Plasma and Red Cell Reference Intervals of 5-Methyltetrahydrofolate of Healthy Adults in Whom Biochemical Functional Deficiencies of Folate and Vitamin B₁₂ Had Been Excluded

Table 1

Summary of results of 𝑁=126 subjects used to derive 5-MTHF reference intervals.

	Females 𝑁=69 mean (SD); median	Males 𝑁=57 mean (SD); median	Student’s 𝑡-test 𝑃 value	All 𝑁=126 mean (SD); median
Age (range)	38 (10); 38 (23–60)	38 (12); 36 (19–64)	0.730	38 (11); 37
tHcy (μmol/L)	8.4 (1.8); 7.9	9.7 (2.1); 9.7	<0.001	8.9 (2.1); 8.9
MMA (nmol/L)	116 (93); 101	112 (76); 100	0.794	114 (85); 100
Plasma 5-MTHF (nmol/L)	19.4 (8.5); 19.1	18.7 (8.2); 17.8	0.624	19.1 (8.3); 18.2
Redcell 5-MTHF (nmol/L)*	583 (222); 572	585 (164); 557	0.975	586 (197); 560
Whole blood 5-MTHF (nmol/L)	618 (229); 592	611 (172); 582	0.838	615 (205); 584

∗Result adjusted for plasma 5-MTHF content.