Malabsorption Of Nutrients

Malabsorption of nutrients is a condition that is usually related to diseases of digestive tract. Nutrient absorption takes place mainly in mucosa of small intestine. Proper absorption needs presence of pancreatic digestive enzymes and bile. Disorder in any of these factors results in malnutrition.

Celiac disease

This is a very common autoimmune disorder that is caused by an aggressive immune response against small intestinal mucosa after contact with digested gluten. Gluten is a protein substance present in cereals. Untreated celiac disease results in chronic inflammation of intestinal mucosa and malabsorption of a certain degree.

Milk intolerance

This condition is more precisely referred to as lactose intolerance. Lactose is a sugar present in milk that is digestive thanks to enzyme known as lactase located in small intestinal mucosa. Many adults suffer from lactase deficiency resulting in milk malabsorption and diarrhea.

Crohn’s disease

Crohn’s disease is an autoimmune disorder that can attack virtually any part of digestive tract. It quite usually attacks the small intestine and possible malabsorption depends on the location and extent of the inflammation.

Gastrointestinal infections

Acute infections are not related to a malabsorption syndrome of nutrients but they can cause dehydration because of an acute diarrhea. However, chronic infections may be related to malnutrition, for example the Whipple’s disease and intestinal parasitic infections (tapeworms).

Pancreatic disorders

Any pancreatic disease that results in lack of its digestive enzymes can cause malabsorption as intestinal mucosa is unable to absorb nutrients undigested by pancreatic enzymes. Classic diseases causing this condition are for example chronic pancreatitis, cystic fibrosis and extensive pancreatic cancers.

Biliary disorders

Bile is important especially for fat digestion as it helps to disperse fat particles and makes them more sensitive to pancreatic digestive enzymes. Bile flow may be disrupted especially in obstruction of the bile duct by a gallstone or by a nearby growing tumor (usually gallbladder cancer or pancreatic cancer) and more rarely by some autoimmune disorder such as primary biliary cirrhosis and primary sclerosing cholangitis.

Short bowel syndrome

Short bowel syndrome means the loss of certain extent of small intestinal absorption surface. Usually this follows surgical interventions related to removal of an intestinal section. Let just add that complete removal of small intestine would be fatal. The intestine may be also shortened by formation of unnatural bypasses such as intestinal fistulas accompanying abscesses in infectious diseases and Crohn’s disease.

Blind loop syndrome

This means a condition when small intestine is colonized by a larger number of bacteria. Bacteria are common in large intestine but in small intestine they can alter proper bile function and disrupt absorption of vitamin B12.


Amyloidosis is a systemic disease caused by the accumulation of a protein substance known as amyloid in body tissues and organs. Intestinal amyloidosis affects the ability to absorb and digest nutrients causing malabsorption and diarrhea.

General causes

Not only digestive tracts disorders can cause malabsorption. This problem can occur also in untreated overactive thyroid gland and chronic diabetes.


The symptoms depend on the causative factor and on lack of certain substances. Generally there is present weight loss, insufficient growth in children and menstruation problems in fertile women. The lack of protein is related to tissue edema, muscle atrophy, brittle nails, brittle hair and increased hair loss. Undigested nutrients stay in stool and cause diarrhea. Undigested fats cause yellowish and oily appearance of stool. Malabsorption of iron has severe consequences including iron-deficiency anemia. Lack of vitamins is another problem, for example deficiency of vitamin B12 causes pernicious anemia, lack of vitamin D causes osteoporosis and vitamin K deficiency may cause bleeding complications (for example easy bruising).

Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources