The Essential Fatty Acid Requirement of Infants and the Assessment of Their Dietary Intake of Linoleate by Serum Fatty Acid Analysis

The content of polyunsaturated fatty acids in serum total fatty acids was related to the dietary intake of linoleate in 243 infants two to four months of age and in 197 infants eleven to twelve months of age. The curves relating triene:tetraene ratio to dietary linoleate indicated approximately 1 per cent of total calories as minimal linoleate requirement. The exponential equations relating dienoic, trienoic and tetraenoic acids to dietary linoleate were derived by computer methods. These yielded constants from which the minimal nutrient requirement could be calculated. The best estimates were obtained from the triene and tetraene data for two to four month old infants and were found to be approximately 1.4 per cent of the caloric intake. The nutritive status with respect to linoleate may be estimated by means of logarithmic regression equations. The equation for two to four month old infants is: log10 dietary linoleate = –1.087 + 0.0432 (di - tri + tetra) The data for eleven to twelve month old infants were found to have greater scatter and give lower triene:tetraene ratios at comparable linoleate intakes. The scatter and displacement are considered to be due to supplements of solid food to the basic diet not considered in the calculated dietary linoleate.