This review focused on geophagia health education and promotion intervention studies conducted worldwide.

The researcher and the research team separately reviewed journal articles according to the titles, abstracts and intervention type. They all scrutinised the studies to ensure their compliance with the set criteria for inclusion. Studies that qualified to be included in this review were those that assessed geophagia health education and promotion interventions. These studies were published in English with full in text open access. The research team held meetings to discuss potential discrepancies during the review in order to reach agreement on the interpretation of the criteria for selection. The screening of journal articles took place in two stages. In the first stage the reviewers separately assessed the titles and abstracts of all the retrieved citations against set inclusion criteria outlined in table 2. Where articles were deemed pertinent by one or more of the reviewers, they were presented to all the reviewers in order that agreement could be reached for those articles to be included in the full text review. Articles were also screened to allow the removal of duplicates from different databases according to their titles and abstracts. Duplicate articles were deleted, and the remaining articles that did not meet the set criteria were also excluded. The articles that satisfied the eligibility criteria for inclusion were reviewed in full (See Table 3). In case the reviewers differed, a resolution was taken through discussion or third-party consultation where necessary. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart template was used to perform the study selection process. See Figure 1.

A data extraction framework was developed to guide the eligible full texts retrieved in the literature review, based on the initial scoping phase. Since the researcher and research team served as reviewers, each one used a standardised data extraction form separately to draw from the articles that were considered for inclusion. A table was drawn to include information on geophagia health education and promotion interventions to mitigate the practise of geophagia, the methodology used, the sample size and population group of interest. The important information that was covered by the form included the design of the study, the year of publication, the title, the geophagia health education and promotion interventions investigated, the country where the study was conducted, and the main findings. For consistency, all reviewers scheduled a pilot test of the studies included, and the categories that needed to be amended or merged. Where reviewers differ in their opinions, an intervention discussion amongst the team was convened to reach an agreement.

A narrative synthesis was used to summarise the existing literature on geophagia health education and promotion interventions and to propose the most effective strategies to curb and mitigate the practise in order to reduce the incidence of maternal, neonatal and childhood mortalities and morbidities. This review provided a thematic overview of the findings of the studies that have investigated geophagia health education and promotion interventions. The studies were summarised, interpreted and reported, using a standardised tool, to add to the body of relevant knowledge. In addition, gaps in the existing literature were identified in order to be able to make pertinent suggestions about future research topics. The findings of this review could be used to inform policy formulation and strategy development for campaigns aimed at persuading people to quit engaging in geophagia. Furthermore, the findings of this study could be used to inform the development of health education and promotion awareness programmes aimed at mitigating the effects of geophagia.

To minimise risk of bias, this review used PRISMA reporting template to select and include studies in this review to minimise risk to bias. This is a flow diagram checklist is used to minimise risk of bias, since it outlines on screening processes followed, how studies were searched, screened, included and reasons for inclusions. This tool offers benefits such as transparency, and replication.

Since this review was based on publicly available publications and materials, no ethical approval was required.

Studies reveal that public health education on the uptake of iron and folic acid supplements during pregnancy has effectively reduced the practise of geophagy amongst women of reproductive age [50, 51]. Women of reproductive age who attend public health education on the uptake of iron and folic acid supplements are more likely to make healthy pregnancy choices than those who lack proper knowledge and understanding of the iron and folic acid supplements [50–52]. Public health education on the uptake of iron and folic acid supplements should be considered on different platforms to lessen the practise of geophagy [16, 51].

A study recommends a community-based health education programme on knowledge and attitudes towards iron and folic acid supplementation amongst pregnant women as an intervention strategy that could be employed to curb the practise of geophagy amongst pregnant women [53]. The offering of nutrition education as part of the community-based health education on knowledge and attitudes towards iron and folic acid supplementation has been reported to be effective in mitigating the practise of geophagy amongst pregnant women [29, 36, 51].

Community nutrition education targeting geophagy is one of the initiatives that could be used to mitigate the practise of geophagy [54]. It is reported that many geophagic women lack proper knowledge and understanding of their physiological and nutritional needs, particularly their needs when pregnant [27–29, 36]. Pregnant women are taught about the correct food choices, plans and diets that will promote their pregnancy outcomes during their consultation in the antenatal care service units, but the topic of geophagy has never raised [15, 41, 51]. The delivery of geophagy health education by healthcare workers and dieticians to geophagic women of reproductive age is pivotal to preventing iron deficiency anaemia, which is usually linked to the practise of geophagy [15, 36, 55, 56].

