Baseline investigations of folate status in Aboriginal and non-Aboriginal West Australians prior to the introduction of mandatory fortification

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.

Folate Status and Neural Tube Defects in Aboriginal Australians: the Success of Mandatory Fortification in Reducing a Health Disparity

Historically, neural tube defects (NTD) in Australia affected around 1 in every 1000 births; 42% higher for Aboriginal births. Following firm evidence of the protective effect of periconceptional folate, health promotion activities encouraged increased folate intake through diet and supplements and limited voluntary food fortification. A 30% reduction in NTD was observed in non-Aboriginal but not Aboriginal infants, widening the disparity between Aboriginal and non-Aboriginal rates. Mandatory flour fortification with folic acid in 2009, led to further reductions in overall NTD, and greater reduction among Aboriginal infants, such that rates in Aboriginal and non-Aboriginal infants were similar by 2010-2014. Elimination of this disparity will make a small but important contribution to the Australian government's Closing the Gap initiative to reduce disadvantage among Aboriginal people. Long-term, complete, high-quality surveillance data on NTD have been of great value in monitoring trends in and evaluation of public health interventions for NTD in Australia.

Folate status in Aboriginal people before and after mandatory fortification of flour for bread-making in Australia

BACKGROUND

Mandatory fortification of wheat flour for bread-making was introduced in Australia in September 2009, to assist in the prevention of neural tube defects (NTD). NTD are twice as common in Aboriginal compared with non-Aboriginal infants, and folate levels are lower in the Aboriginal population.

AIMS

This study was undertaken to compare folate status and NTD in the Aboriginal population before and after fortification.

METHODS

Postfortification, 95 Aboriginal men and nonpregnant women aged 16-44 years in metropolitan and regional Western Australia (WA) completed a rapid dietary assessment tool and had blood taken to measure red cell folate. Measures were compared with prefortification values obtained in an earlier study using the same methods. Data on NTD in Aboriginal infants were obtained from the WA Register of Developmental Anomalies.

RESULTS

No participant was folate deficient. The mean red cell folate increased after fortification to 443 ng/mL for males and 567 ng/mL for females. The mean difference between red cell folate after fortification compared with before was 129 ng/mL for males (95% CI 81-177); t = 5.4; P < 0.0001) and 186 ng/mL for females (95% CI 139-233); t = 7.9; P < 0.0001). Most participants ate fortified shop-bought bread at least weekly, resulting in an estimated additional folate intake per day of 178 (males) and 145 (females) dietary folate equivalents. NTD prevalence fell by 68% following fortification (prevalence ratio 0.32 (CI 0.15-0.69)).

CONCLUSIONS

The population health intervention of mandatory fortification of wheat flour for bread-making has had the desired effect of increasing folate status and reducing NTD in the Australian Aboriginal population.

Folate deficiency in an unselected population in Calgary, Alberta and its relationship with red blood cell macrocytosis

Background

Folate deficiency is rare in western countries and therefore blood tests for folate level have limited indications. One such indication is red cell macrocytosis, however it is unclear if the association of macrocytosis with folate deficiency is robust enough to serve as a risk marker. Our objective is to determine whether macrocytosis is a useful marker for folate deficiency.

Findings

Paired data from the Calgary Laboratory Services Information System was analyzed using receiver operating characteristic (ROC) curves to determine strength of association between mean corpuscular volume and serum folate. Strength of association was analyzed for serum folate cut-off values of 12, 10, 8, and 6 nmol/L. Overall, 0.2% of individuals were folate deficient (<6 nmol/L serum folate). Based on ROC curves, at each cut-off level, mean corpuscular volume was a poor predictive marker for serum folate level.

Conclusions

Folate deficiency is rare in Calgary, Alberta. Macrocytosis is not a strong predictor for folate deficiency.