Table 4.

Reference intervals of vitamin levels in general population and pregnant women.

	Vitamin D (ng/mL)	Vitamin A (mg/L)	Vitamin E (mg/L)
Reference values in general population	>15a; >25b	>0.22c	5–18d
Reference values during pregnancy
Total population	5–43	0.22–0.62	7.4–23.5
Gestational age
1st trimester	5.3–35.6	0.26–0.63	7–19.4
2nd trimester	5.3–45	0.24–0.65	8.5–22.5
3rd trimester	3.2–46.8	0.19–0.62	9.4–26.4
Season
Spring	4.6–33.6	0.23–0.67	7.6–23.9
Summer	7.5–50.4	0.22–0.6	7.2–22.8
Autumn	5.8–41	0.21–0.58	7.4–23.2
Winter	4–31.1	0.22–0.63	7.7–24.2

^aGraham (26).

^bHolick et al. (27).

^cBastos Maia et al. (23).

^dKratz et al. (30).