Nutritional Deficiencies in Celiac disease (SQ-141)
Celiac disease leads to serious nutritional deficiencies that often contributes to health problems such as fatigue, anemia, osteoporosis, hair loss, mouth ulcers (canker sores), diabetes, heart disease, skin disorders and even fertility problems.
In this blog, we will explore what happens in celiac disease, how it causes loss of vitamins and minerals and what are common nutritional deficiencies related to celiac disease.
What is Celiac Disease?
Celiac disease is an autoimmune disorder in which eating food containing gluten causes damage in the small intestine. Gluten is a protein typically found in wheat, rye and barley. In some people, some kinds of gluten found in oats can also damage the gut. Gluten is also found in some medicines, lip balms and nutritional supplements such as protein powder.
Celiac disease is hereditary and does usually ‘run in the family’. People who have a first-degree relative with celiac are at a risk of developing the disease.
So, what happens if a person with celiac disease eats gluten? Indigestion of gluten triggers an inappropriate immune reaction that creates inflammation in the mucosa - the lining of the small intestine. This will damage and flatten the hair-like projections that line the inside of the mucosa, known as the villi.
Villi helps in proper digestion and absorption of nutrients. When the villi are damaged, nutrients cannot be absorbed properly into the body, leading to all sorts of nutritional deficiencies and health problems. The good news is that most of the damage to the small intestine is healed if you follow a strict gluten free diet.
Signs and Symptoms of Celiac Disease
Symptoms vary according to age, gender and duration of the disease. A person can show both digestive and non-digestive symptoms and sometimes there is no symptom at all, leading to misdiagnosis.
Typical symptoms include chronic constipation or diarrhea, bloating, gas, abdominal pain, distension, weight loss and pale, foul-smelling stools. Children, who have CD, often experience stomach pain, nausea, slowed growth and delayed puberty.
Adults often have additional symptoms – not related to digestive health – that arise because of long-term nutritional deficiencies. It happens because the inflammation and ensuing damage get more time to move to the next sections of the small intestines.
Other symptoms include unexplained anemia, low bone mineral density, bone pain, fatigue, mouth ulcers, early onset of osteoporosis, itchy skin rash (called dermatitis herpetiformis), infertility and miscarriage. It can, in severe cases, also lead to neurological and psychiatrist symptoms like epilepsy, migraines, numbness in the feet and hands, depression and anxiety. According to Celiac Disease Foundation, people with CD are twice more likely to develop coronary artery disease, and have an increased risk of developing small bowel cancers. 
People with CD are more likely to develop lactose intolerance, where your body can’t breakdown and absorb lactose. Lactose is a sugar present in milk and dairy products, and is broken down with the help of an enzyme called lactase found in the lining of the small intestine. People with recently diagnosed CD will likely have damaged structures in the small intestine leading to a loss of lactase enzyme.
People with lactose intolerance get symptoms such as diarrhea, gas, bloating and stomach cramps, after consuming milk or dairy products. These symptoms co-incidentally overlap with the symptoms of CD. Lactose intolerance in CD is generally reversed following a gluten free diet.
It is possible that you may have celiac disease but not present any tell-tale symptoms. But you may still be at risk for developing health problems linked with CD. Being asymptomatic despite having the disease is also the reason why some people may go undiagnosed for a long time, leading to high deficiencies in minerals, vitamins and macronutrients.
How does celiac disease affect nutrient absorption?
Celiac disease affects nutrient absorption in a number of ways:
1. Damage to the villi and reduced enzyme function
Celiac disease causes damage mainly to the upper part of the small intestine (proximal duodenum). The autoimmune response to gluten causes inflammation of the mucosa, the inner lining of the small intestine. This lining contains tiny finger-like projections called villi that extends into the cavity of the small intestine. The main role of the villi is to increase the surface area available for nutrient absorption.
Eating gluten makes the immune system go haywire and launch an inflammatory immune response, that damages and flattens villi. This unwanted reaction also leads to increased gut permeability, where the tight junctions along the intestinal lining develop holes. This allows some toxins, bacteria and undigested particles to slip into the bloodstream, causing food allergies, diarrhea and reduced absorption of nutrients.
