Reproducibility and validity of a food frequency questionnaire among pregnant women in a Mediterranean area

Nutrition Journal

Table 4 Mean daily nutrient and food intakes by the ffq at week 12 ^th and nutrient plasma concentrations and pearson correlation coefficients in pregnant women of the Inma-Valencia study, 2004–2006

Nutrients and foods	FFQ1	Plasma concentration	Pearson coefficient correlations between FFQ1 and plasma concentrations		Agreement (%) ^c
Nutrients and foods	Mean	Mean (SD)	r ^a	r ^badj.
Retinol (μmol/l)	812	1.78 (0.54)	0.02	0.05	52.3
α- carotene (μmol/l)	536	0.15 (0.14)	0.31**	0.32**	61.9
β- carotene (μmol/l)	4499	0.40 (0.30)	0.21**	0.22**	58.8
Lutein + Zeaxanthin (μmol/l)	3157	0.32 (0.13)	0.26**	0.29**	60.1
Lycopene (μmol/l)	4410	0.72 (0.62)	0.05	0.04	52.3
β-cryptoxanthin (μmol/l)	360	0.22 (0.15)	0.26**	0.26**	62.3
Folate (mmol/dl)	305	80 (211)	0.06	0.12**	51.1
Diet + supplements (n=708) ^d	1616		0.53**	0.53**	72.0
Vitamin B12 (pmol/l)	9.9	322 (121)	0.08*	0.08*	55.3
Diet + supplements (n=740) ^d	12.0		0.11**	0.12**	55.0
Vitamin C (μmol/l)	144	50 (22)	0.16**	0.18**	57.4
Diet + supplements (n=520) ^d	157		0.18**	0.20**	58.3
Vitamin E (μmol/l)	11.4	33.2 (7.4)	0.01	0.05	52.6
Fruits and vegetables (g/day), mean (SD) vs	508 (260)		0.25**	0.28**	61.7
Carotenoids (μmol/l)^e		1.09 (0.56)

^a Nutrient intakes were log-transformed; ^b Adjusted for total energy intake and plasma carotenoids and vitamin E adjusted for total cholesterol; ^c Overall proportion categorized in the same or an adjacent quintile based on energy-adjusted intakes; ^d Total nutrient intake from diet and supplements. Folic acid from supplements were converted to dietary folate (0.6 μg from supplements =1 μg from diet); plasma concentration of vitamin C was available for 520 women; ^e Carotenoid in plasma included α-carotene, β-carotene, Lutein+Zeaxanthin, β- Cryptoxanthin; ^* P <0.05; ^** P<0.01.

ISSN: 1475-2891