FIELD: biotechnology, microbiology, food industry. SUBSTANCE: nonmodified microbial oil containing at least 10 wt.% arachidonic acid and eicosapentaenic acid at amount 20 wt.%, not above, of arachidonic acid content is prepared by method of microbiological synthesis using the strain of culture Pythium insidiosum. Oil is added to children nutrition at amount providing arachidonic acid content that is equal to woman breast milk. For treatment of human with deficit of arachidonic acid oil is added at pharmacologically acceptable amount. The use of invention ensures to eliminate arachidonic acid deficit in body. EFFECT: enhanced effectiveness of preparation, improved method of preparing. 27 cl, 2 tbl, 2 ex
