oz.) | 2.6 |
| Chicken (3 oz.) | 1.1 |
| Plant-based protein | |
| Total cereal (1 cup) | 13.5 |
| Farina cereal (1 cup) | 12.0 |
| Cheerios (1 cup) | 8.4 |
| Kidney beans (1/2 cup) | 2.6 |
| Spinach (1/2 cup) | 2.4 |
Salt (Sodium Chloride)
Why do I need it? Salt (sodium chloride) plays an important role in maintaining fluid balance in the body. This means keeping the right amount of water in the right places. Salt also helps muscles contract. Not getting enough salt can slow growth and make you less hungry. It can also cause stomach pain, weakness, muscle cramps, nausea, and headache. People with CF lose a lot of salt in their sweat, so they may need more salty foods, especially during hot, humid weather.
However, if you take CFTR modulators, such as Trikafta or Alyftrek, you may not need to have as much extra salt. Talk with your CF dietitian for individual advice.
How do I get it? Table salt is the best source, along with foods that are processed with salt, such as salted nuts, olives, and cottage cheese. You can add salt to fresh foods such as meats, chicken, fish, fruits, vegetables, rice, and pasta. You can also buy canned and boxed soups and other canned foods, such as seafood, beans, and vegetables, which often have added salt. Make sure to read food labels and talk with your CF dietitian for advice.
How much do I need? No one is sure how much salt people with CF need. The usual recommendation is to eat salty foods and use the saltshaker freely at meals and snacks. People with CF who play or exercise outside in hot weather may want to add 1/8 teaspoon of salt to 1 1/2 cups (12 ounces) of a sports drink, such as Gatorade. Infants with CF should get 1/8 teaspoon of salt daily until they are 6 months old. Parents then should increase it to a 1/4 teaspoon of salt daily. It is important not to use too much salt, so ask your care team if you have any questions.
Remember, you may not need to have as much extra salt if you take CFTR modulators. Talk with your CF dietitian for advice.
Zinc
Why do I need it? Zinc has many important daily functions in the body, from growth and healing to taste and appetite. Zinc helps you fight infection, heal wounds, and develop sexually. Zinc also helps the liver release vitamin A into the blood. Low zinc levels have been linked to lower pulmonary function and bone disease in people with CF.1
How do I get it? The best food sources are oysters, beef, and beef liver. Other good sources include high-protein foods such as turkey, cheese, and milk. Many breakfast cereals are fortified with zinc. All forms of multivitamins made for people with CF have zinc, but not all over-the-counter multivitamins do. Look at the label of the multivitamin you are taking and make sure it has zinc.
How much do I need? There are no specific recommendations for daily zinc intake for people who have CF.
REFERENCES
1 Leonard, Amanda. Cystic Fibrosis Nutrition: Outcomes, Treatment Guidelines, and Risk Classification. In: Diet and Exercise in Cystic Fibrosis. San Diego, CA: Academic Press; 2015:27-34.
