Table 2.

Distributions of biomarkers in women before and at early gestation (pilot study)

Biomarker	Preconception		Early pregnancy
	n	Level	n	Level
Serum folate (ng/mL), median (IQR)	620	9.7 (6.5–13.8)	577	14.5 (11.2–16.4)
Red blood cell folate (ng/mL), median (IQR)	570	247.0 (184.8–340.5)	587	417.4 (308.6–544.2)
Homocysteine (μmol/L), median (IQR)	624	6.5 (5.2–8.6)	599	4.2 (3.5–5.2)
Vitamin B12 (pg/mL), median (IQR)	625	495.2 (394.2–639.0)	600	388.5 (289.4–511.4)
Vitamin D (ng/mL), mean±SD	607	16.3±6.0	578	15.5±6.1