Persistent circulating unmetabolised folic acid in a setting of liberal voluntary folic acid fortification. Implications for further mandatory fortification?

Table 3 Unfasted group with outliers excluded.

	RCF (nmol/L)	PFOL (nmol/L)	PFA (nmol/L)	% PFA/PFOL	FA intake daily (μg)	FA intake in past 24 hours (μg)
Mean S.D.	1029.02 355.142	31.28 17.21	0.56 0.24	1.79	182.84 199.85	94.63 112.79
Median	1063.50	29.36	0.54		117.07	45.00
Minimum	356.00	5.13	0.08		0.00	0.00
Maximum	1778.00	72.71	1.05		962.30	500.00

Mean red cell folate, plasma total folate and unmetabolised folic acid concentrations in the blood donor group (n = 50).
RCF – Red cell folate
PFOL – Plasma total folate
PFA – Plasma folic acid
%PFA/PFOL – percentage of plasma folic acid to plasma folate
In table 2(b) two high outliers excluded for the purpose of statistical analysis are also excluded in this table.
FA intake daily (μg) – reflects typical daily folic acid intake from supplements and fortified foodstuffs.
FA intake in past 24 hours (μg) – reflects folic acid intake in the previous 24 hours from supplements and fortified foodstuffs.
Footnote: FA intakes daily and habitually show marked variability. This can be explained as follows. In attempting to capture habitual intakes a questionnaire similar to the food frequency questionnaire (which is a validated tool) was used. This questionnaire captures habitual intakes by documenting how much of the "nutrient of interest" is consumed per serving and typically on how days per week, month and then per year. The total amount is then divided by 365 to give a typical daily intake. Recent intakes are more easily captured as memory recall is not an issue and the intake data do not have to account for variability between days, weeks and months.

ISSN: 1471-2458