Another intervention method that could be used to prevent and control geophagy would be the implementation of health education about anaemia risks and geophagy to promote pregnancy outcomes at antenatal care units for pregnant women as the major consumers of clay soil [15, 51, 55, 56]. Educating pregnant women at the antenatal care units could minimise the risk of them developing iron deficiency anaemia and could reduce the practise of geophagy amongst pregnant women and the public at large [4, 7, 18, 51].

Studies have indicated that educating women about the harmful effects of geophagy at the antenatal care units can be employed as one of the health education intervention programmes aimed at preventing, controlling, and treating the practise of geophagy amongst pregnant women [1, 18, 27, 57]. The concept of geophagy would be explored and taught to pregnant women at a deeper level to capacitate these women to take informed decisions when it comes to the practise of geophagy [7, 17, 23, 58]. The incorporation of geophagy in the nutrition health education package would assist in decreasing the practise amongst pregnant women [1, 2, 23, 57]. A study emphasises the need for healthcare workers to intensify health education on geophagy and its associated negative health effects on pregnant women and the foetus in all trimesters of gestation [2].

Studies recommend the provision of education on the potential health risks associated with the chemicals found in clay, to educate geophagic women about the dangerous health-related risks and outcomes resulting from the toxicological aspects of the practise of geophagy [5, 17, 23, 43, 59]. Potential health risks education on the chemicals found in clay soil at community, school, and public healthcare level offers a crucial opportunity to decrease the practise of geophagy [4, 59].

The health promotion interventions aimed at preventing, controlling, and treating the practise of geophagy include the administration of oral iron and intravenous therapy [42]. Oral iron therapy is often administered to pregnant women at the antenatal care units and sold over the counter from pharmacies to the general public [14, 25, 36, 42]. Other studies report that many pregnant women with a history of practicing geophagy are often faced with challenge of iron deficiency anaemia, which necessitates the need for intravenous iron therapy post childbirth [14, 27, 35, 49].

Studies have shown that the replacement of clay soil with food items could aid in reducing the practise of geophagy [28, 36]. Adolescent women were encouraged to eat any snack or food item whenever they experienced the urge to ingest clay soil [28, 60, 61]. This intervention has yielded positive results, proving to be effective in decreasing the practise of geophagy amongst women of reproductive age [13, 28, 36]. Most of the adolescent women who were participants in this intervention programme reported that they had managed to quit geophagy [28, 60, 61]. Additionally, it was reported that the desire to practise geophagy had literally disappeared after replacing the clay soil with a food item each time they felt the craving [28, 36].

Offering pregnant women folic acid and iron supplements is one of the health interventions that is aimed at promoting maternal and child health [31, 41]. Anaemia amongst women of reproductive age is of public health importance [60, 61]. Preventative and control measures of anaemia amongst women of reproductive age such as the provision of folic acid and iron supplements at antenatal care are presently among the methods used to minimise the practise of geophagy [14–16, 31, 42], however, some women do not consume folic acid and iron supplements after collection in from the antenatal care units [16, 35, 50, 62].

There are nutrition and health education programmes that are presently being implemented at school level to facilitate awareness amongst pupils [12, 60, 61, 63]. The addition of folic acid and iron supplementation as part of the health education programme has been identified as one of the key initiatives that could be considered to promote the mitigation of the practise of geophagy amongst women of reproductive age [60, 63–65]. This intervention programme targets adolescent women at secondary schools, where health education about anaemia, menstruation, iron nutrition and geophagy are covered as among the main topics that need to be addressed [60, 66, 67]. This intervention has generated positive results in terms of adolescent women quitting the practise of geophagy [12, 61].

Other studies advocate the removal and pre-treatment of toxic elements found in clay soil that is eaten by geophagic women of reproductive age to prevent possible detrimental health complications [1, 5, 59]. The removal of the toxic elements found in clay soil before its sale would not contribute to the decline of geophagy amongst women of reproductive age, but it would reduce the level of toxicity, which often leads to serious health problems [1, 5, 17, 59]. Another study recommends the biomonitoring of clay soil consumers, particularly of women of reproductive age, to confirm the suspected health effects of the geophagic practise [5].

Studies have stressed the need for more research pertaining to the practise of geophagy to fully understand the etiology, physiological, nutritional, psychological, medical and spiritual impact of the practise amongst women of reproductive age, with an emphasis on pregnant women as the identified vulnerable group [7, 20, 30]. A multi-disciplinary research project would bring together different disciplines to address the practise of geophagy as a societal problem [7, 20]. If more multidisciplinary research were to be conducted pertaining to the practise of geophagy, the public would have more access to evidence-based information that could be used to inform their decisions when it comes to the practise of geophagy.