Essential Fatty Acids in Infant Nutrition: I. Linoleic Acid Requirement in Terms of Serum Di-, Tri- and Tetraenoic acid Levels

Abstract

Clinical observations and chemical determinations of the serum levels for the di-, tri- and tetraenoic acids in relation to the dietary intake of linoleic acid have been made on 21 infants under one year of age. The results appear to justify the conclusion that the dietary requirement for linoleic acid in healthy infants may be evaluated in terms of the blood serum levels for the di-, tri- and tetraenoic acids. As determined by alkaline conjugation of the total fatty acids and spectrographic analysis of the soaps, values < 5.0% of the total fatty acids for di- and tetraenoic acids and > 5.0% for trienoic acid are suggestive of a dietary deficiency of linoleic acid. Minimum normal levels for the di-, tri- and tetraenoic acids appear to be 10.5 ± 1.3, 2.7 ± 0.8 and 7.4 ± 2.4% of the total fatty acids, respectively. These values result when the dietary intake of linoleic acid in the form of a glyceride constitutes about 1% of the total Calories. Optimum levels for the di-, tri- and tetraenoic acids in the serum of healthy infants may well be 23.7 ± 1.8, 0.6 ± 0.2 and 10.0 ± 1.1% of the total fatty acids, respectively. These values are attained in breast fed infants in whom the linoleic acid intake is about 4% of the total Calories. Further data to be presented regarding Caloric consumption and clinical observations pertaining to the skin support the conclusions.