This study aims to analyze the effect of an improvised user-generated health awareness campaign which was based on a personal narrative and first-hand experience with the B12 deficiency symptoms in babies and toddlers. The campaign was conducted in 2015 with a follow-up video in 2016 and shared through social media outlets, informing about the topic and empowering individuals to take responsibility for their own or their child’s health by providing information that could serve as a guideline for early diagnosis and intervention and by presenting an outlook of how people with similar issues manage the condition. The impact of the campaign is being qualitatively and quantitatively accessed by interviews with medical professionals and respectively survey data from a national survey and statistics from the YouTube console. In consideration has been taken the trust the respondents have in the medical service and the usual access to health information both online and offline The quantitative data were collected using a national online survey in which 1185 individuals took part. It aimed to additionally identify the general public attitude towards medical service in and the awareness about the vitamin B12. Four people participated in the interviews, divided into two groups - parents of children, who had symptoms similar to those, shown in the videos; and health practitioners who have seen the videos and comment on its qualities as a self-diagnosing material as well as the effect that attention to the issue created on their medical practices. The results confirmed that the personal narrative of a campaign could help to create identification and thus be more persuasive and with further increased sharing potential of the message through social media. The concrete campaign reached cumulatively over 167.000 people through YouTube, which is around 2.4% of the population of Bulgaria and possibly creating a lasting impact on the public attitude towards vitamin/mineral and other deficiencies. We found out that social media and YouTube could serve as an impactful medium for disseminating health-related information online when accurate and persuasive information is being used. When addressing a wide audience with little or no prior knowledge of the subject the personal narrative or testimonial could create more impact than a neutral fact-providing material.