Vitamin E deficiency

Vitamin E deficiency in chronic cholestasis

Chronic cholestasis represents a symptom of various conditions, where the flow or the formation of bile (a digestive fluid that helps the digestion of fats) is impaired. This results in bile salts, pigments, and fats (lipids) to accumulate in the blood stream instead of being eliminated through the digestive tract. The main organs affected are the liver and the intestine, secondary effects can involve every organ system. Albeit chronic cholestasis in itself is not a primary cause of death, it is the cause of considerable morbidity mainly due to liver disease and systemic illness.

Bile aids at the digestion of food lipids and at the elimination of certain waste products (hemoglobin, cholesterol). When bile enters the small intestine it emulsifies fats so digestive enzymes can digest them more efficiently.

Patients with chronic cholestasis cannot absorb fat soluble vitamins. Vitamin E being one of the latter, its deficiency is therefore a complication often observed in patients presenting with this condition. Vitamin E deficiency can lead to progressive demyelinisation affecting the nervous system and consequently to neurological abnormalities.

Vitamin E deficiency in cystic fibrosis

Cystic fibrosis (or “mucoviscidosis”) is the most common hereditary disorder (1 in 2500 live births in Europe). This autosomal recessive disease affects the “cystic fibrosis” transmembrane regulator factor (CTFR). The affected protein is a chloride channel. It plays a role in the creation of sweat, mucus and digestion juices. The failure of chloride conductance by epithelial cells associated to water transport abnormalities result in viscous secretions in the respiratory tract, pancreas, gastrointestinal tract, sweat glands and other exocrine tissues. Increase viscosity of these secretions makes them difficult to clear. Patients with cystic fibrosis are subjects to increased morbidity and shorter life expectancy as compared to the normal population. The most common symptoms stem from frequent lung infection and result in difficult breathing. Other symptoms include sinus infections, poor growth, diarrhea and potential infertility. There is no cure for CF, and most individuals with cystic fibrosis die young — many in their 30s and 40s from lung failure (median survival is 39 years).

The pancreas provides digestive enzymes that help to absorb fat soluble vitamins. Its thickened secretions block the movement of the digestive enzymes into the gut. The resulting malabsorption leads to malnutrition, and poor development and growth. Individuals with CF also have difficulties absorbing the fat-soluble vitamins resulting, amongst others, in vitamin E deficiency.

Unspecific neurological and hematological symptoms are induced by vitamin E deficiency. As in chronic cholestasis, vitamin E deficiency can lead to a progressive demyelinisation affecting the nervous system and consequently to neurological abnormalities.