The role of vitamin E in the nutrition of premature infants

Vitamin E (alpha-tocopherol) has been credited with a variety of beneficial effects in the premature newborn infant. It has been thought that deficiency of vitamin E is at least partly responsible for the anemia which often occurs 4 to 6 wk after premature birth, and routine dietary supplementation with vitamin E is frequently recommended. However, critical analysis reveals that published controlled studies of vitamin E supplementation do not agree on the magnitude or even the existence of this protective effect against anemia. Analysis of commonly used feeding practices suggests that the dietary ratio of alpha-tocopherol to polyunsaturated fatty acids is generally sufficient to prevent manifestations of vitamin E deficiency without supplementation. Large parenteral doses of vitamin E have been purported to protect premature infants exposed to oxygen-enriched environments and mechanical ventilation from the complications of retrolental fibroplasia and bronchopulmonary dysplasia. Subsequent studies, however, have not yet substantiated encouraging early reports of these protective effects. At present, there seems to be no clearly established need for supplementing the premature infant's usual dietary intake of vitamin E.

[Supervision of patients with artificial heart valves (author's transl)]

Valvulotomy mortality is 2--5% depending on the age and the condition of the myocardium. Ball valves, disk valves and biological prostheses are most commonly used. The most important complications of valve prostheses include bacterial endocarditis, loosening of the artificial valve, hemolytic anemias and thromboembolism. Presently, the Hancock prosthesis gives the best results. Thrombus formation, the most frequent complication of ball and disk valves--sometimes in spite of anticoagulation--does not occur with the biological prosthesis. Strict anticoagulant therapy and supervision is therefore not necessary. Should the Hancock prosthesis continue to prove satisfactory, it is to be hoped that resistance to early operation will be overcome and that the most important cause of failure, valvulotomy in an irreversible damaged heart, will thus be eliminated.

[Vitamin E deficiency and anaemia in premature infants (author's transl)]

The effect of a prophylactic treatment with tocopherol, early iron substitution and administration of polyunsaturated fatty acids in different quantities on the plasma concentration of vitamin E, hemolysis in the peroxide test and hematological parameters during the first two months of life was determined in 23 premature infants with birth weights of less than 1800 gms. In no patient in any of the different treatment groups a tocopherol deficiency (plasma concentration less than 0.50 mg/100ml) was observed and accordingly no hemolytic anemia attributable to E hypovitaminosis was found. The mean concentration of tocopherol at birth (0.51 mg/100 ml) was already above the critical limit, and no single value was found below the latter after the 10th day of life. For that reason, the amount of vitamin E included in formulas generally used in this country and its intestinal absorption have to be considered as adequate even for small premature children. The different treatments of the test groups had no significant influence on the clinical state or the hematological findings. The infants with vitamin E substitution and those without had similar hemoglobin levels. Almost all children had a distinct reticulocytosis and thrombocytosis during the second month of their life. This seems to occur naturally. The peroxide test proved to be no reliable indicator of a tocopherol deficiency in the individual case. It is not yet clear which additional factors cause vitamin E deficiency, infrequently seen in small premature infants.

Comparative effects of selenium and vitamin E in lead-poisoned rats

Weanling male rats were fed a Torula yeast diet supplemented with selenium, vitamin E, or both for 3 months. Of rats fed each diet, one group received 250 ppm lead in the drinking water and another group did not. In rats not poisoned with lead, neither vitamin E nor selenium deficiency affected spleen weight, hematocrit value, or erythrocyte mechanical fragility. Vitamin E deficiency increased the splenomegaly, anemia, and mechanical fragility of red cells of lead-poisoned rats, whereas selenium deficiency did not. Addition of 0.5 ppm selenium to the vitamin E-supplemented diet increased slightly the splenomegaly and anemia in lead-poisoned rats. Excess levels of selenium (2.5 and 5 ppm) in the vitamin E-deficient diet had little or no effect on spleen size or hematocrit of rats not receiving lead, but partially prevented the splenomegaly and anemia of red cells from either non-poisoned or lead-oisoned vitamin E-deficient rats, but not as effectively as vitamin E. These results show that vitamin E status of rats is more important that selenium status in determining response to toxic levels of lead. Excess dietary selenium did protect partially against lead poisoning in vitamin E-deficient rats, but the levels of selenium used were toxic in themselves.

Haemolysis related to mitral valve replacement with the Beall valve prosthesis

Henderson, B. J., Mitha, A. S., le Roux, B. T., and Gotsman, M. S. (1973).Thorax, 28, 488-491. Haemolysis related to mitral valve replacement with the Beall valve prothesis. Experience of valve replacement with the Beall compressed Teflon disc valve in 59 patients confirms that the incidence of clinically significant late red cell destruction is high. An apparently previously unrecorded high incidence of early haemolysis, so severe in one patient as to be directly the cause of death, is reported. In 29 patients there was massive haemolysis in early convalescence, not recognized in urine from some hours after the end of bypass and never encountered with other designs of prosthetic valve or homograft valve.