Table 1.

Acute lymphoblastic leukaemia in relation to intake of vitamin and mineral supplements by the mother during pregnancy, and by the child before the reference date. Unmatched analyses

Supplement & details of use	Categories	No. of cases	No. of controls	Odds ratio (CI)
				Adjusted for age in years and sex only	Adjusted for age, sex, and other variables *
Mother's use during the pregnancy
Folic acid (any,	No	82	268
with or without iron)	Yes	8	27	0.9 (0.4–2.2)	1.1 (0.5–2.7)
Iron (any,	No	45	151
with or without folic acid)	Yes	44	142	1.1 (0.7–1.8)	1.2 (0.7–2.1)
Iron without folic acid	No	51	177
	Yes	38	116	1.2 (0.7–2.1)	1.3 (0.8–2.3)
Multivitamins	No	87	281
	Yes	3	14	0.7 (0.2–2.5)	0.8 (0.2–3.1)
Other vitamin or	No	78	263
mineral supplements	Yes	13	32	1.3 (0.6–2.6)	1.5 (0.7–3.1)
Child's use before the reference date †
Folic acid (any,	No	90	288
with or without iron)	Yes	6	15	1.2 (0.4–3.2)	1.0 (0.4–2.8)
Iron (any,	No	89	286
with or without folic acid)	Yes	7	17	1.2 (0.5–3.1)	1.1 (0.4–2.8)
Iron without folic acid	No	95	301
	Yes	1	2	1.3 (0.1–15.5)	1.6 (0.1–19.3)
Multivitamins	No	90	288
	Yes	6	15	1.2 (0.4–3.2)	1.0 (0.4–2.8)
Other vitamin or	No	82	272
mineral supplements	Yes	14	31	1.5 (0.7–3.0)	1.6 (0.8–3.4)

* Adjusted for age, sex, marital status, and mother's education.

† Restricted to child's use of a supplement for 5 or more days, either in a row or separate days. Child's usage in the six months prior to the diagnosis or reference date was not counted.