Awareness, knowledge, and use of folic acid among non-pregnant Korean women of childbearing age

Neural tube defects (NTDs) such as spina bifida and anencephaly are common birth defects that contribute to infant mortality and disability [1]. They occur when the neural tube does not close completely within 28 days of conception. It is well established that adequate folate status of pregnant women is critical to prevent the occurrence of NTDs, and folic acid supplementation before pregnancy significantly reduces the risk of NTDs [2].

Since 1992, the United States Public Health Service has recommended that all women of childbearing age should consume daily supplements containing 400 µg of folic acid [3]. Currently, folic acid supplementation is officially recommended for women of childbearing age in many countries [4], and national campaigns have been implemented to increase the awareness and consumption of folic acid [5]. In addition, more than 50 counties have adopted mandatory folic acid fortification policies to prevent NTDs by improving the nutritional status of folate in women [6, 7].

Recent studies have shown that folic acid fortification reduces the prevalence of NTDs by an average of 46% [8], and the prevalence of spina bifida was reported to be significantly lower in countries with mandatory folic acid fortification policies than in those without such policies [9]. The prevalence of NTDs in countries with folic acid fortification policies is generally less than 10 per 10,000 births [10]. In Korea, an accurate estimate of the prevalence of NTDs remains unknown. However, when 10,868 Korean infants born in five local obstetric clinics from 2009 to 2010 were observed, the prevalence of NTDs was found to be 20.2 per 10,000 live and stillbirths [11].

Studies have shown that the folate nutritional status of Korean women of childbearing age is inadequate [12, 13]. Approximately 50% of Korean women of childbearing age do not meet the estimated average requirement for dietary folate, and 20% have serum folate concentrations of < 7 ng/mL [12, 13], which is the recommended concentration for effective prevention of NTDs [14]. In addition, according to the Korea National Health and Nutrition Examination Survey in 2007–2009, only 8.3% of women aged ≥20 years took folic acid or multivitamin supplements containing folic acid [15]. Therefore, adequate strategies to improve the nutritional status of Korean women and thus reduce the incidence of NTDs are needed.

Currently, no national folic acid campaigns have been conducted in Korea, and no policies for mandatory folic acid fortification have been implemented. The only existing program aimed at improving the folate nutritional status of Korean women provides folic acid supplements to pregnant women visiting public health centers [16]. However, this program is not effective in preventing NTDs since failure of neural tube closure occurs within 28 days of conception during which time most women do not realize they are pregnant. Therefore, it is important for women of childbearing age to be aware of the importance of folic acid and take folic acid supplements before pregnancy.

Factors influencing folic acid supplementation during pregnancy among Korean women include planned pregnancy, experience of previous spontaneous abortions, and knowledge of the importance of folic acid [17, 18]. However, there has been no published information on the factors associated with folic acid supplement use among non-pregnant Korean women of childbearing age. The purposes of this study were to investigate the awareness, knowledge, and use of folic acid supplements along with their associated factors among non-pregnant Korean women of childbearing age in order to explore our hypothesis that women with knowledge of folic acid are more likely to take folic acid supplements.

Our results show that only 9.4% of the women participating in this study took folic acid supplements despite the recommendation of the Korean Nutrition Society since 2010 that women of childbearing age should consume folic acid supplements [24]. Among women aged 19–24 years, only 2.8% took folic acid supplements. Significantly lower rates of folic acid use were observed in women aged 19–24 years (2.8%), unmarried women (4.1%), those with no prior pregnancy experience (4.8%), those at high risk of inadequate folate intake (5.8%), and unknowledgeable women (5.2%).

Multivariate analysis that investigated the factors associated with awareness and knowledge showed that women aged 25–34 years, college students, and married women were more likely to have heard of folic acid and have sufficient knowledge of folic acid compared with younger women, less educated women, and unmarried women, respectively. The highest odds of awareness and knowledge of folic acid were related to marital status. It is likely that many Korean women became aware of folic acid after marriage or pregnancy. In a previous study, the majority (97.9%) of pregnant Korean women were reported to have heard of folic acid, 72% had knowledge of folic acid, and 24.6% had experience taking folic acid supplements starting at least 1 month before conception [18]. These proportions were much higher than those of the non-pregnant women in this study. Since it was reported that approximately 50-60% of pregnancies are unplanned in Korea [17, 25], intervention to increase the awareness and knowledge of folic acid and use of folic acid supplements targeting young, less educated, and unmarried women is needed.

