Table 3.
Total amino acid levels in human milk during months 1–6 of lactation.
| TAA (µmol/L) | Month 1 (n = 23) |
Month 2 (n = 25) |
Month 3 (n = 24) |
Month 4 (n = 18) |
Month 5 (n = 23) |
Month 6 (n = 22) |
Statistical Analysis of the Changes |
|---|---|---|---|---|---|---|---|
| EAA | |||||||
| Histidine | 1872.9 ± 53.9 | 1530.9 ± 31.6 | 1462.9 ± 62.2 | 1368.1 ± 58.6 | 1278.0 ± 40.0 | 1259.7 ± 38.8 | b **, d ** |
| Isoleucine | 5112.8 ±145.9 | 4235.2 ± 98.1 | 4071.5 ± 162.7 | 3825.6 ± 167.7 | 3544.6 ± 109.6 | 3339.8 ± 79.2 | b **, d ** |
| Leucine | 9774.1 ±276.8 | 8094.0 ± 190.7 | 7748.7 ± 314.5 | 7299.3 ± 318.2 | 6813.3 ± 208.4 | 6667.9 ± 191.1 | b **, d ** |
| Lysine | 6281.0 ±169.4 | 5154.2 ± 123.1 | 4902.8 ± 202.9 | 4578.6 ± 195.9 | 4281.1 ± 128.7 | 4259.6 ± 136.7 | b **, d ** |
| Methionine | 1352.4 ±41.6 | 1068.5 ± 25.8 | 1028.2 ± 52.1 | 944.2 ± 43.2 | 879.8 ±3 1.0 | 832.6 ± 25.3 | b **, d ** |
| Phenylalanine | 3021.2±91.9 | 2452.1 ± 61.3 | 2309.4 ± 107.9 | 2154.0 ± 93.3 | 2050.6 ± 62.3 | 2089.5 ± 89.3 | b **, d ** |
| Threonine | 4800.2 ±142.3 | 3932.4 ± 94.4 | 3717.7 ± 166.6 | 3470.8 ± 144.1 | 3317.5 ± 96.5 | 3393.9 ± 146.2 | b **, d ** |
| Valine | 5727.5 ±181.5 | 4691.9 ± 103.8 | 4546.9 ± 204.6 | 4289.8 ± 187.3 | 4072.3 ± 121.2 | 4041.1 ± 141.5 | b **, d ** |
| NEAA | |||||||
| Alanine | 5573.0 ± 173.6 | 4539.4 ±108.2 | 4280.9 ± 200.3 | 4015.8 ± 169.5 | 3891.3 ± 111.7 | 4068.7 ± 205.9 | b **, d ** |
| Arginine | 2730.2 ± 104.5 | 2127.9 ± 64.6 | 2007.9 ± 117.4 | 1847.8 ± 87.7 | 1840.2 ± 64.1 | 1993.2 ± 140.6 | b **, d ** |
| Asx | 9174.8 ± 278.4 | 7383.2 ± 165.1 | 6932.7 ± 315.1 | 6475.7 ±2 74.2 | 6171.5 ± 182.2 | 6189.0 ± 244.3 | b **, d ** |
| Glx | 15,044.7 ± 397.7 | 13,123.7 ± 244.1 | 12,885.6 ± 433.4 | 12,331.7 ± 443.1 | 11,573.0 ± 294.3 | 11,274.9 ± 238.1 | b **, d ** |
| Glycine | 4115.1 ± 130.9 | 3331.5 ± 95.2 | 3105.4 ± 161.5 | 2886.6 ± 121.0 | 2808.1 ± 87.1 | 3023.6 ± 180.1 | b **, d ** |
| Serine | 5870.4 ± 180.6 | 4769.1 ± 111.4 | 4480.4 ± 202.7 | 4177.7 ± 172.4 | 3990.0 ± 118.2 | 4122.6 ± 200.5 | b **, d ** |
| Tyrosine | 2848.9 ± 89.2 | 2285.1 ± 54.1 | 2204.0 ± 98.7 | 2044.1 ± 92.7 | 1949.8 ± 59.9 | 1929.7 ± 72.7 | b **, d ** |
| SUM | |||||||
| TAA (mmol/L) | 83.3 ± 2.4 | 68.7 ± 1.5 | 65.7 ±2 .8 | 61.7 ± 2.5 | 58.5 ± 1.7 | 58.5 ± 2.0 | b **, d ** |
| Protein (g/L) | 14.4 ± 0.4 | 11.8 ± 0.2 | 11.3 ± 0.4 | 10.5 ± 0.4 | 10.0 ± 0.3 | 9.9 ± 0.3 | b **, d ** |
TAA: total amino acid; EAA: essential amino acid; NEAA: non-essential amino acid; Asx: aspartate + asparagine; Glx: glutamate + glutamine. Values are given as mean ± SEM. Significant changes (** p < 0.01) of TAA levels over time as follows: a: Significant increase from months 1–6 of lactation; b: Significant decrease from months 1–6 of lactation; c: Significant increase from month 1–3 of lactation; d: Significant decrease from months 1–3 of lactation; e: Significant increase from months 4–6 of lactation; f: Significant decrease from months 4–6 of lactation.