Baseline

(no cysteine)

Cysteine

10 mg/g AA

Cysteine

20 mg/g AA

Cysteine

40 mg/g AA

Breast fed Infants [22]

Total Intake

Calories (kcal/kg/day)

92.6 ± 13.7

99.8 ± 24.1

99.9 ± 15.8

103.9 ± 18.56

-

Protein (g/kg/day)

2.5 ± 0.22

2.5 ± 0.31

2.4 ± 0.29

2.4 ± 0.33

-

Sulfur Amino Acid Intake

Methionine (mg/kg/day)

84.5 ± 7.42

83.5 ± 10.7

80.8 ± 10.0

82.8 ± 11.3

-

Cysteine (mg/kg/day)

-

24.6 ± 3.14†

47.5 ± 5.90†

97.4 ± 13.3†

-

Taurine (mg/kg/day)

6.2 ± 0.60

6.1 ± 0.80

5.9 ± 0.80

6.1 ± 0.90

-

Total Sulfur AA (mg/kg/day)

90.8 ± 8.20

114.2 ± 15.10

125.9 ± 37.50

186.2 ± 26.30

-

Blood Concentrations

RBC GSH (μmol/L)

781 ± 122

735 ± 93.5

903 ± 118*

1203 ± 124*†

-

GSH (normalized as % baseline)

100

127 ± 25.4

153 ± 22.2*

212 ± 35.7*†

-

Tau (μmol/L)

38.2 ± 23.2

60.1 ± 8.26*

54.9 ± 5.08*

59.5 ± 6.68*

83.9 ± 9.72

Met (μmol/L)

54.4 ± 3.36

52.3 ± 2.60

53.9 ± 3.99

57.4 ± 3.78

35.8 ± 1.68

Cys (μmol/L)

35.1 ± 3.54

38.4 ± 3.91

46.3 ± 3.65*

50.3 ± 6.27*

51.9 ± 2.00

Gly (μmol/L)

270 ± 21.3

299 ± 21.1

343 ± 28.7*

323 ± 20.3*

226 ± 17.6

Ser (μmol/L)

117 ± 8.07

123 ± 6.08

137 ± 9.64*

132 ± 7.48*

159 ± 19.6

Glu (μmol/L)

52.9 ± 7.45

45.8 ± 6.72

48.9 ± 5.67

55.2 ± 6.32

134 ± 12.8

Gln (μmol/L)

390 ± 30.9

427 ± 32

461 ± 23.2

400 ± 13.8

496 ± 41.6

Total [Cys + CysH] (μmol/L)

136 ± 9.79

188 ± 13.8*

206 ± 14.0*

252 ± 17.2*†

153.4 ± 6.380

Nutritional Assessments

Weight gain (g/day)

10.3 ± 5.60

19.2 ± 11.6

29.8 ± 12.8

37.9 ± 14.4

-

Nitrogen balance (mg/kg/day)

270 ± 31.8

294 ± 31.3

270 ± 31.4

321 ± 26.8

-