422 IS HUMAN MILK THE BEST FOOD FOR LOW BIRTH WEIGHT BABIES?

Abstract

Carcass analysis data show that the body content of N and minerals throughout fetal life are linearly related to body weight when plotted on double log coordinates. Hence they conform to the allometric (heterogonic) equation Q = bWk, where Q is total body content and b and k are constants. When differentiated this becomes dQ = bkWk-1 dW, which says that N and mineral accretions (dQ) are directly proportional to weight gain (dW) at any given body weight; and since k differs from 1.0 the accretions corresponding to a given weight gain will also vary with body weight. Nomograms (to be presented) based on these equations allow one to read off the retention of N and minerals required to support normal body composition for a given weight and weight gain (maintenance needs are extra). Application of these data to low birth weight babies indicates that human milk fed in usual amounts cannot meet the growth needs for N, Ca, P, Na and Fe in the face of rapid growth. However, it does contain enough K, Cl, Cu, Mg and S. For example, the P content of 10gm of growth tissue in a 1000 gm baby can be calculated from the above formula as follows: dP = 1.45 × 10000.164 × 10(dW) = 45 mg 200 ml human milk (i.e., 200 ml/kg) will provide only 28 mg P, while most commercial formulas will provide about 90 mg P.