Dietary supplements play an important role in the lives of many people living with chronic and often life-threatening medical conditions. Dietary supplements generally consist of diverse products that are typically not part of current mainstream, conventional health care [1]. Concerns about dietary supplements generally stem from the potential for adverse interactions with conventional medicines and patients replacing evidence-based health care with untested remedies[2]. Studies show that dietary supplements are often used by people living with HIV infection. The most common dietary supplements in people living with HIV/AIDS (PLWH) are used to 'boost immune functioning' such as mega-dose vitamins, and anti-oxidants and body cleansing products such as teas and herbs to remove 'toxins'[3]. As many as half of PLWH may use complementary and alternative medicines, which can include dietary supplements [4].

Dietary supplement users tend to engage in a range of health promoting behaviors [3, 5]. Studies of cancer patients show that actively seeking health information from multiple sources is a associated with dietary supplement use [6]. It is common for PLWH who use dietary supplements to conceal these practices from their health care providers, potentially increasing the risks for interference with treatment plans[5]. PLWH who use dietary supplements with the potential for adverse drug interactions are also inclined to seek health information from a variety of sources [4], including non-traditional and fringe groups, suggesting a vulnerability to misinformation and fraudulent claims.

Access to credible health information on the internet can be an important part of patient-centered health care. Unfortunately, the internet is also a major source of medical misinformation and unconventional health promotion. Incomplete and inaccurate health information is common on the internet and for many patients unreliable information sources are indistinguishable from credible ones [7–10]. Unproven cancer treatments promoted online, for example, cause significant concern and have led to measures that counter their use [11]. Similarly, South African courts have banned the promotion of vitamins to cure AIDS [12–14], after years of devastating government support for fake AIDS treatments [15–17]. Anecdote-based remedies are appealing to patients with serious health conditions because they speak in certain terms about their successes, emphasize the uncertainties and side-effects of conventional medicine, prey upon anxieties, and offer unrealistic hope [6]. Among PLWH, unsubstantiated claims by marketers of 'immune boosting products' and fake cures are often seen as credible and evoke interest in their use [9]. However, we are not aware of research that has investigated vulnerability to medical misinformation and fake claims among dietary supplement users living with HIV/AIDS.

The purpose of the present study was to examine dietary supplement use among PLWH and its association to vulnerability to medical misinformation. First, we describe past and current use of dietary supplements in a community sample of PLWH. We then describe the demographics, health characteristics, and information seeking behaviors of current dietary supplement users compared to persons not using dietary supplements. Finally, we tested the potential vulnerability to medical misinformation among active dietary supplement users. We focused on responses to claims that HIV/AIDS can be effectively treated and cured by dietary supplements. We hypothesized that PLWH who are using dietary supplements would be more interested in and believe the claims of medical misinformation propagated on the Internet.

Results of the current study demonstrated that one in four participants currently used at least one dietary supplement product. The overall use of dietary supplements in this sample was similar to past research with other medical populations. For example, a study of chronic lymphocytic leukemia patients found that 44% had used dietary supplements [26]. Previous research with PLWH also demonstrated similar use, such as a study of HIV positive men that found 69% used complementary medicine products and practices, the most common of which were dietary supplements [4].

The current study found that age and years of education were the only demographic characteristics associated with dietary supplement use; individuals who used dietary supplements were younger and significantly better educated. With respect to health markers, dietary supplement users were more likely to have an undetectabale viral load. It is important to note that while some dietary supplements can adversely interact with prescriprition medications, some supplements may also have positive impacts on HIV disease processes. For exampe, recent research suggests that selenium, which was used by 5% of our sample, may have benefits in treating HIV infection [27].

In the current study there was no association between supplement use and medication adherence, suggesting that participants may consider dietary supplements as co-treatments that do not interfere with their medications. Consistent with past research, we also found that dietary supplement use was associated with an array of health-related behaviors. In this case, dietary supplement users were significantly more likely to use the Internet for health-related information seeking. In addition to actively seeking health information on the internet, dietary supplement users also demonstrated greater trust in internet information and more positive beliefs in the curative value of dietary supplements. In addition, dietary supplement users were more inclined to believe and trust both unfounded claims as well as credible health information. These results confirm our main study hypothesis to show that dietary supplement use is associated with accepting medical misinformation. Our cross-sectional study, however, does not allow us to infer directions of the relationships. Specifically, people who use dietary supplements may be more vulnerable to misinformation or misinformed individuals may be more prone to using dietary supplements. These results also replicate previous research that has found high-rates of trust and believability in false claims on the internet among PLWH [23, 24]. Taken together, our findings suggest that dietary supplement use may be a marker for health seeking behaviors and an openness to using diverse treatment approaches regardless of their evidence-base, suggesting a vulnerability to quackery and fraud.

The findings from this study should be interpreted in light of its methodological limitations. With the exception of viral load assessed by blood labs and medication adherence monitored using an objective assessment, our study methods relied on self-reported health status and behaviors. As noted above, our cross-sectional study design precludes any causal or directional conclusions. The content of our measures may also have influenced our findings. Specifically, our measure of dietary supplement beliefs did not necessarily include items most central to decisions about using or not using dietary supplements. Our measures also may have excluded important covariates that could help explain the results, such as illicit substance use and medication side effects. It is also unknown whether responding to the study measures inadvertently stimulated interest or reinforced interest in dietary supplements. Finally, our results are based on a convenience sample that is predominantly middle-aged, African American, and from one southern US city. In addition, our recruitment procedures may have biased the sample toward recruiting networks of people who use dietary supplements. Although our results converge with other studies, caution is warranted before generalizing these findings to other populations of PLWH.

Dietary supplements play important roles in the health practices of many PLWH. Dietary supplement use often occurs in the context of antiretroviral therapies. Patients who gravitate toward alternative treatments should be counseled on the potential for misinformation and fraud on the Internet. The value of legitimate dietary supplements can be undermined by fraudulent and confusing medical misinformation on the Internet. Patient education and counseling about dietary supplement practices should occur while respecting well-informed individual choices in health care. Interventions that teach patients health consumer and critical thinking skills have demonstrated positive outcomes, including reduced vulnerability to internet-based misinformation [10]. Wide-scale use of the internet and the proliferation of e-health products challenges providers to discuss unfounded claims as well as the relative value of dietary supplements with their patients.