Understanding micronutrient supplementation: evidence from literature

High prevalence of anemia among pregnant women is reported in Africa despite the availability of effective interventions to prevent anemia during pregnancy. A number of studies put the prevalence of anemia in pregnancy within Africa at between 57 and 86 % [10–12, 19, 29–35]. This is blamed on both nutritional deficiency and infections. An editorial in 2001 noted that nutritional deficiency contributes 32 %. A study in eight rural districts of Ethiopia revealed that women lacked comprehensive knowledge of anemia [36].

Given the widespread prevalence of micronutrient deficiencies in developing countries, supplementation with multiple micronutrients rather than iron-folate alone could be of potential benefit to the mother and the fetus. Haider et al. evaluated evidence from 17 articles on impact of multiple micronutrient supplements during pregnancy compared with standard iron-folate supplements on specific maternal and pregnancy outcomes of relevance to the Lives Saved Tool (LiST) [37, 38]. The results show that there is no significant difference between the multiple supplementation and iron supplement alone.

Yakoob et al. conducted a systematic review of published randomized and quasi-randomized trials on PubMed and the Cochrane Library as per the CHERG guidelines [28]. They concluded that there is a paucity of studies of intermittent iron of iron-folate supplementation, especially in developing countries. They thus recommended further evaluation of this intervention in comparison with daily supplementation regimes.

A cross-section study in Mali, to assess pregnant women’s acceptability of and adherence to a daily multiple micronutrient supplementation scheme compared with the current daily iron and folic acid supplementation scheme, revealed that women started receiving supplements at the end of the first trimester of pregnancy until delivery. Adherence to the multiple micronutrient supplementation scheme was better than that to the iron and folic acid supplementation scheme. However, both were very good, as were women’s perceptions about the benefits of micronutrient supplements to their health and that of their newborns [39].

Ogundipe et al. assessed the factors associated with prenatal folic acid and iron supplementation among 21,889 pregnant women in Northern Tanzania, employing cross-sectional hospital-based data [40]. They observed that folic acid and iron supplementation were low among the women in Northern Tanzania. They identified certain factors as positively associated with folic acid supplementation to include advanced maternal age, unknown HIV status, and being diagnosed positive of anemia.

Miller et al. examined the impact of agricultural practices on micronutrients in the food supply, including cropping systems, soil fertility, and animal agriculture [41]. They also explored successful strategies to preserve micronutrients from farm to plate, including food fortification. The exercise ended with recommendations for actions that will reduce the prevalence of micronutrient malnutrition.

Darnton-Hill et al. conducted a review of literature to identify the micronutrients (vitamins and minerals) likely to be deficient in women of reproductive age in low- and middle-income countries (LMIC), especially during pregnancy, and the impact of such deficiencies [42]. In a theoretical paper on micronutrient in pregnancy, Black enumerated the many consequences of micronutrient deficiency in pregnancy and recommended additional research on the prevalence of such deficiencies and their consequences and on cost-effective public health interventions for their control [43].

In a cross-sectional study, Shipala et al. assessed the adequacy of nutrient intake including proteins, energy, calcium, iron, folate, and vitamin C and identified the factors associated with nutrient intake in Kenya [44]. The results revealed that intake of all selected nutrients were significantly lower than the required dietary allowance. Protein intake was significantly associated with education, income, and perceived food shortage. Energy intake was significantly associated with income. Iron intake was significantly associated with perceived food shortage. Similar studies by Gomez et al. in a cohort of Alberta pregnant women and Horan et al. in their ROLO study and Christian et al. in rural Nepal highlight the need for both dietary and supplemental sources of micronutrients when assessing the nutrient intakes of pregnant women [45–47].

The common feature of all the studies is the heavy dependence on statistical approach with limited qualitative data that provides the rich context of the behavior of the women vis-à-vis compliance with the recommended micronutrient uptake during pregnancy. This present study employed the mixed method approach in collection of data from women in different environments, namely rural, peri-urban, and urban settings. The adoption of the mixed-method approach provided opportunity for the exploitation of the rich synergy in triangulating information from qualitative and quantitative methods of inquiry.

Study design

The study was designed for description and analysis of the knowledge levels, attitudes, and practices concerning anemia during pregnancy, using mixed methods in urban, peri-urban, and rural communities. The study combined two analytical designs, namely (1) a cross-sectional survey and (2) qualitative inquiry. The survey research was based on an interviewer-administered household survey instrument while the qualitative inquiry was based on in-depth interviews and focus group discussion methods. These two designs contribute to an in-depth, triangulated understanding of community knowledge, attitudes, and practices on anemia during pregnancy in Southeast Nigeria.

Study settings, population, and sampling

The Nigerian political structure comprises of 36 states and the Federal Capital Territory distributed into six geopolitical zones (GPZs). See Fig. 1. These GPZs are made up of states with semi-autonomous health systems that independently develop strategies for attaining health targets, in line with the national health policy. The GPZs represent broad clusters of political, cultural, and linguistic realities in Nigeria. They are the fundamental context for understanding Nigeria’s ethnic diversity. The realities, represented by this spread, go a long way to influence the health services and behavior of the people. The South East GPZ (comprising of five states) is predominantly Igbo, one of the three largest ethnic-sociocultural groups in Nigeria. Beyond being culturally homogenous, the zone is well known to the researcher. Beyond being culturally homogenous, the zone had the highest average zonal immunization coverage on all basic vaccines for children (51.7 %) in 2013, although the value is below the desired 80 % expected at the local government area (LGA) levels. The other zones—South West, South-South, North Central, North East, and North West—had average zonal coverage of 40.9, 52.0, 26.9, 14.2, and 9.2 %, respectively [4].

States in the South East GPZ were grouped into two categories of “strong” (well performing) versus “weak” (less well performing) based on immunization coverage with all basic vaccines for children, as a reflection of the PHC development at the state and LGA levels, which has implication for health awareness and behavior of mothers during pregnancy. The zonal average all basic vaccination coverage for the South East was 51.7 %. Thus, any state within the zone with less than the zonal average was classified as weak. Imo State, with 62.4 is classified as “strong,” while Abia (49.8 %), Anambra (51.6 %), Ebonyi (51.1 %), and Enugu (45.0 %) were classified as “weak.” Imo is purposively selected to represent the strong health system while Enugu State was randomly selected from cluster of weak performing states.

Enugu State is located between latitude 6°30′ N and longitude 7° 30′ E. It is a mainland state in southeastern Nigeria (http://en.wikipedia.org/wiki/Enugu_State). Its capital is Enugu in Enugu North LGA. Carved out of the old Anambra State in 1991, the principal cities in the state are Enugu, Udi, Oji, and Nsukka. The state shares borders with Abia and Imo States to the South, Ebonyi State to the East, Benue State to the Northeast, Kogi State to the northwest, and Anambra State to the West. The 2006 population census put Enugu State population at 3,257,298 [48]. With an annual growth rate of 2.35 %, the 2015 population of Enugu State was put at 4,014,654 persons. Approximately 50 % (50.1 %) is made up of women, out of which 43.9 % fall within the child bearing age of 15–49 years.

University of Nigeria Teaching Hospital (UNTH) is located in Enugu State, as is the Enugu State University Teaching Hospital and College of Medicine. In addition to numerous private hospitals and clinics in the state, there are seven district hospitals in Enugu Urban, Udi, Agbani, Awgu, Ikem, Enugu-Ezike, and Nsukka. There are 46 government-owned health facilities located in seven health districts.

Imo State lies between latitude 4°45′ and 6°15′ N and longitude 6°30′ and 8°09′ E and is bounded by Abia and Anambra States on the North. Rivers and Bayelsa States bound it in the South. Imo State has an estimated total population of about 4,849,311 million persons in 2015 based of 2006 population figure of 3,934,499, with 27 local government areas. Imo State is culturally distinct area with a remarkable health seeking behavior. There are a number of health institutions that provide primary, secondary, and tertiary health care in the state.

The primary unit of analysis for this study is all mothers of child bearing age (15–49 years). It focused in understanding the practices to prevent anemia during pregnancy. It is noted that iron status can be enhanced by including iron supplements in foods consumed by women, improving women’s diets, and controlling intestinal parasites. In Nigeria, only 21 % of women take iron tablets daily for 90 or more days during their last pregnancy. In Enugu and Imo States, only 64.7 and 47.8 % respectively did so. The southeast zonal intake of iron tablets for 90 or more days was 38.3 % [4].

