Micronutrient deficiencies, especially vitamin A, iron, folate, and iodine, are highly prevalent in low- and middle-income countries (LMIC) (1, 2). Micronutrients contribute to poor health (3), retarded growth, low productivity, growth impairment, and unexpected death (4–7). The burden of disease due to the health effects of micronutrient deficiencies has received increased attention in the last few decades (3). Women and children are at a higher risk of developing micronutrient deficiencies, with pronounced effects during preconception, pregnancy, and lactation (8, 9). These conditions are aggravated by low levels of household dietary diversity (4) and household food insecurity (10).

Vitamin A deficiency (VAD) is considered one of the most serious public health concerns in LMIC. Young children and pregnant women, especially in low-income, rural communities, are more susceptible to VAD. Vitamin A is an essential micronutrient for normal functioning of the visual system, growth, and development, as well as maintenance of epithelial cellular integrity, immune function, and reproduction (11). VAD, defined as serum retinol concentrations below 0.825 μmol/l (12), is estimated to affect two billion people globally (7, 13). The initial symptoms of VAD include impaired adaptation to the dark with serum retinol concentrations falling below 0.8 μmol/L (14). Xeropthalmia, an advanced condition of VAD that can lead to blindness, is a concern for pregnant women given greater vitamin A requirements during this period of the life course (7).

Globally, evidence supports dietary diversification for optimal nutrition and health (15, 16). Consumption of diverse diets is central to achieving and preserving nutrient adequacy throughout the life course (15, 16). Inadequate dietary quantity and quality result in deficiencies of essential nutrients, particularly during pregnancy and lactation (17). In China, inadequate consumption of fruits and vegetables was associated with low levels of serum vitamin A among lactating women (18). In Ethiopia, more than 70% of pregnant women had low dietary diversity scores and low consumption of animal sourced foods (19) and 60% of lactating women had inadequate consumption of vitamin A rich foods (20). Diets of healthy women of reproductive age in Indonesia were considered low in animal sourced foods and fruit and vegetable consumption, suggesting greater risk of nutrient deficiencies (21). Understanding barriers to consumption of vitamin-A rich foods is critical to food-based programming, especially in post conflict regions of the world which are prone to drought and other conditions that exacerbate food insecurity.

Despite the progress in addressing vitamin A deficiency in LMICs, including Uganda, it is still a persistent public health concern. In Uganda, the prevalence of VAD is 8.3 and 9.0% in the urban and rural areas, respectively (22). Higher prevalence rates have been reported in the following subregions of Uganda: Acholi (15.4%), Busoga (12.8%), and West Nile (11.2%) (22). High implementation costs of industrial food fortification and supplementation programs, and their limited reach in resource-poor rural communities, justify continued support of alternative food-based approaches such as diet diversification and the biofortification of daily staple crops, such as orange-fleshed sweet potatoes (OFSP), with vitamin A (23). Innovative food-based approaches have included production of beta-carotene rich OFSP as a preventive and therapeutic nutrition-specific intervention targeting livelihoods that can also potentially prevent and mitigate vitamin A deficiency (24).

More research is needed on dietary patterns related to consumption of vitamin A rich foods, including OFSP, among women during pregnancy and the postpartum period (25, 26). A better understanding of dietary patterns, including vitamin A rich food consumption such as intake of OFSP, can lead to improved interventions to prevent malnutrition and improve maternal and child health outcomes related to VAD and other micronutrient deficiencies. Examination of dietary patterns also has implications for dietary guidelines (27), which can subsequently lead to increased understanding of the mechanisms that facilitate higher consumption of vitamin A rich foods and improved vitamin A status among women. This study examined consumption patterns of vitamin A rich foods, including OFSP, and assessed the predictive capacity of knowledge of vitamin A rich foods, knowledge of OFSP, and misconceptions of OFSP on vitamin A rich food consumption among women from OFSP-growing households in two regions of Uganda.

Mean age was 28.3 ±6.9 and 73.2% of all respondents were in the 20–34 age category. Most of the respondents were married (88.1%) and 78.2% had seven or less years of formal schooling. A majority of the women either pregnant (16.8%) or lactating (79.6%) at the time of data collection. Most households (66.5%) had between 5 and 9 members and were engaged in farming. Seventy-seven percent of the women consumed four or fewer food groups in the week preceding the survey (Table 1).

