[Levels of the individual complement components in the blood serum of volunteers on diets with a various levels of optimal protein composition].

Protein fractions of complement (C3, C4, C5 and C9) and the control protein Ct-inhibitor) were studied in blood serum of practically healthy men placed on the diet marked by protein deficiency. It was noted that C3 and C9 were particularly sensitive to protein deficiency in the diet (5 to 8.2 g/day according to nitrogen), with the titers of these fractions being low.