Abstract
<title>Abstract</title> <p>Background The acceptability of nutritional supplements is a key determinant of uptake and adherence; however, information on pregnant women’s preferences for multiple-tablet supplementation regimens and dosing schedules remains limited. This study used a mixed-methods approach to assess acceptability and preferences for MMS and calcium supplementation among pregnant women in Tanzania. Methods A mixed-methods acceptability study combined quantitative survey data with qualitative in-depth interviews. Participants (n = 50) evaluated four regimens: 250mg calcium, 500mg calcium, MMS, and MMS plus 500mg calcium. Regimens differed in tablet count, size, and formulation, and participants were shown the supplements and sachets in different formats. Participants also reported their preferred supplement format (tablet versus food-based preparation). Quantitative data were summarized descriptively, and qualitative data were analyzed thematically to explore the reasons underlying acceptability and preferences. Results About half (48%) of participants preferred a supplement dose of three small tablets, while 66% disliked the single, larger tablet that combined MMS and 500mg calcium. Overall, 44% preferred tablets, compared with 30% who chose food-based supplements taken directly and 26% who chose formulations mixed into food. Qualitative results showed that acceptability was mainly shaped by perceived benefits, ease of swallowing, tablet size and shape, and the burden of taking multiple or large tablets. Although some participants liked the convenience of a single tablet, most preferred several small round tablets over a single large oval tablet. Tablets were also preferred for familiarity and simplicity, while concerns about food-based supplements included altered taste or smell, nausea, and interference with eating. A small number of participants preferred powdered supplements mixed into beverages, citing ease of use. Conclusion We found that acceptability and preferences for MMS + calcium supplement varied among pregnant women and were influenced by perceived benefits, physical features, dosing schedules, and supplement formats. These findings emphasize the importance of user-centered regimen development and program messaging, and suggest that offering multiple formats and easy-to-manage dosing options could enhance acceptability and support adherence to the use of nutritional supplements in public health programs.</p>