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. 2021 Jun 8;13(6):1976. doi: 10.3390/nu13061976

Table 3.

Self-evaluated changes in sleep quality and mental fatigue throughout the oral phenylalanine or serine supplementation period in healthy adults.

Sleep Quality Phenylalanine (n = 23) Serine (n = 30)
Baseline (7 days) 0.1801 ± 0.0769 0.3333 ± 0.1300
3 g/day (28 days) 0.2474 ± .0812 0.3058 ± 0.1442
Wash-out period (14 days) 0.1137 ± 0.1012 0.1667 ± 0.1271
6 g/day (28 days) 0.1352 ± 0.1069 0.2437 ± 0.1335
Wash-out period (14 days) 0.0648 ± 0.0718 0.1846 ± 0.1168
9 g/day (28 days) 0.0753 ± 0.0577 0.3171 ± 0.1815
Wash-out period (14 days) 0.0001 ± 0.0181 0.2949 ± 0.1840
12 g/day (28 days) 0.1316 ± 0.0615 0.3295 ± 0.1848
Mental fatigue Phenylalanine (n = 23) Serine (n = 30)
Baseline (7 days) 0.1180 ± 0.0513 0.2905 ± 0.1428
3 g/day (28 days) 0.1934 ± 0.0887 0.2908 ± 0.1310
Wash-out period (14 days) 0.1104 ± 0.1066 0.1692 ± 0.1236
6 g/day (28 days) 0.1098 ± 0.1007 0.2678 ± 0.1212
Wash-out period (14 days) 0.0715 ± 0.0657 0.1872 ± 0.1275
9 g/day (28 days) 0.0317 ± 0.0706 0.3194 ± 0.1829
Wash-out period (14 days) 0.0268 ± 0.0308 0.3026 ± 0.1800
12 g/day (28 days) 0.0946 ± 0.0457 0.3360 ± 0.1856

Values represent mean ± SEM of all tested subjects (n) over the whole period of supplementation (28 days), baseline (7 days) and wash-out recovery periods (14 days). One-way ANOVA was followed with Tukey’s multiple comparisons test between each amino acid intake, baseline and wash-out period.