A randomised clinical trial was conducted to establish the effects of oral and intramuscular administration of vitamin K at birth on plasma concentrations ofvitamin K1, proteins induced by vitamin K absence (PIVKA-II), and clotting factors. Two groups of about 165 healthy breast fed infants who received at random 1 mg vitamin K1 orally or intramuscularly after birth were studied at 2 weeks and 1 and 3 months of age. Although vitamin K1 concentrations were statistically significantly higher in the intramuscular group, blood coagulability, activities of factors VII and X and PIVKA-II concentrations did not reveal any difference between the two groups. At 2 weeks of age vitamin K, concentrations were raised compared with reported unsupplemented concentrations and no PIVKA-II was detectable. At 3 months vitamin K1 concentrations were back at unsupplemented values and PIVKA-II was detectable in 11.5% of infants. Therefore, a repeated oral prophylaxis will be necessary to completely prevent (biochemical) vitamin K deficiency beyond the age of 1 month.

Unlike other studies, we did not identify specific biological factors, such as health and micronutrient status, which contribute to the retardation of linear growth. The normal zinc and iodine statuses of the children suggest that at least these factors are not causal.

A patient suffering froma mitochondrial myopathy leading to severe insufficiency of the voluntary muscles is described. Severe cerebral damage was present. Major biochemical symptoms were extreme lactic acidemia, hypophosphatemia and hyperphosphaturia, and generalized aminoaciduria, renal glucosuria, and polyuria. Muscular insufficiency resulted in lethal asphyxiz. All therapeutic trials were insufficient. The patient and two other children of the same family with a similar clinical picture all died before the 4th month of life. The condition is probably inherited in an autosomal recessive way. A defective respiratory chain in the mitochondria of the striated muscles is proposed as the underlying mechanism. Cytochromes aa3 were absent, b was nearly absent, but cc1 was present. In heart muscle cytochromes aa3 and b were at the level of the controls.