Folate status and socio-demographic predictors of folate status, among a national cohort of women aged 26-36 in Australia, 2004-2006

Main sources and predictive factors of folate intake in female university students

OBJECTIVE

The study aimed to identify the main folate sources and examine socio-demographic and lifestyle determinants influencing folate intake among 1410 women aged 18 to 39.

METHODS

Data were collected using a self-administered health and lifestyle questionnaire and a 5-d dietary record method. To assess folate intake in relation to the dietary reference intakes, the probability approach was used. Folate intake determinants were identified using multivariate-adjusted logistic regression models; odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

The average total folate intake among women was 311 ± 144 µg/day dietary folate equivalents. Vegetables (30.7%) and cereals (22.6%) were the most important folate sources. Foods fortified with folic acid were consumed by 20.6% of women, dietary supplements by 7.2%. More than half of the participants (55%) had a high probability of inadequate folate intake. The predictors of being in the highest tertile of folate intake (>303 versus <225 µg) were: physical activity (high versus low; OR: 2.97, 95% CI: 1.77-4.97), nutritional knowledge (high versus low; OR: 5.32, 95% CI: 2.82-10.1), following a vegetarian diet (yes versus no; OR: 6.13; 95% CI: 2.79-13.5), daily number of meals (≥5 versus ≤3; OR: 4.17, 95% CI: 2.38-7.32), excluding/including some foods (yes versus no; OR: 2.47; 95% CI: 1.41-4.31) and energy intake (3rd versus 1st tertile; OR:17.4, 95% CI: 11.1-27.4).

CONCLUSION

Identifying factors associated with a higher intake of folate may be helpful in shaping public health nutrition policy. It allows the design of effective nutrition education programs to promote increased intake of folate in subgroups at risk of deficiency.

Folic acid deficiency declined substantially after introduction of the mandatory fortification programme in Queensland, Australia: a secondary health data analysis

OBJECTIVE

To investigate the prevalence of folic acid deficiency in Queensland-wide data of routine laboratory measurements, especially in high-risk sub-populations.

DESIGN

Secondary health data analysis.

SETTING

Analysis of routine folic acid tests conducted by Pathology Queensland (AUSLAB).

PARTICIPANTS

Female and male persons aged 0-117 years with routine folic acid testing between 1 January 2004 and 31 December 2015. If repeat tests on the same person were conducted, only the initial test was analysed (n 291 908).

RESULTS

Overall the prevalence of folic acid deficiency declined from 7·5 % before (2004-2008) to 1·1 % after mandatory folic acid fortification (2010-2015; P < 0·001) reflecting a relative reduction of 85 %. Levels of erythrocyte folate increased significantly from a median (interquartile range) of 820 (580-1180) nmol/l in 2008 before fortification to 1020 (780-1350) nmol/l in 2010 (P < 0·001) after fortification. The prevalence of folic acid deficiency in the Indigenous population (14 792 samples) declined by 93 % (17·4 v. 1·3 %; P < 0·001); and by 84 % in non-Indigenous residents (7·0 v. 1·1 %; P < 0·001). In a logistic regression model the observed decrease of folic acid deficiency between 2008 and 2010 was found independent of gender, age and ethnicity (ORcrude = 0·20; 95 % CI 0·18, 0·23; P < 0·001; ORadjusted = 0·21; 95 % CI 0·18, 0·23; P < 0·001).

CONCLUSIONS

While voluntary folic acid fortification, introduced in 1995, failed especially in high-risk subgroups, the 2009 mandatory folic acid fortification programme coincided with a substantial decrease of folic acid deficiency in the entire population.

Low proportions of folic acid deficiency after introduction of mandatory folic acid fortification in remote areas of northern Queensland, Australia: a secondary health data analysis

Background: Australia implemented mandatory folic acid fortification of bread-making flour in 2009. Objective: To assess the impact of folic acid fortification in remote vs. regional urban areas and Indigenous vs. non-Indigenous populations in northern Queensland. Methods: Routinely collected data on folic acid measurements in remote areas and two regional urban centres in northern Queensland between 2004 and 2015 were analysed (n = 13,929) dichotomously (folic deficient vs. non-deficient). Results: Overall prevalence of folic acid deficiency was 3.2% (235/7282) in urban centres compared with 7.2% (480/6647) in remote areas (p < 0.001), and 9.3% (393/4240) in the Indigenous population compared with 3.2% (273/8451) in the non-Indigenous population (p < 0.001). Prevalence of folic acid deficiency dropped from 12.2% (n = 481) in 2004-2008 to 1.5% (n = 126) in 2010-2015 (p < 0.001). This translates into a relative risk reduction (RRR) of 88%. RRR was 79% (7.2% vs. 1.5%) in urban centres, 91% (17.3% vs. 1.5%) in remote areas, 92% (20.5% vs. 1.6%) in the Indigenous population and 80% (7.4% vs. 1.5%) in the non-Indigenous population (p < 0.001 for all). Conclusions: Substantial declines of folic acid deficiency to low and comparable proportions in former high-risk populations indicate that mandatory folic acid fortification of flour has had a population-wide benefit in northern Queensland.

