A comprehensive evaluation of food fortification with folic acid for the primary prevention of neural tube defects

Table 4 Laboratory data (geometric mean and 95% confidence interval) for senior participants (age 65 years or over) between Phase I and Phase II

Characteristic	Phase I	Phase II	P value ^‡
Total participants (n)	202	186
Serum folate (nmol/L)	14.8 (14.0 – 15.6)	23.0 (22.0 – 24.1)	<0.001
RBC folate (mol/L)	745 (713 – 779)	916 (873 – 961)^†	<0.001
Plasma HCY (μmol/L)	13.6 (13.0 – 14.2)^†	12.3 (11.7 – 12.9)^†	0.001
Serum vitamin B₁₂ (pmol/L)	183 (173 – 194)	216 (202 – 231)	<0.001
Plasma MMA (μmol/L)	0.24 (0.22 – 0.27)^†	0.26 (0.24 – 0.28)	0.229

† The Komogorov-Smirnov test showed that the log transformed data were non-normal (p < 0.05).
‡ P value for the difference between Phase I and Phase II is based on a non-parametric Mann-Whitney U test.
RBC denotes red blood cell, HCY denotes homocysteine and MMA refers to methylmalonic acid.

ISSN: 1471-2393