Inflammation also damages microvilli, thin hair-like projections that extend from the villi. These structures help in increasing the surface area even more for enhanced digestion and absorption. Microvilli form a brush border and contain many important enzymes that are called brush border enzymes. These enzymes help in the further breakdown and absorption of nutrients into the bloodstream.
Many important vitamins and minerals, such as iron, magnesium, zinc, calcium, folate, phosphorus and fat-soluble vitamins A, D, E and K, are absorbed in the upper small intestine.
Damage to the villi in celiac leads to poor absorption of these minerals and vitamins. Many enzymes required for digestion and absorption of nutrients become depleted or lose their function in the damaged part of the small intestine. Most notably affected are the brush border enzymes present on the microvilli of the small intestines.
Undiagnosed and untreated celiac disease can cause increased villi damage and dysfunction of enzymes on the microvilli, intensifying nutritional deficiencies. Diarrhea, a major symptom in celiac, also contributes to nutritional defects.
2. Gluten-free diet
People diagnosed with celiac disease manage their problem and symptoms by following a strict gluten free diet. While it works like a charm in healing the small intestine and restoring its absorption capacity, many studies show that eating a gluten-free diet often leads to a poor nutritional profile.
Foods such as wheat, rye and barley are a good source of B vitamins and other minerals. Eliminating these foods from the diet may lead to deficiency in these nutrients. Also, a person with celiac may also develop lactose intolerance, where the body is not able to digest dairy products. This leads to restricted intake of calcium providing dairy products.
In addition, even after getting on a strict gluten free diet, mucosal recovery takes a lot of time in adults with celiac disease. During this phase, a person with celiac disease will still be vulnerable to developing deficiencies till the small intestine is properly healed and its absorption powers restored to normal.
A latest study found that people with celiac disease put emphasis mostly on avoiding gluten containing foods more than focusing on getting an overall balanced diet. On the other hand, people with irritable bowel syndrome eat healthier and have a better understanding of how diet may play a huge role in lowering inflammation. 
Nutritional deficiencies in Celiac disease
Most water-soluble vitamins (except vitamin B12) are absorbed in the upper part of the small intestines and pass directly into the bloodstream. Iron, folate, vitamin D3 are also absorbed in the duodenum.
The middle section of the small intestine (jejunum) and the upper part of ileum absorbs proteins, fats, carbohydrates, vitamin B6, and fat-soluble vitamins (A, D, E, and K). The ileum, the last section of the small intestine, is where vitamin B12 is absorbed with the help of intrinsic factor, a protein secreted by stomach cells.
Let’s look at some common nutrients that become depleted in Celiac disease. 
Iron absorption takes place mainly in duodenum, the first part of the small intestine, where the inflammation caused by eating gluten leads to much havoc.This reduces iron absorption, leading to iron deficiency anemia (IDA). Inflammatory chaos also reduces the levels of the brush border enzyme ferrireductase, needed for transporting iron across the cell membrane.
Fatigue, weakness and headaches experienced in celiac disease are often related to iron deficiency anemia. In fact, anemia is one of the most frequently occurring symptoms, and sometimes the only symptom of celiac disease and proves to be immensely helpful during the disease diagnosis.
Following a strict gluten free diet often helps in improving mild cases of iron deficiency anemia. But this correction generally takes a lot of time and usually happens months after the small intestine has healed. Taking iron supplements helps, but they should be used only after the lining of the small intestine has completely repaired.
2. B Vitamins
Deficiency of B vitamins is very common in people with celiac disease. We need B vitamins for a healthy nervous system and to convert food into energy. These water-soluble vitamins also keep your eyes, hair, nails and skin healthy.
The absorption of vitamin B9 or folate takes place mostly in duodenum and upper jejunum, the higher parts of small the intestine that are affected by CD. This leads to folate deficiency. Celiac disease is also known to cause vitamin B12 deficiency.
Both vitamin B12 and folate are required for DNA synthesis and production of red blood cells. Deficiency in these nutrients can lead to vitamin B12 deficiency or folate deficiency anemia, where the red blood cells are abnormally large. This leads to anemia related symptoms such as headache, weakness, shortness of breath and fast heart rate.
Vitamin B12 also maintains your nervous system health and its deficiency can manifest in neurological and psychiatric symptoms, such as depression, memory loss, migraine, dementia, numbness or a tingling sensation in the hands or feet. Folate deficiency is also linked with the risk of cardiovascular disease and osteoporosis. B7 or biotin deficiency caused by long-term celiac disease can cause brittle hair and nails.
