To evaluate the kinetics of intestinal absorption of vitamin E water-soluble form from the classical lipid-soluble form in a population of patients with intestinal malabsorption (hypocholesterolemias family by retention of chylomicrons).

Inclusion Criteria:

• Patient suffering from familial hypocholesterolemia by retention of chylomicrons
• Systematically followed in the department of Gastroenterology and Paediatric Nutrition in Women Mother Child's Hospital or in the endocrinology department of GHE (Louis Pradel Hospital);
• During treatment with oral vitamin E;
• over the age of 3 years and weighing over 16 kg at the time of inclusion
• For which there is a signed informed consent from the patient or parents / guardians in the case of a minor patient, and benefit from social security coverage.

Exclusion Criteria:

• Patient with encephalopathy
• Hypersensitivity to the active substance or the excipients of Vedrop
• A suspected allergy to local anaesthetics (including xylocaine)
• Patients who may not be compliant to treatment (psychiatric);
• In case of refusal to participate in the study from the patient and / or parents or legal guardian;
• Patients unable to consent (if patients with encephalopathy)