Serum vitamin E levels were measured in 19 infants weighing 1.0 to 1.5 kg, in 16 infants weighing less than 1 kg who received 65% of a vial (4.6 mg of vitamin E) of multivitamins (MVI Pediatric) daily, and in another group of 16 infants weighing less than 1 kg who received 30% of a vial (2.1 mg of vitamin E) daily. Supplementation was started within 12 hours of birth. Serum vitamin E levels were also measured after supplementation was discontinued in infants who had received 65% of a vial daily. Vitamin E sufficiency (levels equal to or greater than 0.5 mg/dL) was attained after 48 hours of supplementation in all infants receiving 65% of a vial daily and after 72 hours of supplementation in all infants receiving 30% of a vial daily. Vitamin E sufficiency was not maintained in all infants receiving 30% of a vial daily. Of the infants weighing less than 1 kg who received 65% of a vial daily, 31% had serum levels greater than 3.5 mg/dL, whereas no infant weighing less than 1 kg who received 30% of a vial daily had a level greater than 3.5 mg/dL (P less than .05). Of the infants weighing less than 1 kg who received 30% of a vial daily, 56% had levels less than 1 mg/dL v 6% of infants less than 1 kg who received 65% of a vial daily (P less than .01). Vitamin E levels decreased after MVI Pediatric supplementation with 65% of a vial was discontinued (P less than .05). After MVI Pediatric was discontinued, some infants became vitamin E insufficient.