The LGAs in each of the two selected states will be classified and grouped into three clusters of rural, urban, and peri-urban. Three LGAs, one each from the urban, peri-urban, and rural segments of each sampled state, were randomly selected. From the list of communities in each sampled LGA, two communities were randomly selected. These communities formed the sampling clusters from which eligible respondents, who delivered within 6 months preceding the survey, were drawn, following a two-stage sampling. The communities were grouped into two clusters of far (>5 km) and near (<5 km) to the LGA PHC center. One community was randomly selected from each cluster, yielding a total of 12 communities.

Using a 40.4 % rate of occurrence of anemia in pregnancy in southeastern Nigeria [12] and a confidence interval of 95 % with an estimated 2.5 % level of precision, a sample size of 1480 ± 37 respondents was computed in the communities. However, the sample size was rounded up to 1500 households, taking into account a 1 % contingency rate. Approximately 125 women were interviewed in each of the 12 communities.

To select the households, a central location in each of the randomly selected communities was identified to serve as the starting point for data collection in the selected community. Two data collectors were assigned to cover each community cluster and the interviewers moved in opposite directions from the identified starting point in each community. Interviewers continued to turn right at every junction, until the desired number of respondents is attained.

Research instruments

A structured interview schedule (other-administered questionnaire) constituted the main instrument for data collection. It covered information on the socio-demographic characteristics of the respondents as well as their child bearing experiences. It also provided data on the women’s experiences with the PHC as well as their knowledge, attitude, and practice concerning anemia during pregnancy among others. The questionnaire consisted mainly of close-ended questions with lists of optional responses from which the respondents chose their responses. However, given the focus of the study to ascertain the knowledge, attitude, and practices of the respondents on anemia, they were not allowed prior knowledge of the content of the questionnaires; hence, the other-administered approach was used. The respondents gave their answers as they considered best. Where the answers they gave did not fall within the options, the responses were classified under “others.”

Some qualitative data were collected with the use of focus group discussion (FGD) and in-depth interview (IDI) guides. The FGD and IDI explored people’s opinion, perceptions, and attitudes toward anemia during pregnancy. They contained open-ended guide questions with probes providing wider exploration of the opinions, perceptions, and attitudes expressed by respondents to IDIs and participants in FGD sessions.

The FGDs were health with the husbands and mothers of the women aged 15–49 years, who delivered babies within 6 months preceding the study. There were a total of six FGDs for husband and six FGDs for mothers of the women who delivered within 6 months preceding the study. Each FGD session consisted of 8 to 12 participants. These were the primary support and significant others to the women who delivered within 6 months preceding the study. They are privileged to know practices of the women during their pregnancy and delivery. It was not possible to get sufficient number of the women, who delivered within 6 months preceding the study, to a convenient place for FGD. Thus, their husbands and mothers served as proxy.

On the other hand, IDI were held with persons in charge of the health facilities in the communities. A total of six IDI sessions were held with the health workers. Being the providers of health care, especially ANC services in the communities, they possessed knowledge of the actual practices and attitudes toward anemia in pregnancy among women of child bearing ages in the communities.

Statistical analysis

Data management and analysis were performed using EPI Info version 6.04d and the statistical package for social sciences (SPSS) version 22. Statistical significance was assessed using two-tailed tests. All p values less than 0.05 were considered to be statistically significant. Knowledge scores were assigned to each participants corresponding with the number of correct answers on knowledge questions. The numeric scores were tabulated for various groups and then re-categorized as binary variables, either greater than or less than the mean knowledge score. Similar actions were taken to derive both the attitude and practice scores.

Categorical variables were presented as frequencies and percentages. Chi-square (χ ²) tests were used to assess the statistical association between variables. Mean scores of anemia in pregnancy knowledge, attitudes, and practices were compared among socioeconomically different communities as well as population with varying demographics. Binary logistic regression analyses were used to adjust for known covariates. Bi-variate association analyses were used to select the candidate-associated factors for the multivariate logistic regression. The multi-categorical variables were converted to dummy variables to calculate odds ratio of each value. The principal component analysis (pca) models were employed to compute the wealth index.