Table 5.

Reference intervals of K, Na, and Cl in Adult Healthy Chinese Han Population in Six Age Groups

		K (mmol/l)		Na (mmol/l)		CL (mmol/l)
Age group	No.	Mean ± SD	2.5–97.5th	Mean ± SD	2.5–97.5th	Mean ± SD	2.5–97.5th
20–29s	1,181	4.2 ± 0.4	3.6–5.1	141 ± 3	136–146	104 ± 3	98–109
30–39s	938	4.3 ± 0.4	3.6–5.2	141 ± 2	137–146	104 ± 3	99–110
40–49s	934	4.3 ± 0. 4	3.6–5.2	141 ± 2	136–146	104 ± 3	99–110
50–59s	760	4.3 ± 0.4	3.6–5.1	142 ± 3	135–147	104 ± 3	99–110
60–69s	450	4.4 ± 0.4	3.7–5.4	142 ± 3	135–147	104 ± 3	99–110
70–79s	261	4.6 ± 0.5	3.7–5.6	141 ± 3	136–146	104 ± 2	99–109
Combined	4,524	4.3 ± 0.4	3.6–5.2	141 ± 3	136–146	104 ± 3	99–110