Intake of vitamin C and E in pregnancy and risk of pre-eclampsia: prospective study among 57 346 women.
OBJECTIVE
It has been suggested that vitamin C, alone or in combination with vitamin E, may protect against pre-eclampsia, whereas the safety of high-dose vitamin E supplements has been questioned. We investigated dietary intakes of vitamins C and E to see if they correlated with the incidence of pre-eclampsia.


METHODS
Prospective cohort study.


METHODS
The Danish National Birth Cohort; a population-based pregnancy cohort; analyses were based on 57 346 pregnancies.


METHODS
Vitamin intake was estimated from a food frequency questionnaire completed in gestational week 25, recording intake from diet and supplements during the previous four weeks. Pre-eclampsia diagnoses were obtained from the Danish National Patient Registry; we worked with two entities, 'pre-eclampsia (all types)' and 'severe pre-eclampsia/eclampsia/HELLP'. We adjusted for confounding factors by logistic regression.


METHODS
A small increase in the incidence of severe disease was also seen in the group of women (64, n = 49 373) with a high intake of vitamin E from supplements and dietary sources.


RESULTS
The incidence of 'pre-eclampsia (all types)' did not correlate with dietary vitamin C and E intake. There was a decreasing trend (P = 0.01) in the incidence of 'severe pre-eclampsia/eclampsia/HELLP' with increasing dietary vitamin C intake; with an intake of 130-170 mg/day as reference, odds ratios ranged from 1.21 (95% confidence interval 0.83 to 1.75) for an intake below 70 mg/day to 0.70 (0.40 to 1.23) for an intake exceeding 275 mg/day (total n = 57 346). For vitamin E intake aggregated from diet and supplements (n = 49 373), with an intake of 10.5-13.5 mg/day as reference, the 'severe pre-eclampsia/eclampsia/HELLP' odds ratio was 1.46 (1.02 to 2.09) for an intake exceeding 18 mg/day.


CONCLUSIONS
Low dietary intake of vitamin C was associated with a trend towards an increased incidence of either severe pre-eclampsia, eclampsia or HELLP. A small increase in the incidence of severe disease was also seen in the group of women with a high intake of vitamin E from supplements and dietary sources.
Klemmensen
Ak
A
Maternal Nutrition Group, Danish Epidemiology Science Centre, Statens Serum Institut, Copenhagen, Denmark. klem@dadlnet.dk
Tabor
A
A
Østerdal
M L
ML
Knudsen
V K
VK
Halldorsson
T I
TI
Mikkelsen
T B
TB
Olsen
S F
SF
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D003718:Denmark / Q000453:epidemiology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D010298:Parity; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000517:prevention & control*; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D014810:Vitamin E / Q000008:administration & dosage*; D055815:Young Adult
D000975:Antioxidants; D014810:Vitamin E; D001205:Ascorbic Acid