The occurrence and effects of human vitamin E deficiency. A study in patients with cystic fibrosis.

The role of vitamin E in human nutrition was studied by investigation 
of patients with cystic fibrosis (CF) and associated pancreatic insufficiency. Vitamin 
E status was assessed by measurement of the plasma concentration of 
the principal circulating isomer, alpha-tocopherol. Results of such determinations in 52 
CF patients with pancreatogenic steatorrhea revealed that all were deficient in 
the vitamin. The extent of decreased plasma tocopherol varied markedly but 
correlated with indices of intestinal malabsorption, such as the serum carotene 
concentration and percentage of dietary fat absorbed. Supplementation with 5-10 times 
the recommended daily allowance of vitamin E in a water-miscible form 
increased the plasma alpha-tocopherol concentrations to normal in all 19 CF 
patients so evaluated. Studies on the effects of vitamin E deficiency 
focused on possible hematologic alterations. An improved technique was developed to 
measure erythrocyte hemolysis in vitro in the presence of hydrogen peroxide. 
While erythrocyte suspensions from control subjects demonstrated resistance to hemolysis during 
a 3-h incubation, all samples from tocopherol-deficient CF patients showed abnormal 
oxidant susceptibility, evidenced by greater than 5% hemoglobin release. The degree 
of peroxide-induced hemolysis was related to the plasma alpha-tocopherol concentrationin an 
inverse, sigmoidal manner. The possibility of in vivo hemolysis was assessed 
by measuring the survival of 51Cr-labeled erythrocytes in 19 vitamin-E deficient 
patients. A moderate but statistically significant decrease in the mean 51Cr 
erythrocyte half-life value was found in this group. Measurement of erythrocyte 
survival before and after supplementation of 6 patients with vitamin E 
demonstrated that the shortened erythrocyte lifespan could be corrected to normal 
with this treatment. Other hematologic indices in deficient subjects, however, were 
normal and did not change upon supplementation with vitamin E. It 
is concluded that CF is invariably associated with vitamin E deficiency, 
provided that the patient in question has pancreatic achylia and is 
not taking supplementary doses of tocopherol. Concomitant hematologic effects consistent with 
mild hemolysis, but not anemia, occur and may be reversed with 
vitamin E therapy. Patients with CF should be given daily doses 
of a water-miscible form of vitamin E to correct the deficiency. 
