Table 1.

Comparison between the no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse effect level (LOAEL), over usual consumption (UC) ratios for indispensable amino acids in rats and humans

Indispensable Amino Acid	Rat studies						Human studies
	UC	Sex	NOAEL	LOAEL	NOAEL/UC	LOAEL/UC	UC	Sex	NOAEL	LOAEL	NOAEL/UC	LOAEL/UC
	mg/kg BW/day						mg/kg BW/day
L-Histidine	290.4	M	1631	3481	5.6	12.0	31.43	F	91.2	134.1	2.9	4.3
		F	1757	3592	6.1	12.4
L-Isoleucine	519.2	M	1565	3008	3.0	5.8	50.71	NI	ND	ND	ND	ND
		F	1646	3702	3.2	7.1
L-Leucine	959.2	M	3333	ND	3.5	ND	87.14	M	500.0	ND	5.7	ND
		F	3835	ND	4.0	ND
L-Lysine	809.6	M	3357	ND	4.1	ND	75.29	M	85.7	107.1	1.1	1.4
		F	3986	ND	4.9	ND
L-Methionine	290.4	M	630	1100	2.2	3.8	25.29	F/M (9/6)	46.3	91.0	1.8	3.6
		F	ND	ND	ND	ND
L-Phenylalanine	545.6	M	1548	4903	2.8	9.0	48.57	M	169.3	ND	3.5	ND
		F	1555	4701	2.9	8.6
L-Threonine	413.6	M	3267	ND	7.9	ND	43.14	NI	ND	ND	ND	ND
		F	3673	ND	8.9	ND
L-Tryptophan	140.8	M	948	1735	6.7	12.3	13.00	F	98.4	ND	7.6	ND
		F	1956	3705	13.9	26.3
L-Valine	616.0	M	3225	ND	5.2	ND	57.00	NI	ND	ND	ND	ND
		F	1853	3721	3.0	6.0

UC is the Usual Consumption. In rats, UC is calculated, as explained in the text, according to the amount of each amino acid in standard diet designed to correspond to the requirement for rats (Reeves et al. 1993). NOAEL is the No Observed Adverse Effect Level. LOAEL is the Lowest Observed Adverse Effect Level. F and M indicate experiments performed with female and male rats, and women and men, respectively. ND means not determined. NI means not indicated. In humans, the values for UC originate from FNB/IOM 2005. The data indicated in bold allow rapid comparison of the ratios calculated in rats and humans when available