Our findings contribute to the literature on predictors of vitamin A rich food consumption. Based on the Hellen Keller assessment guide (32), the study population was found to be at a high risk for vitamin A deficiency given that the consumption patterns of vitamin A rich foods for women were relatively low with a mean weighted score below the threshold of adequate consumption. This is compounded by findings that suggest generally low knowledge about vitamin A was observed in this sample where a significant proportion of women were either pregnant or lactating at the time of data collection. These stages of the life course have higher vitamin A requirements and low intakes during these stages are associated with adverse health consequences (38). Recommendations are based on the expected secretion of retinol into human breast milk which is dependent on the mothers' vitamin A status, with the expectation that infants would also benefit (39). Breast milk is a fundamental source of vitamin A, especially in the first 6 months of life (40). Given the critical role of vitamin A in infant health and development, it is essential that women of reproductive age get adequate vitamin A and other micronutrients (41).

The targeted regions are post conflict areas of Uganda that experience greater food and nutrition insecurity due to food shortages and disrupted economic activities. In Uganda, like in many other developing countries, large scale programs are needed to make a significant impact on high rates of malnutrition, including VAD. However, there has been limited experience and success in scaling up programs (42). Based on the weighted consumption score, which found that nearly all women consumed low amounts of both animal and plant sources of vitamin A, the surveyed communities are considered to be at a high risk for VAD. Plant foods were the most frequent sources of vitamin A compared to animal sources of vitamin A which influences vitamin A status due to bioavailability of carotenoids (43).

The vitamin A rich food consumption patterns of the participating communities were not uniquely different and accentuated the reliance on plant source diets in limited resource settings in Sub Saharan Africa. Animal source foods are associated with higher serum retinol levels (44), however, are less affordable for low income populations (45). Previous studies corroborate our findings, suggesting that individuals from resource-constrained settings have limited access to foods containing preformed vitamin A from animal-based food sources and they do not commonly consume available foods containing beta-carotene due to poverty or lack of information on the importance of the food sources (46).

Nutrition education has the potential to increase knowledge of nutrition benefits among at-risk communities to improve consumption of carotenoids, including of OFSP, mangoes, papaya and dark leafy green vegetables and diversification to include animal sources of vitamin A (47). However, we observed a significant and inverse association between knowledge of vitamin A and vitamin A rich food consumption, after adjusting for covariates. This suggests that despite gains in nutrition knowledge, other barriers may play a role in the levels of consumption of vitamin A rich foods in these regions of Uganda. Some consumption barriers could include lack of access of vitamin A rich foods due to seasonal variation, especially among small holder subsistence farmers who are commonly stricken by poverty (48).

Seasonal variation in food supply can be addressed by growth of drought-resistant and dry season crops, such as tubers, which can alleviate food insecurity, although they may not necessarily be the best sources of vitamin A (49). Leafy green vegetables and OFSP were the commonly consumed sources of vitamin A in this population. Being seasonal crops, this translates into reduced consumption during out of season periods. Seasonality needs to be considered for consistent vitamin A intake across the year. Having the potential to purchase or grow other sources in the market during off seasons is a strategy to be considered in program interventions. Education and peer mentoring on home-based gardens for alternative vitamin A sources during periods of food insecurity, especially in the dry season, could prove to be instrumental in mitigating malnutrition (50, 51).

Vitamin A rich plant foods could also be readily available in the community but likely underutilized. In these situations, existing cultural practices that prohibit pregnant and lactating women from consuming potentially good sources of vitamin A may pose another barrier to consumption that may need to be abated (52, 53). Targeted nutrition education can be incorporated in food-based programs to increase community knowledge on ways to improve health outcomes, including bioavailability and absorption of vitamin A from plant sources (42, 54). Education can include preparation methods that allow the addition of fat to increase bioavailability of vitamin A which is fat soluble and can be stored in the body (55). An intervention study, with nutrition education, conducted among adolescent girls in Sri Lanka resulted in a highly significant (P < 0.001) increase in knowledge and consumption of local vitamin A rich foods (56). The percentage of adolescent girls with low serum retinol concentrations (<20 microg/dL) decreased from 17 to 4.8% as a result of the intervention (56).

Similar to this study, low dietary diversity was highly prevalent among pregnant women (N = 104) in the Damot Sore district of Southern Ethiopia (57). Another studies in Ethiopia reported that one quarter of households had low dietary diversity (58) or low to medium dietary diversity (20). In contrast, a study among 624 lactating mothers attending an immunization clinic in Gondar town, Ethiopia, determined that women had adequate vitamin A consumption with a greater proportion of women consuming more than five food groups (20). Nutrition knowledge was also found to be higher among women attending an immunization clinic in Gondar town, Ethiopia (20).The difference in vitamin A rich food intake in these Ethiopian communities might be explained by the women in Gondar having access to health care, experiencing greater food security, and residing in a semi-urban area of the country.

