Folate intake and status among adults in the Netherlands

Objective: To assess the adequacy of folate intake and status among adults in the Netherlands. Design and subjects: Dietary in take was measured by 3 d diet records among 444 adults, aged 20-79 y, stratified for sex and 10 y age classes, with an overrepresentation of people with a low habitual intake of vitamin B6. Serum folate and other physical, biochemical and lifestyle characteristics were determined, and interrelationships were evaluated by bi- and multivariate regression analysis. Results: Mean folate intake was 325 and 308 μg/d in men aged 20-49 and 50-79 y, respectively. In both younger and older women mean folate intake was 270 μg/d. The prevalence of intakes below the lower limit of the recommended range (200-300 μg/d) was 10-20% among different age-gender groups. No intakes below the average minimum requirement of 100 μg/d were observed. The recommendation of 400 μg folate/d for women who wish to become pregnant was not met by 95% of the women aged 20-49 y. Potatoes, vegetables and fruit provided 36% of folate in the diet; other important sources were bread (18%) and dairy products (16%). Mean serum folate levels were 11.3 and 12.1 nmol/l in younger and older men, respectively. In younger and older women these levels were 12.2 and 14.2 nmol/l, respectively. Serum folate levels below 5 nmol/l (the 2.5 percentile of healthy blood donors) were present in 4% of the older men, but not in the other age-gender-groups. Serum folate levels were clearly influenced by recent folate intake. Furthermore, physiological and lifestyle variables, notably alcohol and tobacco use, were important determinants of serum folate. Conclusion: The folate intake among adult men and women was adequate in view of recommended daily intakes. However, the folate intake among women did not meet the recommendation for those who want to become pregnant. According to criteria derived from homocysteine metabolism as related to cardiovascular disease, folate status may not be adequate in 60-79% of adult age-sex groups.