Table 4.

Mean and median plasma folate (nmol/L) in week 18 for the different patterns of maternal report of supplement use, n=2911.

	N	Mean	Median	Percentiles 25t/75th
(1) Use of supplements anytime in week 13 to 17
No supplements	1 119	8.49	6.77	4.89-9.79
Other supplements only	634	9.41	7.96	5.86-10.95
Folic acid only	211	16.04	12.89	8.06-21.43
Folic acid+	947	15.92	13.80	8.63-21.72
(2) Use of supplements anytime in week 9 to 12
No supplements	1 223	9.97	7.08	4.90-11.57
Other supplements only	234	9.99	7.08	5.16-12.35
Folic acid only	512	11.32	8.99	6.81-12.71
Folic acid+	942	14.43	11.77	7.90-19.03
(3) Use of supplements anytime in week -4 to 8
No supplements	1 180	9.25	6.84	4.79-10.79
Other supplements only	267	12.02	8.21	5.36-14.83
Folic acid only	526	12.22	9.51	6.86-14.66
Folic acid+	938	14.25	11.41	7.89-18.95
(4) Initiation of folic acid week -4 to 17
No folic acid	844	6.96	5.67	4.29-7.66
Start w -4-0	500	13.99	11.06	7.77-18.93
Start w 0-4	413	13.55	10.80	7.46-17.73
Start w 5-8	551	13.08	10.23	7.33-16.49
Start w 9-12	301	11.49	9.37	6.79-14.27
Start w 13-17	302	15.87	13.23	7.69-21.22
(5) Use of folic acid in every four week period
-4 to 17	238	17.17	15.72	9.37-23.10
(6) Use of folic acid in every four week period
-4 to 12	351	14.86	12.32	8.28-20.17