We found that knowledge of vitamin A was a statistically significant predictor of vitamin A rich consumption after adjusting for covariates. Similarly, knowledge was a predictor of vitamin A rich food consumption in a Nepali study (59). However, no statistically significant association was found between knowledge of vitamin A and vitamin A rich food consumption among lactating women in two regions of Tanzania (60). While age, education, household size, and individual dietary diversity were not predictors of vitamin A rich food consumption in this study, other studies suggest otherwise (21, 60, 61). Having a college degree, family size, and being from a higher economic class were identified as factors associated with vitamin A consumption in an Ethiopian study (20). Given that the study was conducted in an urban setting, it is possible women who attended the clinic in this town setting were more educated, knowledgeable, and economically well off (20) compared to women in our study who lived in post-conflict areas and relied on farming income. A study conducted in northern Benin where 34% of women were identified as being at a greater risk of VAD, found that maternal education, maternal farming activity, maternal health status, low food diversity, lack of fruit and vegetable consumption, low protein food consumption, and high infection rates were associated with the vitamin A status (61). In a study of 569 lactating mothers in Tanzania, the prevalence of VAD was 88.5% and was associated with place of residence (60). Sixty-eight percent of the lactating mothers in this Tanzanian study lacked knowledge about vitamin A and fortified oil, however they had a positive attitude toward the consumption of vitamin A rich foods (60). These findings suggest benefits of nutrition education, specifically on vitamin A and its health benefits, in low-resourced communities (60).

Our study contributes to scientific knowledge on predictors of vitamin A rich food consumption in low resource rural settings with subsistence farming activity. The results of this study will inform the International Potato Center's (CIP) implementation and scaling up of initiatives related to OFSP in selected post conflict regions in Uganda; adjustments to the initiative that improve nutrition education and remove consumption barriers can promote program effectiveness related to improved vitamin A rich food consumption within these communities.

By the time this paper was written, scaling up the program for the delivery of biofortified OFSP had begun to improve accessibility which may have translated into higher consumption among participating communities.

CIP is partnering with humanitarian agencies such as the World Food Programme (WFP) to make OFSP available for improving nutrition and livelihoods of vulnerable populations. This project is built on the premise that the proven nutrition and livelihood benefits of OFSP can be delivered efficiently through existing large-scale humanitarian programs, especially because these transition into market-based approaches that engage local and national agri-food systems to respond to and reduce the need for humanitarian food aid. Sweet potatoes and specifically OFSP, is new in the farming and food systems of the targeted regions. The intervention with the introduction of OFSP in these drought-prone post conflict regions has shown that the crop is an important part of the local diet and food system, where roots and leaves are both consumed as part of a healthy diet. The results of this study provide the CIP with important lessons on barriers to consumption, opportunities to improve uptake, and ultimately on strategies for scaling up of OFSP to improve the nutritional status, livelihoods, and food security status of these vulnerable populations.

Limitations include the lack of serum level data for assessment of vitamin A status of our participants. Although vitamin A consumption was computed from the Hellen Keller International guide which has been validated against acceptable standards, it is still possible underestimation of vitamin A consumption may have occurred based on the vulnerable population of women and the local environment. In addition, responses to the questionnaire could have been prone to both recall and social desirability bias. Finally, food practices/patterns could be unique to the post conflict situation of the rural areas of Uganda. Results may not be generalizable to populations in other regions or urban areas of Uganda.

We found that the study population was considered to be at high risk for VAD. Knowledge of vitamin A rich foods was an inverse and significant predictor of vitamin A rich food consumption among women, suggesting other barriers to uptake of these foods. Components of food insecurity such as availability, affordability, utilization, and changing food preferences may contribute to the unexpected inverse relationship between knowledge and consumption of Vitamin A rich foods. Scaling up biofortified food initiatives, including OFSP, can improve consumption of vitamin A rich foods with effective strategies to comprehensively address consumption barriers such as lack of nutrition education, cooking skills, and storage facilities, as well as low production levels and perceived contamination of biofortified foods. The results of the study suggest that food-based interventions addressing vitamin A rich food consumption through scaling up of biofortified foods, such as orange-fleshed sweet potatoes, consider opportunities to address the broad range of consumption barriers that persist despite gains in nutrition knowledge.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The study involving human participants was reviewed and approved by the Makerere University School of Health Sciences Institutional Review Board and received a waiver from the University of Massachusetts Amherst subject protection committee. Written informed consent from the participants' legal guardian/next of kin was not required to participate in this study in accordance with the national legislation and the institutional requirements.

JN and LC drafted the manuscript. JN, LC, LS, FG, NK, and SH contributed to the conception of the study. FG, NK, and SH collected the data and were responsible for data preparation. LC, LS, EM, and FG reviewed the manuscript and critically revised it for important content. SH assisted with additional research resources. All authors read and approved the final manuscript.