In many countries, educational campaigns aimed at promoting the use of folic acid as well as increasing awareness and knowledge of folic acid have been carried out [5]. In the US, national and statewide folic acid campaigns have been implemented since the mid-1990s. The proportion of women who had heard of folic acid steadily increased from 52% in 1995 to 84% in 2005 while that of women who knew that folic acid prevents NTDs increased from 4% to 19%; use of folic acid supplements increased from 28% to 33% during the same period [26]. In Australia, a national folic acid campaign began in 1997. The proportion of women of childbearing age who knew of the role of folic acid in preventing NTDs increased from 25.5% in 1994 to 77.0% in 2007, that of women who knew the appropriate time for use increased from 11.5% in 1994 to 38.9% in 2007, and that of women who took folic acid supplements increased from 37.2% in 1998 to 63.7% in 2007 [27].

Chivu et al. [28] conducted a systematic review of 31 studies designed to increase the awareness, knowledge, and use of folic acid before and during pregnancy and concluded that folic acid awareness increased from 60% to 72%, knowledge from 21% to 45%, and consumption from 14% to 23% due to interventional strategies. In 2009, a large cross-sectional survey of women aged 15–49 years in 18 European countries was conducted [29]. Overall, 70% of women had heard of folic acid, 17% knew that folic acid can reduce the risk of NTDs, and only 7% took folic acid supplements at the time of survey, although many European countries had implemented educational campaigns using different channels [5].

The gaps between awareness, knowledge, and use of folic acid could be explained by difficulties in behavioral changes. Many factors contribute to behavioral changes associated with use of folic acid supplements. Low use of folic acid supplements was reported to be associated with lack of pregnancy intention, high cost of folic acid tablets, forgetfulness, and lack of knowledge [30, 31, 32]. Incomplete outreach, lack of prior awareness and knowledge, unplanned pregnancy, and personal characteristics such as age and educational level were identified as barriers to the success of folic acid public health campaigns [33].

Prior findings that folic acid supplement users had much higher concentrations of plasma folate and red blood cell folate than non-users support the effectiveness of folic acid supplement use for improving folate nutritional status [19]. In a Japanese case control study, folic acid use was found to be associated with a reduced risk of spina bifida births, and knowledge about the preventive role of folic acid was associated with increased folic acid use [20].

In our study, we could not perform multivariate logistic analysis to determine whether knowledge is the most important factor affecting use of folic acid supplements since only 9.4% of women took folic acid supplements. Instead, supplementation rate was compared between knowledgeable women and unknowledgeable women. Overall, 22.8% of women with knowledge took folic acid supplements, whereas only 5.2% of women without knowledge did (Fig. 1). In addition, for each age, education, and marital category, knowledgeable women were more likely to take folic acid supplements than unknowledgeable women. These results support our hypothesis that women with knowledge of folic acid are more likely to take folic acid supplements. Therefore, education regarding folic acid is important, although educational campaigns seem to be generally ineffective in increasing the use of folic acid in other countries. As the most common source of information on folic acid is the media (22.7%), health professionals should try to provide reliable information about folic acid through the media.

The limitation of this study is that the educational level of the participants was relatively high. Therefore, the percentage of Korean women who knew of folic acid may be lower than that obtained in this study. In addition, some of the women who took multivitamins containing folic acid might not have intended to improve their folate nutritional status for an increased chance of getting pregnant. To the best of our knowledge, this is the first report regarding the awareness, knowledge, and use of folic acid among non-pregnant women in Korea. The results of this study may provide opportunities to promote interest in the development of folic acid campaigns. It would be necessary to organize campaigns to improve the knowledge regarding the importance of folic acid and to promote consumption of folic acid supplements as well as folate-rich foods targeting young, less educated, and unmarried women.