Mucosal damage, diarrhea and imbalances in the gut bacteria caused by gluten can also create deficiency in vitamin B6, which plays an important role in the production of heme (a substance required to make hemoglobin), hormones and neurotransmitters. It also helps in glucose metabolism, in activation of folate, in keeping immune system functioning well and in healthy brain development. With so many functions, it is easy to see how a deficiency in B6 can impact your overall health.
It has been observed that folate and B12 deficiency can continue even when a person sticks to a gluten free diet. It is because gluten free products have very low levels of B vitamins compared to those containing gluten. In such cases, folic acid and vitamin B12 supplements can help. 
3. Calcium and vitamin D
Poor bone health and osteoporosis in patients with celiac disease is often a result of poor absorption of calcium and vitamin D.
In addition, people with this problem are at an increased risk of developing lactose intolerance by reducing intake of milk and dairy products that are a good source of calcium.
It seems that in adults with CD, adhering to a gluten free diet generally improves bone mineral density but in some patients, for example in postmenstrual women with CD, it is not enough to bring BMD within a healthy, normal range. This may increase the risk of fractures. In such cases long-term supplementation with calcium and vitamin D may help in preventing bone loss and improving bone mineral density. 
Poor absorption is the main reason why magnesium deficiency develops in celiac disease. But it may still persist despite adherence to a gluten free diet because gluten free products often contain insufficient amounts of magnesium. Taking magnesium supplements and eating a diet rich in magnesium can help correct magnesium deficiency in people on a gluten free diet.
Magnesium deficiency can cause chronic fatigue as it helps in energy production. Magnesium is involved in hundreds of biochemical reactions and is required for energy production, DNA repair, nervous system functioning and muscle health. It is also essential for the production of glutathione, one of the most important antioxidant in the body. Glutathione also removes all kinds of toxins from the body.
Poor magnesium levels can cause a variety of symptoms ranging from - migraine, painful muscle cramps and twitching, bone pain, irregular heartbeat, anxiety, irritability, poor appetite and trouble sleeping.
Long-term magnesium deficiency can also lead to osteoporosis and reduces the release of parathyroid hormone that decreases calcium levels in the blood. Magnesium plays an important role in the absorption and transport of calcium. Also, your body can’t absorb and use vitamin D without magnesium. The mineral also controls the secretion of parathyroid hormone, that draws calcium out of the bones and releases it into circulation. 
In children diagnosed with celiac disease, typical symptoms such as anorexia and failure to thrive have been linked to zinc deficiency .
Zinc is a trace mineral that is required for healthy growth and development. It is involved in DNA synthesis, wound healing and healthy immune function. It is also being recognized as an important player in maintaining the integrity of intestinal mucosa.
Zinc deficiency can cause growth retardation and it can also impact sexual maturation. It is, therefore, extremely important in addressing zinc deficiency in children with celiac disease, which is mostly resolved through gluten free diet.
Fats, carbohydrates and protein
Untreated celiac disease can lead to malabsorption of carbohydrates, fats and fat-soluble vitamins. Reduced absorption of fat can cause weight loss and poorly absorbed fat in the large intestine can cause diarrhea. Similarly, reduced absorption of carbohydrates leads to abdominal bloating and gas while malabsorption of protein can cause muscle wasting and edema.
“Celiac disease causes damage in the structures in the small intestine that help in nutrient absorption. In addition, the function of brush border enzymes (enzymes found on the microvilli) is also affected. This leads to poor absorption of many important vitamins and minerals such as iron, folate, vitamin B12, calcium, vitamin D, magnesium and zinc. If left untreated, it can cause shortage of fats, proteins, and carbohydrates.”
If you are diagnosed with celiac disease, you will have to follow a strict gluten free diet as this is the only way to heal the damage to the small intestine and restore its absorption capacity. Most nutritional deficiencies are resolved after sticking to a diet that is free of foods made of wheat, barley, rye and sometimes even oats.
It is important that you eat a healthy, well-balanced diet that replaces wheat and other glutens containing grains. Consider healthier and nutritious options like quinoa and amaranth that contain more folic acid than wheat. These cereals also provide healthy amounts of vitamin C, vitamin E and vitamin B2. 
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