Circulating Unmetabolized Folic Acid: Relationship to Folate Status and Effect of Supplementation

Table 3

Baseline dietary and biochemical data for participants with detectable or undetectable (i.e., below the LOD) plasma concentrations of unmetabolized folic acid.

	Undetectable (𝑛=13)	Detectable (𝑛=25)	𝑃^a
Plasma folic acid (nmol/L)	—	8.8 (0.27–41.9)	—
Dietary folic acid (μg/day)	188.5 (56.8–380.0)	191.8 (70.6–395.8)	>0.99
Dietary total folate (μg DFE/day)	477.5 (181.9–849.2)	450.4 (231.9–979.4)	0.52
Plasma total folate (nmol/L)	48.7 (30.3–87.7)	43.7 (27.4–84.8)	0.27
RBC folate (nmol/L)	969.2 (761.0–1777.5)	1018.61 (710.3–2355.1)	0.88

^a𝑃 value, as determined by Wilcoxon-Mann-Whitney test (due to unequal sample sizes).