If you have untreated celiac disease, or you are just starting the gluten-free diet, you may be low in a number of vitamins and other nutrients. Anyone with the “classic” presentation of celiac disease will have weight loss and obvious malnutrition. But if you are in the group of people whose celiac disease is found because of another illness, such as osteoporosis, or you have had very mild symptoms, you may not know if you need to take supplemental vitamins or minerals.
The doctor who diagnosed your celiac disease should check levels of a number of vitamins. Blood tests will demonstrate a deficiency, if present, of most vitamins, as well as some minerals and salts. The results of these tests may tell your doctor straight out that you need supplements. Other nutrients may be measured indirectly. For example, if you have osteoporosis, you will need to take extra calcium even if the levels of calcium in your blood are normal, as a part of treating the osteoporosis.
Your doctor may send you to a dietician or nutritionist to help you find nutrient-rich foods to include in your gluten-free diet. In all cases, the doctor you work with to control your celiac disease should give you guidance as to what supplements you need to take.
People with celiac disease are often anemic. In fact, many adults with CD are diagnosed because of anemia. The anemia is usually due to a deficiency of iron. Iron is lost because of the damage to the intestine caused by CD. Small amounts of blood leave the body in the stool. Over time, enough is lost to cause anemia.
Usually, if you have iron deficiency anemia, the gluten-free diet and iron-rich food will correct it. Foods rich in vitamin C help the body absorb iron.
If you are very anemic, your doctor may suggest that you take supplemental iron.
People with celiac disease can become low on B vitamins. These vitamins are not stored in the body, so that when you do not take in enough you can rapidly become deficient. On the gluten-free diet, the grains and breads are usually not enriched with these vitamins the way wheat-based cereals and grains are fortified, so that there are less B vitamins in the gluten-free diet. Additionally B12 can only be absorbed by in a specific part of the small intestine that can be damaged by CD.
Lack of vitamin B12 can cause anemia. Some people may be low on both B12 and iron. There are tests to determine the cause of anemia.
Blood tests can tell you if you are low on B12, as well as a related vitamin called folic acid. Low B12 does not only cause anemia. It can also cause other problems, including damage to the nervous system. If your CD is severe and your B12 is very low, oral B12 may not be absorbed for some time as your intestines heal. In rare cases, injectable B12 may be needed.
In at least one recent study, people with celiac disease on a gluten-free diet but low in B vitamins demonstrated an improvement in overall psychological well being when given supplements of the vitamins.
As noted above, vitamin C increases the absorption of iron, so adequate amounts of vitamin C should be taken in.
Fat soluble vitamins are stored in the body. It takes time to become deficient. However, people with untreated CD may become deficient in these vitamins including vitamin K, which is needed for blood clotting, as well as vitamins A and E.
Some people get diagnosed with celiac disease because they are found to have osteoporosis. If you have osteoporosis, it is critical to take both calcium and vitamin D supplements.
In terms of minerals, in addition to calcium and iron, some people with gluten intolerance need zinc magnesium and potassium supplements.
If you have had significant symptoms and weight loss from untreated celiac disease, your vitamin deficiencies may be obvious. Keep in mind, though, that it is possible to gain weight on a gluten-free diet and not be getting enough of the right vitamins. It is also possible to be overweight and vitamin deficient at the same time.
Many if not most people with celiac disease, even on a gluten-free diet, need supplements of some kind. There are some gluten-free products that are now enriched with vitamins, which you can look for on cereal and other labels. Your doctor should be able to give you guidance. If you want to try and get sufficient quantities of important nutrients from food, a dietician can help you with meal planning.