Table 1. Plasma Levels of Tryptophan Metabolites, Hypoxanthine, Pantothenic Acid, Phenylalanine, Riboflavin and Tyrosine, Reported as Median and Inter Quartile (IQR) in mg/mL, for Healthy Control (HC) and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients.

analyte		HC		ME/CFS		HC vs ME/CFS
	gender	median	IQR	median	IQR	p-value
hydroxyanthranilic acid	female	3.3	2.3–3.6	2.7	2.1–3.2	0.021
	male	3.9	3.5–4.3	3.0	2.7–3.6
hydroxykynurenine	female	5.7	4.3–7.1	5.3	4–7.2	0.003
	male	7.0	6.1–7.9	4.6	4.5–5.8
hypoxanthine	female	128.3	73.1–236.6	640.9	218.6–1075.2	0.002
	male	134.3	106.6–147.5	285.0	151.6–725.5
kynurenic acid	female	8.1	6.1–9.1	6.9	4.2–8.1	0.064
	male	9.2	8.8–10.5	8.7	8.2–9.6
kynurenine	female	280.3	272.4–327.6	345.4	262.4–384.9	0.218
	male	398.6	353.8–452.1	366.4	336.1–399.5
nicotinamide	female	36.1	29.8–43.9	24.0	17.6–29.6	0.052
	male	27.2	24.7–30.1	33.7	22.2–44.6
pantothenic acid	female	14.4	11.1–23	9.6	6.4–19.3	0.310
	male	8.8	7.9–20.4	17.5	9.1–27.5
phenylalanine	female	8145.9	7575.3–9553.5	10067.1	8067.2–11577.3	0.035
	male	8391.8	8318.3–9291.7	8728.4	8278.1–12030
quinolinic acid	female	45.0	41.8–63.5	52.1	44.8–63.9	0.087
	male	55.7	46.6–90.3	62.8	54.8–73.2
riboflavin	female	2.7	1.8–3.9	3.5	2.3–6.2	0.739
	male	3.6	1.9–4.6	3.1	1.5–8.1
serotonin	female	16.5	7–27.3	16.9	2.2–91.6	0.535
	male	17.5	11.7–24.7	2.4	1.4–87.7
tryptophan	female	12017.4	11008.3–12550.6	11564.5	10304.1–12642.2	0.394
	male	12382.7	11653.5–13148.2	12253.8	11881.1–14146.9
tyrosine	female	10408.4	9606.1–12201.6	12544.3	10778.7–13948.6	0.250
	male	13065.0	12082.3–15025.9	13070.0	11812.7–16171.4