Predictors of folate status among pregnant Japanese women: the Hokkaido Study on Environment and Children’s Health, 2002–2012

The International Clearinghouse for Birth Defects, Surveillance and Research reports a rise in the prevalence rate of spina bifida in Japan. We determined first-trimester folate status of Hokkaido women and identified potential predictors. Participants were 15 266 pregnant women of the Hokkaido Study on Environment and Children’s Health Cohort. Data were extracted from self-reported questionnaires and biochemical assay results. Demographic determinants of low folate status were younger maternal age (adjusted OR (AOR) 1·48; 95 % CI 1·32, 1·66), lower educational level (AOR 1·27; 95 % CI 1·17, 1·39) and lower annual income (AOR 1·11; 95 % CI 1·01, 1·22). Plasma cotinine concentrations of 1·19–65·21 nmol/l increased the risk of low folate status (AOR 1·20; 95 % CI 1·10, 1·31) and concentrations >65·21 nmol/l further increased the risk (AOR 1·91; 95 % CI 1·70, 2·14). The most favourable predictor was use of folic acid (FA) supplements (AOR 0·19; 95 % CI 0·17, 0·22). Certain socio-demographic factors influence folate status among pregnant Japanese women. Modifiable negative and positive predictors were active and passive tobacco smoking and use of FA supplements. Avoiding both active and passive tobacco smoking and using FA supplements could improve the folate status of Japanese women.

[Folic acid intake before and after mandatory fortification: a population-based study in São Paulo, Brazil]

This study analyzed folic acid intake before and since mandatory fortification. Dietary data were collected by 24-hour recall in a health survey in São Paulo (ISA-Capital) in 2003 and 2007-2008, stratifying the population according to life stage and gender. Estimated average requirement (EAR) and tolerable upper intake level (UL) were used to assess intake. Prevalence of inadequate folic acid intake decreased in all groups, especially adolescents and adult males (72% to < 1% and 76% to 6%, respectively) but remained high in adult women (38%). Beans were the main source of folic acid before fortification. With fortification, bread became the main source, but beans remained important. Fortification was successful (increased intake within safe levels), but it raised concerns about the high proportion in the target group (adult women) who still fail to meet the recommended intake.

Socioeconomic factors are associated with folate and vitamin B12 intakes and related biomarkers concentrations in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence study

Because socioeconomic factors (SEFs) may influence dietary quality and vitamin intakes, this study aimed to examine associations between socioeconomic factors and folate and vitamin B12 intakes as well as their related biomarkers in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. Vitamin intakes were obtained from two 24-hour recalls in 2253 participants (47% males). Vitamin B biomarkers were assessed in a subsample of 977 participants (46% males). Socioeconomic factors were assessed by questionnaire, and 1-way analysis of covariance and linear regression analysis were applied. For males and females, mean intakes of folate were 211.19 and 177.18 μg/d, and for vitamin B12, 5.98 and 4.54 μg/d, respectively. Levels of plasma folate, red blood cell folate, serum B12, and holotranscobalamin were 18.74, 807.19, 330.64, and 63.04 nmol/L in males, respectively, and 19.13, 770.16, 377.9, and 65.63 nmol/L in females, respectively. Lower folate intakes were associated with several SEFs, including maternal and paternal education in both sexes. Regarding folate biomarkers, lower plasma folate intakes were associated with single/shared care in males and with lower paternal occupation in females. Lower vitamin B12 intakes were associated with almost all the studied SEFs, except paternal occupation in both sexes. In females, when considering vitamin B12 biomarkers, lower plasma vitamin B12 was associated with lower maternal education and occupation, and lower holotranscobalamin was associated with lower maternal education and lower paternal occupation. In conclusion, from the set of socioeconomic determinants studied in a sample of European adolescents, maternal education and paternal occupation were more consistently associated with folate and vitamin B12 intakes and biomarkers concentrations.

Intake and blood concentrations of folate and their association with health-related behaviors in Korean college students

The purpose of this study is to assess folate intake, and serum and red blood cell (RBC) folate concentrations, and investigate the association between folate status and health-related behaviors among Korean college students. A total of 169 students, aged between 18 and 27 years, participated in this study. Dietary intake data were collected by trained interviewers using a 24-hour recall method for three non-consecutive days in 2009. Information on health-related behaviors was obtained by a self-administered questionnaire. Serum and RBC folate concentrations were measured by microbiological assay. The average intakes of folate were 456 µgDFE and 347 µgDFE in male and female students, respectively. While the average serum folate concentration was significantly lower in male students (8.9 ng/mL) compared to female students (12.5 ng/mL), RBC concentrations were not significantly different between male (398.6 ng/mL) and female students (405.3 ng/mL). In male students, low serum folate concentrations were associated with total folate intake less than the Estimated Average Requirement, non-use of folic acid supplements, smoking, alcohol drinking at least once a week and low physical activity. In female students, low serum folate concentrations were associated with smoking and alcohol drinking at least two drinks at a time and BMI ≥ 25. Alcohol drinking and low physical activity were also associated with low RBC folate concentrations in both male and female students. In order to improve folate nutritional status of college students, the practice of desirable health-related behaviors, such as non-smoking, moderate alcohol drinking, regular physical activity, and maintenance of healthy BMI should be encouraged along with consumption of folate-rich foods and supplements.